Search for the production of four top quarks in the single-lepton and opposite-sign dilepton final states in proton-proton collisions at $\sqrt{s} =$ 13 TeV

TL;DR

This paper reports a search for four top quark production in proton-proton collisions at 13 TeV using CMS data, setting upper limits on the production cross section and combining results with previous analyses.

Contribution

It introduces a multivariate analysis method to discriminate four top quark events from background and provides the first combined measurement with previous CMS results.

Findings

No significant excess observed over background.

Upper limit on four top quark production cross section is 48 fb.

Combined analysis yields a cross section of 13^{+11}_{-9} fb.

Abstract

A search for the standard model production of four top quarks (pp $\to$ $\mathrm{t\bar{t}t\bar{t}}$) is reported using single-lepton plus jets and opposite-sign dilepton plus jets signatures. Proton-proton collisions are recorded with the CMS detector at the LHC at a center-of-mass energy of 13 TeV in a sample corresponding to an integrated luminosity of 35.8 fb$^{-1}$. A multivariate analysis exploiting global event and jet properties is used to discriminate $\mathrm{t\bar{t}t\bar{t}}$ from $\mathrm{t\bar{t}}$ production. No significant deviation is observed from the predicted background. An upper limit is set on the cross section for $\mathrm{t\bar{t}t\bar{t}}$ production in the standard model of 48 fb at 95% confidence level. When combined with a previous measurement by the CMS experiment from an analysis of other final states, the observed signal significance is 1.4 standard deviations, and the combined cross section measurement is 13 $^{+11}_{-9}$ fb. The result is also interpreted in the framework of effective field theory.

Tables

	${\sigma }_k^{\left(1\right)}$			${\sigma }_{j,k}^{\left(2\right)}$
Operator		${𝒪}_{\text{cPqt}\text{cPqt}}^1$	${𝒪}_{\text{cmsSymbolFace}Q\text{cmsSymbolFace}Q}^1$	${𝒪}_{\text{cmsSymbolFace}Q\text{cPqt}}^1$	${𝒪}_{\text{cmsSymbolFace}Q\text{cPqt}}^8$
${𝒪}_{\text{cPqt}\text{cPqt}}^1$	0.39	5.59	0.36	$-$0.39	0.3
${𝒪}_{\text{cmsSymbolFace}Q\text{cmsSymbolFace}Q}^1$	0.47		5.49	$-$0.45	0.13
${𝒪}_{\text{cmsSymbolFace}Q\text{cPqt}}^1$	0.03			1.9	$-$0.08
${𝒪}_{\text{cmsSymbolFace}Q\text{cPqt}}^8$	0.28				0.45

Operator	Expected $C_k/{\Lambda }^2$ (${\text{TeVns}}^{-2}$)	Observed (${\text{TeVns}}^{-2}$)
${𝒪}_{\text{cPqt}\text{cPqt}}^1$	[$-$2.0, 1.8]	[$-$2.1, 2.0]
${𝒪}_{\text{cmsSymbolFace}Q\text{cmsSymbolFace}Q}^1$	[$-$2.0, 1.8]	[$-$2.2, 2.0]
${𝒪}_{\text{cmsSymbolFace}Q\text{cPqt}}^1$	[$-$3.3, 3.2]	[$-$3.5, 3.5]
${𝒪}_{\text{cmsSymbolFace}Q\text{cPqt}}^8$	[$-$7.3, 6.1]	[$-$7.9, 6.6]

Operator	Expected $C_k/{\Lambda }^2$ (${\text{TeVns}}^{-2}$)	Observed (${\text{TeVns}}^{-2}$)
${𝒪}_{\text{cPqt}\text{cPqt}}^1$	[$-$2.0, 1.9]	[$-$2.2, 2.1]
${𝒪}_{\text{cmsSymbolFace}Q\text{cmsSymbolFace}Q}^1$	[$-$2.0, 1.9]	[$-$2.2, 2.0]
${𝒪}_{\text{cmsSymbolFace}Q\text{cPqt}}^1$	[$-$3.4, 3.3]	[$-$3.7, 3.5]
${𝒪}_{\text{cmsSymbolFace}Q\text{cPqt}}^8$	[$-$7.4, 6.3]	[$-$8.0, 6.8]

Equations

$${\mathcal{L}}_{\text{EFT}}={\mathcal{L}}_{\text{SM}}^{\left(4\right)}+\frac{1}{\Lambda }\sum _k{C}_k^{\left(5\right)}{\mathcal{O}}_k^{\left(5\right)}+\frac{1}{{\Lambda }^2}\sum _k{C}_k^{\left(6\right)}{\mathcal{O}}_k^{\left(6\right)}+\dots ,$$

$${\mathcal{O}}_{\text{cPqt}\text{cPqt}}^1$$

$${\mathcal{O}}_{\text{cmsSymbolFace}Q\text{cmsSymbolFace}Q}^1$$

$${\mathcal{O}}_{\text{cmsSymbolFace}Q\text{cPqt}}^1$$

$${\mathcal{O}}_{\text{cmsSymbolFace}Q\text{cPqt}}^8$$

$${\sigma }_{\text{cPqt}\text{cPaqt}\text{cPqt}\text{cPaqt}}={\sigma }_{\text{cPqt}\text{cPaqt}\text{cPqt}\text{cPaqt}}^{\text{SM}}+\frac{1}{{\Lambda }^2}\sum _k{C}_k{\sigma }_k^{\left(1\right)}+\frac{1}{{\Lambda }^4}\sum _{j\le k}{C}_j{C}_k{\sigma }_{j,k}^{\left(2\right)},$$

$${\sigma }_{\text{cPqt}\text{cPaqt}\text{cPqt}\text{cPaqt}}={\sigma }_{\text{cPqt}\text{cPaqt}\text{cPqt}\text{cPaqt}}^{\text{SM}}+\frac{1}{{\Lambda }^2}{\vec{\mathbf{C}}}^{\mathbf{T}}\cdot {\vec{\mathbf{\sigma }}}^{\left(1\right)}+\frac{1}{{\Lambda }^4}{\vec{\text{C}}}^{\text{T}}{\mathbf{\sigma }}^{\left(2\right)}\vec{\mathbf{C}}.$$

Full text

0.1 Introduction

Many models of physics beyond the standard model (BSM) predict enhanced or modified couplings of top quarks to other particles. This is particularly relevant for processes that have small production cross sections and, therefore, are yet to be observed, such as the production of four top quarks, $\cPqt\cPaqt\cPqt\cPaqt$. There is considerable interest in the measurement of the $\cPqt\cPaqt\cPqt\cPaqt$ cross section because of its sensitivity to BSM physics, including supersymmetry [1, 2], composite models [3], top quark compositeness [4], two-Higgs-doublet models [5, 6, 7], and models with extra spatial dimensions [8, 9]. Within the effective field theory (EFT) framework, the contribution of any BSM process to $\cPqt\cPaqt\cPqt\cPaqt$ production can be parameterized in terms of nonrenormalizable effective couplings of the standard model (SM) fields, if the characteristic energy scale, $\Lambda$, of the BSM physics is much larger than the typical energy scale of $\cPqt\cPaqt\cPqt\cPaqt$ production at the LHC. A generic interpretation of the $\cPqt\cPaqt\cPqt\cPaqt$ production can be done using the EFT predictions [10].

The production of four top quarks from proton-proton ($\Pp\Pp$) interactions $\Pp\Pp\to\cPqt\cPaqt\cPqt\cPaqt$ has not yet been observed. The SM predicts a cross section, at next-to-leading order (NLO), with electroweak corrections (EWK), of $\sigma_{\cPqt\cPaqt\cPqt\cPaqt}^{\text{SM}}$ of $12.0$\unitfb at the center-of-mass energy of 13\TeV [11]. To facilitate comparison with published ATLAS and CMS analyses using comparable data sets, the NLO quantum chromodynamics (QCD) calculation with a value of $\sigma_{\cPqt\cPaqt\cPqt\cPaqt}^{\text{SM}}=9.2$\unitfb is used [12, 13]. Consequently, the experiments at the CERN LHC may be just approaching sensitivity to the process, provided that it can be separated from the overwhelming background from SM $\ttbar$ events. The lowest-order Feynman diagrams illustrating typical contributions to SM four top quark production in $\Pp\Pp$ collisions are shown in Fig. 1.

Searches for $\cPqt\cPaqt\cPqt\cPaqt$ production have been performed at 8\TeVby ATLAS [14, 15, 16] and CMS[17], and also at 13\TeV(ATLAS (36.1\fbinv[18, 19]) and CMS (2.6\fbinv[20])). The CMS Collaboration measured the $\cPqt\cPaqt\cPqt\cPaqt$ production cross section in a search exploiting same-sign dilepton and multilepton signatures [21, 22] using 13\TeVdata (35.9\fbinv) collected in 2016. The ATLAS Collaboration investigated anomalous $\cPqt\cPaqt\cPqt\cPaqt$ production in events with Lorentz-boosted top quarks identified with top quark tagging techniques [23] using 13\TeVdata (36.1\fbinv) collected in 2015–2016.

This paper presents a new search in the single-lepton (SL) (\PGm, \Pe)+jets and opposite-sign dilepton (DL) ($\MM$, $\PGmpm\Pemp$, or $\EE$)+jets $\cPqt\cPaqt\cPqt\cPaqt$ decay channels using $\Pp\Pp$ collisions at 13\TeVcollected by the CMS experiment in 2016 and corresponding to an integrated luminosity of $35.8$ \fbinv. For this analysis, only final states containing one or two leptons are considered, which constitute about 40% of all $\cPqt\cPaqt\cPqt\cPaqt$ decays. Compared to the previous analysis [20], we have implemented a number of important changes which combine to give a much improved analysis sensitivity. The training process and selection of the input variables for the event-discriminating MVA’s (Section 0.4.2) in both the SL and OS dilepton channels has been re-optimized. A new categorization of the signal sensitive regions at large jet and b-tag multiplicities has been introduced, and a revised binning scheme is used to decrease the statistical uncertainties, and improve the signal sensitivity. The categorisation provides additional discrimination against the rare \ttbar+boson (H, Z, W, WW/WZ/ZZ) backgrounds. Lastly, a much larger simulated \ttbardata set is used to populate the discriminant bins with high jet multiplicity and high b-tag multiplicity.

0.2 The CMS detector

The central feature of the CMS apparatus is a superconducting solenoid of 6\unitm internal diameter, providing a magnetic field of 3.8\unitT. Within the solenoid volume are a silicon pixel and strip tracker, a lead tungstate crystal electromagnetic calorimeter, and a brass and scintillator hadron calorimeter, each composed of a barrel and two endcap sections. Forward calorimeters extend the pseudorapidity coverage ($\eta$) provided by the barrel and endcap detectors. Muons are measured in gas-ionization detectors embedded in the steel flux-return yoke outside the solenoid, in the range $\abs{\eta}<2.4$. A more detailed description of the CMS detector, together with a definition of the coordinate system used and the relevant kinematic variables, can be found in Ref. [24].

0.3 Simulated samples

The acceptance for the SM $\Pp\Pp\to\cPqt\cPaqt\cPqt\cPaqt$ process is estimated using samples simulated at NLO precision by the \MGvATNLO2.2.2 generator [13, 25]. Only diagrams arising from quantum chromodynamics interactions were taken into account in the simulation. The cross section used to normalize the simulation is the NLO calculation of $9.2^{+2.9}_{-2.4}$ \unitfb [13], where the quoted uncertainty incorporates the variation of factorization and renormalization scales used in the calculation of the matrix elements (ME), and the dependence on the choice of parton distribution functions (PDFs). The signal model includes MadSpin [26] and uses the default dynamic scale choice in \MGvATNLO, defined as $\mu_{\mathrm{R,F}}=\frac{1}{2}\Sigma_{\PQt}m_{\mathrm{T}}$. This is the sum of $m_{\mathrm{T}}$ over each outgoing parton (the four top quarks), divided by two, where $m_{\mathrm{T}}=\sqrt{m^{2}+\pt^{2}}$, in which $m$ is the mass of the parton, and \ptis the transverse momentum.

The most important background process is top quark pair production with additional jets ($\ttbar{+}\text{jets}$), that comprises over 90-95% of the background. Next in importance are single top (ST) quark processes including $t$-channel and $\PQt\PW$ production. These are followed by $\PZ{+}\text{jets}$ and $\PW{+}\text{jets}$ electroweak processes (EW), where only the leptonic decay modes of the bosons are considered. Next are rare processes involving the production of a top quark-antiquark pair and a \PZ, \PW, or Higgs bosons, namely, \ttbar+\PZ,\PW,\PH. Finally, \ttbarproduction in association with dibosons, $\ttbar\PW\PW$, $\ttbar\PW\PZ$, $\ttbar\PZ\PZ$, $\ttbar\PW\PH$, $\ttbar\PZ\PW$, $\ttbar\PH\PH$, and triple top quark production ($\ttbar\PQt{+}\text{jets}$ and $\ttbar\PQt\PW$) are considered, processes we collectively denote as $\cPqt\cPaqt\text{XY}$. Based on their signature resemblance and comparability of production rates to the $\cPqt\cPaqt\cPqt\cPaqt$ signal, \ttbar+\PZand \ttbar+\PHare grouped together while \ttbar+\PW and $\cPqt\cPaqt\text{XY}$ are grouped together in the simulation.

Several Monte Carlo (MC) event generators are used to simulate these processes. The $\ttbar{+}\text{jets}$ process is simulated using the \POWHEG-box v2 generator [27, 28, 29, 30, 31] at NLO accuracy for the \ttbarME, but the \ttbarcross section is normalized to its predicted value at next-to-next-to-leading order (NNLO), which includes soft-gluon corrections, at next-to-next-to-leading-logarithm accuracy, obtained with Top++ 2.0 [32, 33, 34, 35, 36, 37, 38]. The \POWHEG-box simulations are interfaced with \PYTHIA8.212 using the CUETP8M2T4 tune [39, 40, 41]. Recent calculations [38] suggest that next-to-next-to-leading-order effects have an important consequence on the shape of the top quark \PTspectrum that NLO ME generators are unable to reproduce. To allow for this, a parton-level reweighting of the \ttbarsimulation has been applied to match the predictions to the data [42, 43]. The correction is applied as a function of the transverse momenta of the parton-level top quark and antiquark after initial- and final-state radiation. Specifically for this result, additional dedicated samples were created that populate the tails in high multiplicity with a factor of 10 more events.

Single top quark $\PQt\PW$ processes are simulated with the \POWHEG-box v1 generator [44], while $t$-channel processes are simulated with \POWHEG-box v2. Both are interfaced with \PYTHIA8.212 using the CUETP8M2T4 tune, with the cross sections normalized to the NLO calculations [45, 46]. The analysis has been shown [20] to be insensitive to other ST quark production processes, such as $s$-channel production.

Events with massive gauge bosons and no top quarks ($\PZ{+}\text{jets}$, $\PW{+}\text{jets}$) are simulated using \MGvATNLO [13] at leading-order (LO) accuracy, with up to four additional partons in the ME calculations, and using the MLM matching scheme [47]. The tune CUETP8M1 is used for the parton shower (PS) and underlying event (UE) modeling. These samples are normalized to their NNLO cross sections [48].

The production of a \ttbarpair in association with a \PW, \PZand up to one extra parton is simulated using the \MGvATNLOgenerator at LO accuracy and matched with the PS predictions using the MLM matching scheme. Top quark pair production in association with a Higgs boson, $\ttbar\PH$, is modeled using \POWHEG-box v2, interfaced with \PYTHIA8.212 with the CUETP8M2T4 tune. In this sample, only the dominant $\PH\to\bbbar$ decays are taken into account. These three samples are normalized to the NLO cross sections [49]. Top quark pair production in association with one or two massive bosons is simulated using the LO ME in the \MGvATNLOgenerator, and the CUETP8M2T4 tune of \PYTHIA8.212 to provide the PS. The cross sections are scaled to their LO values [49].

For the samples with NLO MEs, the NNPDF3.0NLO [50] PDFs are used, while for LO MEs, the corresponding NNPDF3.0LO PDFs are used. The parton shower, hadronization, and underlying event models implemented in \PYTHIA8.212 [51] are used to simulate higher-order processes and nonperturbative aspects of $\Pp\Pp$ collisions. The NLO simulations use strong coupling constant values of $\alpS(M_{\PZ})=0.137$ and $\alpS(M_{\PZ})=0.113$ for the ME and PS modeling, and the LO simulations use $\alpS(M_{\PZ})=0.130$ for the ME. In all simulations involving the top quark, a mass $m_{\PQt}$ of 172.5\GeVis used.

The \PYTHIACUETP8M2T4 tune [39, 40, 41] currently provides the best description of the \ttbardata [52, 53]. The \POWHEG-box calculation describes the high-multiplicity tail when this tune is used. The uncertainties cover the differences due to alternative choices of the PS and hadronization models [54].

All of the simulated samples include an estimate of the additional $\Pp\Pp$ interactions per bunch crossing (pileup), modeled with the \PYTHIA8.212 program. Corrections are applied to make the simulation of the number of additional interactions representative of that observed in the data. The simulated events are propagated through a simulation of the CMS detector based on \GEANTfour(v.9.4) [55] and reconstructed using the same algorithms as for the collider data.

0.4 Data analysis

0.4.1 Event selection

The final states considered in this analysis are the single-lepton channel with exactly one muon or electron, (\PGm, \Pe)+jets, and the opposite-sign dilepton channel, ($\MM$, $\PGmpm\Pemp$, $\EE$)+jets. In all cases, the leptons are expected to originate from the \PW bosons arising from top quark decays and thus tend to be isolated, unlike the leptons produced in the decay of unstable hadrons within jets.

Single-lepton events were recorded using a trigger [56] that required at least one isolated muon with $\PT>24\GeV$ and $\abs{\eta}<2.4$, or one isolated electron with $\PT>32\GeV$ and $\abs{\eta}<2.1$. Dilepton events were recorded using either single-lepton or dilepton triggers. In the case of dilepton triggers, the \PTthresholds for the leading and subleading leptons for the dimuon triggers are 17 and 8\GeV, respectively, 23 and 12\GeVfor dielectron triggers, and 23 and 8\GeVfor muon-electron triggers, regardless of lepton flavor. Dilepton triggers require $\abs{\eta}<2.4$ for muons and $\abs{\eta}<2.5$ for electrons. The single-lepton triggers were also used in the dilepton channel to increase the efficiency, while retaining the orthogonality of the selections addressing the two final states.

Offline event reconstruction uses the CMS particle-flow (PF) algorithm [57] for particle reconstruction and identification. Single-lepton events are required to have exactly one isolated muon with $\PT>26\GeV$ or one isolated electron with $\PT>35\GeV$, either within $\abs{\eta}<2.1$. In the dilepton channel, events are required to contain exactly two isolated leptons of opposite sign with $\PT>25\GeV$ for the leading and $\PT>20\GeV$ for the subleading lepton, within $\abs{\eta}<2.4$. Muons must satisfy the criteria described in Ref. [58] and have a relative isolation, $I_{\text{rel}}<0.15$. Electron candidates must satisfy stringent identification criteria, including $I_{\text{rel}}$, which are described in Ref. [59]. The $I_{\text{rel}}$ is defined as the scalar \ptsum of the additional particles consistent with the same vertex as the lepton, within a cone of angular radius $\Delta R=\sqrt{\smash[b]{(\Delta\eta)^{2}+(\Delta\phi)^{2}}}$ = 0.4 around the lepton, divided by the \ptof the lepton, where $\Delta\eta$ and $\Delta\phi$ (in radians) are the differences in pseudorapidity and azimuthal angle, respectively, between the directions of the lepton and the additional particle. The sum is corrected for the neutral particle contribution from pileup on an event-by-event basis [59, 58]. To suppress background events from decays of low-mass resonances and \PZ bosons, the lepton pairs are required to have an invariant mass greater than 20\GeVand be outside of a 30\GeVwindow centered on the \PZ boson mass in both the $\MM$ and $\EE$ channels. Events containing additional muons with looser relative isolation, $I_{\text{rel}}<0.25$, or isolated electrons are vetoed.

Each event is required to contain at least one reconstructed vertex. The reconstructed vertex with the largest value of the quadratic sum of the \PTof its associated tracks is considered the primary $\Pp\Pp$ interaction vertex. Jets are reconstructed from the PF candidates using the infrared- and collinear-safe anti-\ktalgorithm [60, 61] with a distance parameter of 0.4. Pileup interactions can contribute tracks and calorimetric energy depositions to the jet momentum. To mitigate this effect, charged particles identified as originating from pileup vertices are discarded and the jet is corrected for the remaining contributions [62, 63]. Jet energy corrections are derived from simulations to bring the measured response of jets to that of particle level jets on average. In situ measurements of the momentum balance in dijet, $\text{photon}{+}\text{jet}$, $\PZ{+}\text{jet}$, and multijet events are used to account for any residual differences in jet energy scale between real and simulated data [64]. The jet energy resolution is typically 15% at 10\GeV, 8% at 100\GeV, and 4% at 1\TeV. The missing transverse momentum vector \ptvecmissis computed as the negative vector sum of \PTof all the PF candidates in an event, and its magnitude is denoted as \ptmiss [65]. The quantity \ptvecmissis modified to account for corrections to the energy of the reconstructed jets in the event.

A minimum of seven jets for the single-muon and eight jets for the single-electron channel are required, each of which must have $\PT>30\GeV$ and $\abs{\eta}<2.5$. The difference in the jet multiplicity is motivated by the need to reduce the residual contamination from multijet QCD background in the electron channel due to a higher lepton misidentification rate. In the selected events, at least two jets must be tagged as originating from the hadronization of bottom quarks (\cPqb jets) using the combined secondary vertex (CSVv2) algorithm at its medium working point [66]. Additional \cPqb jet candidates are identified using the CSVv2 algorithm at its loose working point. The two working points, loose and medium, provide different levels of purity and efficiency. The loose working point gives a misidentification rate of approximately 10% for light-quark and gluon jets, with a \cPqb tagging efficiency of about 80%. The medium working point has a misidentification rate of about 1% with a \cPqb tagging efficiency of about 68%. The efficiency to tag \cPqcquarks is 12%. To suppress the small residual QCD background, \ptmissis required to be larger than $50$ \GeV. Studies on the estimation of non-prompt leptons from QCD multijet background by inverting lepton isolation selection criteria have verified that this background is negligible after applying the selection requirements. In addition, a requirement on the scalar sum of the \PTof all jets, $\HT>500\GeV$, is applied. The \HTrequirement is used to suppress the \ttbarbackground, while having little effect on the signal acceptance [20].

In the dilepton channels, a minimum of four jets is required, each with $\abs{\eta}<2.4$. Of these, at least two must be \cPqb-tagged using the same CSVv2 algorithm with medium working point as was used in the single-lepton channel. While the \PTthreshold for non-tagged jets is $30\GeV$ (as for the single-lepton channel), the threshold for \cPqb-tagged jets is lowered to $25\GeV$ to increase the acceptance for events with multiple \cPqb jets. The $\HT>500\GeV$ requirement is also applied to the dilepton channels.

Figures 2–5 show the comparison of the data and simulations after these selections have been applied for both the single-lepton and dilepton analyses. The simulation of $\ttbar{+}\text{jets}$ process is split into three categories: top quark pair associated with two additional light flavor or gluon jets (\ttbar+jj), top quark pair associated with a charm quark pair (\ttbar+$\ccbar$), and top quark pair associated with a bottom quark pair (\ttbar+$\bbbar$) [67]. The definitions of the variables in the figures are given in the next section.

0.4.2 Multivariate discriminants

Boosted decision trees (BDTs) [68, 69] are used in two roles in this analysis: to identify the top quarks and to improve the discrimination between signal and background. The jet multiplicity, jet properties and the number of the \cPqb jets, as well as associated kinematic variables, feature strongly in the choice of BDT input variables. The method is based on the strategies developed for the previous 13\TeVCMS analyses in the single-lepton and opposite-sign dilepton final states [20]. All BDTs are trained using the AdaBoost algorithm [70], as implemented in the tmva package [71], and return a discriminant as output.

The BDT for identifying hadronically decaying top quarks classifies combinations of three jets (trijet) on how consistent they are with the trijet originating from the all-hadronic decay of a top quark, rather than from other sources such as initial-state radiation (ISR) or final-state radiation (FSR). Its input variables consist of the invariant dijet and trijet masses, the \cPqb tagging information for the jet not associated to the dijet, and the angles between the three jets. This BDT is trained to distinguish between the three jets from a hadronically decaying top quark and any other permutation of 3-jet combinations using the ME information in tt+jets simulations.

Because of the high jet multiplicity in both signal and background events, many three-jet combinations are possible. The trijet permutations for each event are ranked according to their discriminant value, from highest to lowest. In the single-lepton channel, each \ttbarbackground event contains a genuine hadronic top quark decay, so the jets included in the first-ranked trijet ($T_{\text{trijet1}}$) are removed and the highest-ranked discriminant using the remaining jets ($T_{\text{trijet2}}$) is used. In the dilepton channels, the \ttbarbackground contains no hadronic top quark decays, so only the output for $T_{\text{trijet1}}$ is used as the discriminant.

The BDTs, yielding the discriminants for the single-lepton channel ($D_{\cPqt\cPaqt\cPqt\cPaqt}^{\text{SL}}$) and for the dilepton channel ($D_{\cPqt\cPaqt\cPqt\cPaqt}^{\text{DL}}$), use the discriminant from the trijet associations, described above, as one of its input variables. In the single-lepton channel, $D_{\cPqt\cPaqt\cPqt\cPaqt}^{\text{SL}}$ is trained separately for each jet multiplicity, and inclusively over the number of \cPqb-tagged jets. In the dilepton channel, the training is done unitarily for all jet multiplicities while separately in $\MM,\PGmpm\Pemp$, and $\EE$ states. The choice of input variables is optimized separately for the two channels and is based on the characteristics of the lepton and jet activity in the events. The resulting variable lists are different for the two channels. The variables can be grouped into three categories: event activity, event topology, and \cPqb quark multiplicity. Although many of the input variables are correlated, each one contributes some additional discrimination between the \ttbarbackground and the $\cPqt\cPaqt\cPqt\cPaqt$ signal.

Studies of the differences between the simulated \ttbarand $\cPqt\cPaqt\cPqt\cPaqt$ events have led to the selection of the following variables describing the hadronic activity in the event:

The number of jets present in the event, $N_{\mathrm{j}}$. 2. 2.

The scalar sum of the \ptof all medium working point \cPqb jets in the event, $\HT^{\text{\PQb}}$. 3. 3.

The ratio of the sum \HTof the four highest \ptjets in the event in the single-lepton channel, or the two jets with the highest \cPqb tagging discriminant in the dilepton channel, to the \HTof the other jets in the event, $\HT^{\text{ratio}}$. 4. 4.

The \HTsum in the event, subtracting the scalar \ptsum of the two highest \pt \cPqb jets, $\HT^{\text{2m}}$. 5. 5.

The transverse momenta of the jets with the third- and fourth-largest \ptin the event, $\pt^{\text{j3}}$ and $\pt^{\text{j4}}$. 6. 6.

The reduced event mass, $M_{\text{red}}^{\text{h}}$, defined as the invariant mass of the system comprising all the jets in the reduced event, where the reduced event is constructed by removing the jets contained in $T_{\text{trijet1}}$ in single-lepton events. In \ttbarevents, the reduced event will typically only contain the \cPqb jet from the semileptonic top quark decay and jets arising from ISR and FSR. Conversely, a reduced $\cPqt\cPaqt\cPqt\cPaqt$ event can contain up to two hadronically decaying top quarks and, as a result, a relatively high reduced event mass. 7. 7.

The reduced event \HT, $H_{\mathrm{T}}^{\mathrm{x}}$, is defined as the \HTof all jets in the single-lepton event selection excluding those contained in $T_{\text{trijet1}}$.

The event topology is characterized by the two variables:

Event sphericity, $S$, [72], calculated from all of the jets in the event in terms of the normalized tensor

$M^{\alpha\beta}={\sum_{i}p_{i}^{\alpha}p_{i}^{\beta}}/{\sum_{i}\abs{\vec{p_{i}}}^{2}},$

where $\alpha$ and $\beta$ refer to the three-components of the momentum of the $i$th jet. The sphericity is defined as $S=(3/2)(\lambda_{2}+\lambda_{3})$, where $\lambda_{2}$ and $\lambda_{3}$ are the two smallest eigenvalues of $M^{\alpha\beta}$. The sphericity in $\cPqt\cPaqt\cPqt\cPaqt$ events should differ from that in background \ttbarevents of the same energy, since the jets in \ttbarevents will be less isotropically distributed because of their recoil from sources such as ISR. 2. 2.

Hadronic centrality, $C$, defined as the value of \HTdivided by the sum of the energies of all jets in the event.

Since all these variables rely only on the hadronic information in the event, sensitivity to the lepton information is provided through the \ptand $\eta$ of the highest \ptlepton (or the only lepton for the single-lepton channel) $\left(\pt^{\ell 1},\eta^{\ell 1}\right)$ and the angular difference ($\Delta R_{\ell\ell}$) between the leptons in dilepton events. The \cPqb jet multiplicity is characterized in terms of the number of \cPqb jets tagged by the CSVv2 algorithm operating at its loose ($N_{\text{tags}}^{\text{l}}$) and medium ($N_{\text{tags}}^{\text{m}}$) operating points, and the angular separation $\Delta R_{\PQb\PQb}$ between the \cPqb-tagged jets with the highest CSVv2 discriminants. Finally, the third- and fourth-highest \cPqb tagging discriminant values are used as they allow separation between \ttbar+light jets, and genuine additional heavy-flavor jets, as present in $\cPqt\cPaqt\cPqt\cPaqt$ events.

The training variables were not changed as a function of final state or jet multiplicity. In the single-lepton channel, the optimal variable set, listed in the order of their discriminating power, is $T_{\text{trijet2}}$; $\HT^{\text{\PQb}}$; $C$; $\pt^{\ell 1}$; $M_{\text{red}}^{\text{h}}$; $H_{\mathrm{T}}^{\mathrm{x}}$; the third- and fourth-highest CSVv2 discriminants, and the \PTof those tagged jets; the $\PT$ for the first, second, fifth, and sixth jet. In the dilepton channel, the optimal variable set, listed in the order of their discriminating power, is $N_{\mathrm{j}}$, $T_{\text{trijet1}}$, $\HT^{\text{2m}}$, $\pt^{\text{j4}}$, $N_{\text{tags}}^{\text{l}}$, $\HT^{\text{ratio}}$, $\HT^{\text{\PQb}}$, $S$, $\Delta R_{\PQb\PQb}$, $N_{\text{tags}}^{\text{m}}$, $\Delta R_{\ell\ell}$, $C$, $\pt^{\text{j3}}$, $\pt^{\ell 1}$ and $\eta^{\ell 1}$. The MC modeling of the individual observables utilized in the discriminants $D_{\cPqt\cPaqt\cPqt\cPaqt}^{\text{SL}}$ and $D_{\cPqt\cPaqt\cPqt\cPaqt}^{\text{DL}}$ was verified using samples of \ttbarevents and found to be in agreement with the data for all the jet and \cPqb jet multiplicities.

0.5 Systematic uncertainties

The systematic uncertainties that affect this analysis can change the shape, or the normalization, or both, of the $D_{\cPqt\cPaqt\cPqt\cPaqt}^{\text{SL}}$ and $D_{\cPqt\cPaqt\cPqt\cPaqt}^{\text{DL}}$ discriminants. The uncertainties are characterized in Table 0.5. Each of the systematic uncertainty sources is modeled by one nuisance parameter. The normalization-dependent terms account for the uncertainties in the background yields, while the effect of the shape-dependent terms is evaluated using discriminant distributions whose shape has been modified by each of the uncertainties.

The experimental uncertainties considered are:

• •

Integrated luminosity: A 2.5% normalization uncertainty on the integrated luminosity [73].

• •

Pileup modeling: The number of pileup events in the simulation is matched to that of the data. The uncertainty due to this correction is estimated by using two sets of alternative weights derived with a variation of $\pm 4.6\%$ on the total inelastic $\Pp\Pp$ cross section [74].

• •

Lepton reconstruction and identification: The uncertainties in lepton identification, isolation, trigger efficiencies, and tracking efficiencies were examined. After a comparison between data and simulations, we assign a normalization uncertainty of 3% to take into account these effects.

• •

Jet energy corrections and resolutions: The uncertainties due to limited knowledge of the jet energy scale (JES) and the jet energy resolution (JER) are estimated by varying the $\eta$- and $\pt$-dependent JES and JER corrections of all jets by $\pm$1 standard deviation [64]. In the case of JES uncertainty, it was split into 6 components, which include uncertainties owing to the absolute jet-energy scale, the pileup offset, the extrapolation between samples of different jet-flavor composition, the parton fragmentation and underlying event modeling and residual time and $\eta$-dependent variations. Each component represents a quadratic sum of subsets of jet energy correction uncertainties from different sources. The effect of each component is evaluated separately.

• •

\cPqb

tagging: The uncertainty in the \cPqb tagging discriminant shape is estimated by varying the shape of the discriminant distribution according to its one standard deviation uncertainties in terms of the \PT, $\eta$, and flavor of the jets [67]. The variations correspond to uncertainties in the jet energy scale, background contamination of the samples used to derive them, and statistical uncertainties of these data samples.

Sources of systematic uncertainties originating from theory are listed below.

• •

Renormalization and factorization scales: In order to estimate the uncertainty arising from missing higher-order terms in the calculation of the signal and background cross sections, renormalization and factorization scales are each modified, independently, up and down by a factor of two relative to their nominal values. The cases in which the two scales are varied in opposite directions are excluded. This is estimated for both the \ttbarand $\cPqt\cPaqt\cPqt\cPaqt$ processes.

• •

Parton shower scales: The evolution scales in the initial- and final-state PSs are separately varied by a factor of 2 and $\sqrt{2}$, respectively, up and down relative to their nominal values, in order to estimate the uncertainty attributed to the shower model. This is estimated for both the \ttbarand $\cPqt\cPaqt\cPqt\cPaqt$ processes.

• •

ME-PS matching: The uncertainty resulting from this source is estimated by varying the \POWHEG-box PS scale parameter, $h_{\text{damp}}$, that controls the ME and PS matching and regulates the high-$\pt$ radiation, within its uncertainty by $\pm$1 standard deviation of the measured value $h_{\text{damp}}=1.581^{+0.658}_{-0.585}m_{\PQt}$ [54]. This is estimated for the \ttbarprocess.

• •

Underlying event: The uncertainty from the UE tune of \ttbarevent generator is evaluated by using simulations with varied parameters that are related to the CUETP8M2T4 tune [39]. This is estimated for the \ttbarprocess.

• •

Jet multiplicity correction: The modeling of $\ttbar{+}\text{jets}$ production in \POWHEG-box is insufficient to describe the data in the regions of large jet multiplicity. To allow for this, scale factors are determined from fits to the single-lepton data in the signal depleted regions ($N_{\mathrm{j}}=8$,9, and $N_{\text{tags}}^{\text{m}}=2$,3), and propagated to the signal sensitive regions. The scale factors determined in the single-lepton channel are also used in the dilepton channel taking into account the difference in the jet multiplicity between the two channels. The uncertainty resulting from this correction is 10% for the \ttbarprocess [53].

• •

Parton distribution functions: The PDF uncertainty [75] in \ttbarproduction is estimated by evaluating the shape difference between the nominal simulation and simulations based on the NNPDF [50], MMHT14 [76], and CT10 [77] PDF sets. This is estimated for the \ttbarprocess.

• •

Top quark \ptreweighting: The \ttbarsimulation is corrected to match the observed spectra [78, 79]. The uncertainty from the corrections made to the shape of the top quark \ptdistribution is estimated by allowing the correction function to vary within a $\pm$1 standard deviation uncertainty. This is estimated for the \ttbarprocess.

• •

Heavy-flavor reweighting: To correctly model the rate of additional heavy-flavor jets in \ttbarproduction, the uncertainty in the rate of \ttbar+\bbbaris taken from the $\pm$1 standard deviation uncertainty in the measured value [80]. This is estimated for the \ttbarprocess. As a cross-check, an independent uncertainty on \ttbar+$\ccbar$ production was added. The resulting effect on the expected sensitivity of the search was found to be negligible.

• •

Rare processes: Uncertainties from the cross sections of rare processes of \ttbarpair production in association with one or two massive gauge bosons and triple top quark production are taken into account by allowing them to vary within 50% of their SM value [21].

The simulated samples used to evaluate the PS, ME-PS and UE uncertainties are statistically limited, so these uncertainties are estimated conservatively by assigning the larger value between the statistical uncertainty of these simulated samples and the rate change of these simulated sample from the nominal simulation as uncertainty, independently for different jet multiplicities.

0.6 Results

A simultaneous binned maximum-likelihood template fit to the single-lepton, dilepton, and combined experimental results was used to determine the signal strength parameter, which is defined as the ratio of the observed and predicted SM $\cPqt\cPaqt\cPqt\cPaqt$ cross sections, $\mu=\sigma_{\cPqt\cPaqt\cPqt\cPaqt}^{\text{obs}}/\sigma_{\cPqt\cPaqt\cPqt\cPaqt}^{\text{SM}}$. To increase the sensitivity of the analysis, events are categorized depending on their jet and \cPqb-tagged jet multiplicities. In the single-lepton channel these categories are: $N_{\mathrm{j}}=7$, 8, 9, and $\geq$10 and $N_{\text{tags}}^{\text{m}}=2$, 3, and $\geq$4 in each jet multiplicity region. In the dilepton channel these are $N_{\mathrm{j}}=4$–5, 6–7, and $\geq$8 and $N_{\text{tags}}^{\text{m}}=2$, and $\geq$3 in each jet multiplicity region. In each category the binning was chosen to ensure at least 4 predicted background events per bin.

The likelihood function incorporates each of the systematic uncertainties in the signal and background $D_{\cPqt\cPaqt\cPqt\cPaqt}^{\text{DL}}$ and $D_{\cPqt\cPaqt\cPqt\cPaqt}^{\text{SL}}$ templates as nuisance parameters in the fit. The systematic uncertainties attributed to the trigger or specific to the jet or lepton reconstruction were treated as fully correlated among the different final states. The normalization uncertainties are included assuming a log-normal distribution for the nuisance parameters, while the shape uncertainties are included as Gaussian-distributed parameters.

All of the post-fit nuisance parameter values were found to be consistent with their initial values to well within their quoted uncertainties, indicating the consistency of the fit model with the observed data. Two of the post-fit nuisance parameters are significantly constrained by the fit. These correspond to the heavy-flavor reweighting and initial-state parton-shower radiation scale, which are reduced by 65% and 30%, respectively. The sensitivity of the analysis is affected almost equally by the statistical uncertainty and the combined systematic uncertainties. The leading sources of systematic uncertainty are the \ttbar+heavy-flavor production reweighting, the jet multiplicity correction, and the PS and UE modeling in \ttbarsimulation. The post-fit distributions in signal-enriched $N_{\mathrm{j}}$ and $N_{\text{tags}}^{\text{m}}$ categories are shown in Figs. 6–9 for the single-lepton channel and Figs. 11–12 for the dilepton channel.

No statistically significant deviation from the SM background prediction is observed in the $D_{\cPqt\cPaqt\cPqt\cPaqt}^{\text{DL}}$ or $D_{\cPqt\cPaqt\cPqt\cPaqt}^{\text{SL}}$ distributions. The corresponding observed and expected significance of the signal and the best fit value of the signal strength parameter are given together with the $\cPqt\cPaqt\cPqt\cPaqt$ cross section in Table 0.6. In order to quantify the experimental sensitivity of the search, the median expected significance is calculated assuming that the data are distributed according to the SM prediction with a nominal $\cPqt\cPaqt\cPqt\cPaqt$ production cross section value $\sigma_{\cPqt\cPaqt\cPqt\cPaqt}^{\text{SM}}$, corresponding to the signal strength modifier value $\mu=1$. An upper limit on the $\cPqt\cPaqt\cPqt\cPaqt$ production cross section is derived using the asymptotic approximation of the $\CLs$ method [81, 82, 83, 84, 85]. The observed and expected 95% confidence level (CL) upper limits from the two analyses and their combination are listed in Table 0.6. The expected upper limit on the $\cPqt\cPaqt\cPqt\cPaqt$ production is calculated under assumption of a background-only hypothesis, corresponding to the signal strength modifier $\mu=0$.

0.6.1 Combination with the same-sign dilepton and multileptons channels

An independent search for the SM $\cPqt\cPaqt\cPqt\cPaqt$ production has been performed previously in same-sign dilepton and multilepton channels [21]. This search is characterized by a different background composition which, in contrast to the single-lepton and opposite-sign dilepton searches, is composed of mainly the $\ttbar\PZ$ and $\ttbar\PW$ processes. In order to exploit the complementarity of this analysis, a combination of the results from single-lepton, opposite-sign, same-sign and multilepton channels has been performed. The combination is based on a binned likelihood function equal to a product of likelihood terms over all search regions considered in single-lepton, opposite-sign and same-sign dilepton and multilepton channels.

Because of different origins of the dominant background processes, the main systematic uncertainties in the three analyses are independent and can be treated as uncorrelated. Nevertheless, the stability of the combination with respect to the assumption on the correlations between common sources of systematic uncertainty was tested by repeating the fit with and without correlations between the corresponding nuisance parameters. The resulting changes in the signal strength and expected limit were found to be less than 1% of the corresponding total uncertainties and were therefore not included.

The combined expected and observed 95% CL upper limits on the $\cPqt\cPaqt\cPqt\cPaqt$ production are $20^{\,+\,10}_{\,-\,6}\unit{fb}$ and $33\unit{fb}$, respectively, which is about a 10% improvement on the precision of the measurement with respect to the multilepton analysis alone. A summary of upper limit determinations from the individual analyses and their combination is provided in Table 0.6.

0.6.2 Effective field theory interpretation

New physics may manifest itself as modified interactions of SM fields, even if the associated particles are too heavy to be directly probed at the LHC. Such interactions can be modeled by extending the SM Lagrangian with terms involving composite operators of SM fields. Assuming that these terms preserve the gauge symmetries of the SM, possible new interactions can be classified according to their scaling dimension and the SM fields content [86, 87, 88]. The EFT Lagrangian reads

[TABLE]

where $\mathcal{L}_{\text{SM}}^{\left(4\right)}$ is the SM Lagrangian, while $\mathcal{O}_{k}^{\left(n\right)}$ and $C_{k}^{\left(n\right)}$ denote dimension-$n$ (dim-$n$) composite operators and their coupling parameters, respectively. Each term in the sum is suppressed by $\Lambda^{n-4}$, where $\Lambda$ is an energy scale that characterizes the new physics and $n$ is the scaling dimension of the corresponding operator. The energy scale, $\Lambda$, is the scale below which on-shell effects of BSM physics can be neglected and is typically related to the mass scale of the hypothetical BSM states. The EFT approach is generic and, in principle, experimental constraints obtained within the EFT framework can be recast into bounds on parameters of any ultraviolet-complete new physics model.

The production of four top quarks is a unique signature that provides information about models that predict enhanced interactions of the third generation quarks, such as four-fermion $\cPqt\cPaqt\cPqt\cPaqt$ coupling. The dim-5 operators do not contribute to $\cPqt\cPaqt\cPqt\cPaqt$ production because they do not couple to top quarks [89]. A minimal basis of composite dim-6 operators contributing in Eq. (1) was derived in Ref. [87]. Only a small subset of these operators lead to four top quark production at LO in the EFT perturbation series. In a restricted scenario [90, 10], assuming that new physics couples predominantly to the left-handed doublet and right-handed up-type quark singlet of the third generation, only four operators are expected to contribute significantly to $\cPqt\cPaqt\cPqt\cPaqt$ production, namely,

[TABLE]

where $\cmsSymbolFace{Q}_{\cmsSymbolFace}{L}$ and $\cPqt_{\mathrm{R}}$ denote the left-handed third generation quark doublet and the right-handed top quark singlet, respectively. The 4-fermion $\ttbar\bbbar$ operators were not included because of the negligible \cPqb quark parton density in the proton. Leading order predictions for the $\Pp\Pp\to\cPqt\cPaqt\cPqt\cPaqt$ cross section can be parameterized using the equation

[TABLE]

where the linear terms, $C_{k}\sigma_{{k}}^{\left(1\right)}$, represent the interference of the SM production with the dim-6 EFT contribution, while the quadratic terms include two components: the square of the diagrams containing one EFT operator, and the interference term for two diagrams, each with one EFT operator. Representing $C_{k}$ as a column-vector, $\vec{\textbf{C}}$, Eq. (3) can be expressed in a matrix form as

[TABLE]

In order to find $\boldsymbol{\vec{\sigma}}^{\left(1\right)}$ and ${\boldsymbol{\sigma}}^{\left(2\right)}$, a system of linear equations has to be solved. It is obtained by substituting linearly-independent vectors $\vec{\boldsymbol{C}}$ into Eq. (4). In the cross section calculation, the EFT interactions are implemented in the FeynRules [90, 91] package and interfaced with \MGvATNLO [13]. The NNPDF3.0LO [50] PDF set and $\alpS(M_{\PZ})=0.138$ were used in the calculation. In the EFT predictions, the SM contribution, $\sigma_{\cPqt\cPaqt\cPqt\cPaqt}^{\text{SM}}$ in Eqs. (3) and (4), was rescaled to the NLO cross section of $9.2\unit{fb}$ for the collision energy of 13 \TeV. The linear and quadratic coefficients, $\sigma_{k}^{\left(1\right)}$ and $\sigma_{{j},{k}}^{\left(2\right)}$, in Eq. (3) can be found in Table 0.6.2.

The observed limit of $3.6\sigma_{\cPqt\cPaqt\cPqt\cPaqt}^{\text{SM}}$, with a corresponding expected limit of $3.2\sigma_{\cPqt\cPaqt\cPqt\cPaqt}^{\text{SM}}$ (assuming $\mu=1$), from the combined experimental results, is used to constrain possible contributions of EFT operators. Since the data are only sensitive to the ratios, $C_{k}/\Lambda^{2}$, the constraints are presented only for such ratios. In the limit setting, SM kinematics of the $\cPqt\cPaqt\cPqt\cPaqt$ final state were assumed and only rate information was utilized to calculate the constraints. Besides the NLO scale uncertainty from the SM $\cPqt\cPaqt\cPqt\cPaqt$ NLO prediction, no further scale uncertainties were added because other uncertainties on $\cPqt\cPaqt\cPqt\cPaqt$ production are already included in the experimental limit.

Independent limits were obtained under the assumption that only one operator contributes to the $\cPqt\cPaqt\cPqt\cPaqt$ cross section with the coefficients of the other operators set to zero. The intervals obtained are summarized in Table 0.6.2. More conservative estimates were obtained by marginalizing the contribution of other operators within the interval $C_{k}/\Lambda^{2}\in[-4\pi,4\pi]$, defined by the stability of perturbation series. The corresponding limits are listed in Table 0.6.2. The results obtained are only slightly weaker than independent constraints because of the small correlations between the operators.

As shown in Tables 0.6.2 and 0.6.2, the data have highest sensitivity to the contribution of $\mathcal{O}^{1}_{\cPqt\cPqt}$ and $\mathcal{O}_{\cmsSymbolFace{Q}\cmsSymbolFace{Q}}^{1}$. The allowed intervals for the coupling parameters are almost independent of the other considered operators and stay stable after marginalization.

0.7 Summary

A search for standard model $\cPqt\cPaqt\cPqt\cPaqt$ production has been performed in final states with one or two oppositely signed muons or electrons plus jets. The observed yields attributed to $\cPqt\cPaqt\cPqt\cPaqt$ production are consistent with the background predictions. An upper limit at 95% confidence level of $48$\unitfb is set on the cross section for $\cPqt\cPaqt\cPqt\cPaqt$ production. Combining this result with a previous same-sign dilepton and multilepton search [21] the resulting cross section is $13^{\,+\,11}_{\,-\,9}\unit{fb}$ with an observed significance of $1.4$ standard deviations. The combined result constitutes one of the most stringent constraints from CMS on the production of four top quarks and can be used for phenomenological reinterpretation of a wide range of new physics models. The experimental results are interpreted in the effective field theory framework and yield limits on dimension-6 four-fermion operators coupling to third generation quarks competitive with the latest ATLAS interpretation [18].

Acknowledgements.

We congratulate our colleagues in the CERN accelerator departments for the excellent performance of the LHC and thank the technical and administrative staffs at CERN and at other CMS institutes for their contributions to the success of the CMS effort. In addition, we gratefully acknowledge the computing centers and personnel of the Worldwide LHC Computing Grid for delivering so effectively the computing infrastructure essential to our analyses. Finally, we acknowledge the enduring support for the construction and operation of the LHC and the CMS detector provided by the following funding agencies: BMBWF and FWF (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, FAPERGS, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES and CSF (Croatia); RPF (Cyprus); SENESCYT (Ecuador); MoER, ERC IUT, PUT and ERDF (Estonia); Academy of Finland, MEC, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); NKFIA (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); MSIP and NRF (Republic of Korea); MES (Latvia); LAS (Lithuania); MOE and UM (Malaysia); BUAP, CINVESTAV, CONACYT, LNS, SEP, and UASLP-FAI (Mexico); MOS (Montenegro); MBIE (New Zealand); PAEC (Pakistan); MSHE and NSC (Poland); FCT (Portugal); JINR (Dubna); MON, RosAtom, RAS, RFBR, and NRC KI (Russia); MESTD (Serbia); SEIDI, CPAN, PCTI, and FEDER (Spain); MOSTR (Sri Lanka); Swiss Funding Agencies (Switzerland); MST (Taipei); ThEPCenter, IPST, STAR, and NSTDA (Thailand); TUBITAK and TAEK (Turkey); NASU and SFFR (Ukraine); STFC (United Kingdom); DOE and NSF (USA). Individuals have received support from the Marie-Curie program and the European Research Council and Horizon 2020 Grant, contract Nos. 675440, 752730, and 765710 (European Union); the Leventis Foundation; the A.P. Sloan Foundation; the Alexander von Humboldt Foundation; the Belgian Federal Science Policy Office; the Fonds pour la Formation à la Recherche dans l’Industrie et dans l’Agriculture (FRIA-Belgium); the Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium); the F.R.S.-FNRS and FWO (Belgium) under the “Excellence of Science – EOS” – be.h project n. 30820817; the Beijing Municipal Science & Technology Commission, No. Z181100004218003; the Ministry of Education, Youth and Sports (MEYS) of the Czech Republic; the Lendület (“Momentum”) Program and the János Bolyai Research Scholarship of the Hungarian Academy of Sciences, the New National Excellence Program ÚNKP, the NKFIA research grants 123842, 123959, 124845, 124850, 125105, 128713, 128786, and 129058 (Hungary); the Council of Science and Industrial Research, India; the HOMING PLUS program of the Foundation for Polish Science, cofinanced from European Union, Regional Development Fund, the Mobility Plus program of the Ministry of Science and Higher Education, the National Science Center (Poland), contracts Harmonia 2014/14/M/ST2/00428, Opus 2014/13/B/ST2/02543, 2014/15/B/ST2/03998, and 2015/19/B/ST2/02861, Sonata-bis 2012/07/E/ST2/01406; the National Priorities Research Program by Qatar National Research Fund; the Ministry of Science and Education, grant no. 3.2989.2017 (Russia); the Programa Estatal de Fomento de la Investigación Científica y Técnica de Excelencia María de Maeztu, grant MDM-2015-0509 and the Programa Severo Ochoa del Principado de Asturias; the Thalis and Aristeia programs cofinanced by EU-ESF and the Greek NSRF; the Rachadapisek Sompot Fund for Postdoctoral Fellowship, Chulalongkorn University and the Chulalongkorn Academic into Its 2nd Century Project Advancement Project (Thailand); the Welch Foundation, contract C-1845; and the Weston Havens Foundation (USA).

.8 The CMS Collaboration

\cmsinstskip

**Yerevan Physics Institute, Yerevan, Armenia

** A.M. Sirunyan${}^{\textrm{\textdagger}}$, A. Tumasyan \cmsinstskip**Institut für Hochenergiephysik, Wien, Austria

** W. Adam, F. Ambrogi, T. Bergauer, J. Brandstetter, M. Dragicevic, J. Erö, A. Escalante Del Valle, M. Flechl, R. Frühwirth\cmsAuthorMark1, M. Jeitler\cmsAuthorMark1, N. Krammer, I. Krätschmer, D. Liko, T. Madlener, I. Mikulec, N. Rad, J. Schieck\cmsAuthorMark1, R. Schöfbeck, M. Spanring, D. Spitzbart, W. Waltenberger, C.-E. Wulz\cmsAuthorMark1, M. Zarucki \cmsinstskip**Institute for Nuclear Problems, Minsk, Belarus

** V. Drugakov, V. Mossolov, J. Suarez Gonzalez \cmsinstskip**Universiteit Antwerpen, Antwerpen, Belgium

** M.R. Darwish, E.A. De Wolf, D. Di Croce, X. Janssen, J. Lauwers, A. Lelek, M. Pieters, H. Rejeb Sfar, H. Van Haevermaet, P. Van Mechelen, S. Van Putte, N. Van Remortel \cmsinstskip**Vrije Universiteit Brussel, Brussel, Belgium

** F. Blekman, E.S. Bols, S.S. Chhibra, J. D’Hondt, J. De Clercq, D. Lontkovskyi, S. Lowette, I. Marchesini, S. Moortgat, L. Moreels, Q. Python, K. Skovpen, S. Tavernier, W. Van Doninck, P. Van Mulders, I. Van Parijs \cmsinstskip**Université Libre de Bruxelles, Bruxelles, Belgium

** D. Beghin, B. Bilin, H. Brun, B. Clerbaux, G. De Lentdecker, H. Delannoy, B. Dorney, L. Favart, A. Grebenyuk, A.K. Kalsi, J. Luetic, A. Popov, N. Postiau, E. Starling, L. Thomas, C. Vander Velde, P. Vanlaer, D. Vannerom, Q. Wang \cmsinstskip**Ghent University, Ghent, Belgium

** T. Cornelis, D. Dobur, I. Khvastunov\cmsAuthorMark2, C. Roskas, D. Trocino, M. Tytgat, W. Verbeke, B. Vermassen, M. Vit, N. Zaganidis \cmsinstskip**Université Catholique de Louvain, Louvain-la-Neuve, Belgium

** O. Bondu, G. Bruno, C. Caputo, P. David, C. Delaere, M. Delcourt, A. Giammanco, V. Lemaitre, A. Magitteri, J. Prisciandaro, A. Saggio, M. Vidal Marono, P. Vischia, J. Zobec \cmsinstskip**Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro, Brazil

** F.L. Alves, G.A. Alves, G. Correia Silva, C. Hensel, A. Moraes, P. Rebello Teles \cmsinstskip**Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil

** E. Belchior Batista Das Chagas, W. Carvalho, J. Chinellato\cmsAuthorMark3, E. Coelho, E.M. Da Costa, G.G. Da Silveira\cmsAuthorMark4, D. De Jesus Damiao, C. De Oliveira Martins, S. Fonseca De Souza, L.M. Huertas Guativa, H. Malbouisson, J. Martins\cmsAuthorMark5, D. Matos Figueiredo, M. Medina Jaime\cmsAuthorMark6, M. Melo De Almeida, C. Mora Herrera, L. Mundim, H. Nogima, W.L. Prado Da Silva, L.J. Sanchez Rosas, A. Santoro, A. Sznajder, M. Thiel, E.J. Tonelli Manganote\cmsAuthorMark3, F. Torres Da Silva De Araujo, A. Vilela Pereira \cmsinstskip**Universidade Estadual Paulista a, Universidade Federal do ABC b, São Paulo, Brazil

** S. Ahujaa, C.A. Bernardesa, L. Calligarisa, T.R. Fernandez Perez Tomeia, E.M. Gregoresb, D.S. Lemos, P.G. Mercadanteb, S.F. Novaesa, SandraS. Padulaa \cmsinstskip**Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia, Bulgaria

** A. Aleksandrov, G. Antchev, R. Hadjiiska, P. Iaydjiev, A. Marinov, M. Misheva, M. Rodozov, M. Shopova, G. Sultanov \cmsinstskip**University of Sofia, Sofia, Bulgaria

** M. Bonchev, A. Dimitrov, T. Ivanov, L. Litov, B. Pavlov, P. Petkov \cmsinstskip**Beihang University, Beijing, China

** W. Fang\cmsAuthorMark7, X. Gao\cmsAuthorMark7, L. Yuan \cmsinstskip**Institute of High Energy Physics, Beijing, China

** M. Ahmad, G.M. Chen, H.S. Chen, M. Chen, C.H. Jiang, D. Leggat, H. Liao, Z. Liu, S.M. Shaheen\cmsAuthorMark8, A. Spiezia, J. Tao, E. Yazgan, H. Zhang, S. Zhang\cmsAuthorMark8, J. Zhao \cmsinstskip**State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing, China

** A. Agapitos, Y. Ban, G. Chen, A. Levin, J. Li, L. Li, Q. Li, Y. Mao, S.J. Qian, D. Wang \cmsinstskip**Tsinghua University, Beijing, China

** Z. Hu, Y. Wang \cmsinstskip**Universidad de Los Andes, Bogota, Colombia

** C. Avila, A. Cabrera, L.F. Chaparro Sierra, C. Florez, C.F. González Hernández, M.A. Segura Delgado \cmsinstskip**Universidad de Antioquia, Medellin, Colombia

** J. Mejia Guisao, J.D. Ruiz Alvarez, C.A. Salazar González, N. Vanegas Arbelaez \cmsinstskip**University of Split, Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, Split, Croatia

** D. Giljanović, N. Godinovic, D. Lelas, I. Puljak, T. Sculac \cmsinstskip**University of Split, Faculty of Science, Split, Croatia

** Z. Antunovic, M. Kovac \cmsinstskip**Institute Rudjer Boskovic, Zagreb, Croatia

** V. Brigljevic, S. Ceci, D. Ferencek, K. Kadija, B. Mesic, M. Roguljic, A. Starodumov\cmsAuthorMark9, T. Susa \cmsinstskip**University of Cyprus, Nicosia, Cyprus

** M.W. Ather, A. Attikis, E. Erodotou, A. Ioannou, M. Kolosova, S. Konstantinou, G. Mavromanolakis, J. Mousa, C. Nicolaou, F. Ptochos, P.A. Razis, H. Rykaczewski, D. Tsiakkouri \cmsinstskip**Charles University, Prague, Czech Republic

** M. Finger\cmsAuthorMark10, M. Finger Jr.\cmsAuthorMark10, A. Kveton, J. Tomsa \cmsinstskip**Escuela Politecnica Nacional, Quito, Ecuador

** E. Ayala \cmsinstskip**Universidad San Francisco de Quito, Quito, Ecuador

** E. Carrera Jarrin \cmsinstskip**Academy of Scientific Research and Technology of the Arab Republic of Egypt, Egyptian Network of High Energy Physics, Cairo, Egypt

** H. Abdalla\cmsAuthorMark11, A.A. Abdelalim\cmsAuthorMark12*,*\cmsAuthorMark13 \cmsinstskip**National Institute of Chemical Physics and Biophysics, Tallinn, Estonia

** S. Bhowmik, A. Carvalho Antunes De Oliveira, R.K. Dewanjee, K. Ehataht, M. Kadastik, M. Raidal, C. Veelken \cmsinstskip**Department of Physics, University of Helsinki, Helsinki, Finland

** P. Eerola, L. Forthomme, H. Kirschenmann, K. Osterberg, M. Voutilainen \cmsinstskip**Helsinki Institute of Physics, Helsinki, Finland

** F. Garcia, J. Havukainen, J.K. Heikkilä, T. Järvinen, V. Karimäki, R. Kinnunen, T. Lampén, K. Lassila-Perini, S. Laurila, S. Lehti, T. Lindén, P. Luukka, T. Mäenpää, H. Siikonen, E. Tuominen, J. Tuominiemi \cmsinstskip**Lappeenranta University of Technology, Lappeenranta, Finland

** T. Tuuva \cmsinstskip**IRFU, CEA, Université Paris-Saclay, Gif-sur-Yvette, France

** M. Besancon, F. Couderc, M. Dejardin, D. Denegri, B. Fabbro, J.L. Faure, F. Ferri, S. Ganjour, A. Givernaud, P. Gras, G. Hamel de Monchenault, P. Jarry, C. Leloup, E. Locci, J. Malcles, J. Rander, A. Rosowsky, M.Ö. Sahin, A. Savoy-Navarro\cmsAuthorMark14, M. Titov \cmsinstskip**Laboratoire Leprince-Ringuet, CNRS/IN2P3, Ecole Polytechnique, Institut Polytechnique de Paris

** C. Amendola, F. Beaudette, P. Busson, C. Charlot, B. Diab, G. Falmagne, R. Granier de Cassagnac, I. Kucher, A. Lobanov, C. Martin Perez, M. Nguyen, C. Ochando, P. Paganini, J. Rembser, R. Salerno, J.B. Sauvan, Y. Sirois, A. Zabi, A. Zghiche \cmsinstskip**Université de Strasbourg, CNRS, IPHC UMR 7178, Strasbourg, France

** J.-L. Agram\cmsAuthorMark15, J. Andrea, D. Bloch, G. Bourgatte, J.-M. Brom, E.C. Chabert, C. Collard, E. Conte\cmsAuthorMark15, J.-C. Fontaine\cmsAuthorMark15, D. Gelé, U. Goerlach, M. Jansová, A.-C. Le Bihan, N. Tonon, P. Van Hove \cmsinstskip**Centre de Calcul de l’Institut National de Physique Nucleaire et de Physique des Particules, CNRS/IN2P3, Villeurbanne, France

** S. Gadrat \cmsinstskip**Université de Lyon, Université Claude Bernard Lyon 1, CNRS-IN2P3, Institut de Physique Nucléaire de Lyon, Villeurbanne, France

** S. Beauceron, C. Bernet, G. Boudoul, C. Camen, N. Chanon, R. Chierici, D. Contardo, P. Depasse, H. El Mamouni, J. Fay, S. Gascon, M. Gouzevitch, B. Ille, Sa. Jain, F. Lagarde, I.B. Laktineh, H. Lattaud, M. Lethuillier, L. Mirabito, S. Perries, V. Sordini, G. Touquet, M. Vander Donckt, S. Viret \cmsinstskip**Georgian Technical University, Tbilisi, Georgia

** A. Khvedelidze\cmsAuthorMark10 \cmsinstskip**Tbilisi State University, Tbilisi, Georgia

** Z. Tsamalaidze\cmsAuthorMark10 \cmsinstskip**RWTH Aachen University, I. Physikalisches Institut, Aachen, Germany

** C. Autermann, L. Feld, M.K. Kiesel, K. Klein, M. Lipinski, D. Meuser, A. Pauls, M. Preuten, M.P. Rauch, C. Schomakers, J. Schulz, M. Teroerde, B. Wittmer \cmsinstskip**RWTH Aachen University, III. Physikalisches Institut A, Aachen, Germany

** A. Albert, M. Erdmann, S. Erdweg, T. Esch, B. Fischer, R. Fischer, S. Ghosh, T. Hebbeker, K. Hoepfner, H. Keller, L. Mastrolorenzo, M. Merschmeyer, A. Meyer, P. Millet, G. Mocellin, S. Mondal, S. Mukherjee, D. Noll, A. Novak, T. Pook, A. Pozdnyakov, T. Quast, M. Radziej, Y. Rath, H. Reithler, M. Rieger, J. Roemer, A. Schmidt, S.C. Schuler, A. Sharma, S. Thüer, S. Wiedenbeck \cmsinstskip**RWTH Aachen University, III. Physikalisches Institut B, Aachen, Germany

** G. Flügge, W. Haj Ahmad\cmsAuthorMark16, O. Hlushchenko, T. Kress, T. Müller, A. Nehrkorn, A. Nowack, C. Pistone, O. Pooth, D. Roy, H. Sert, A. Stahl\cmsAuthorMark17 \cmsinstskip**Deutsches Elektronen-Synchrotron, Hamburg, Germany

** M. Aldaya Martin, P. Asmuss, I. Babounikau, H. Bakhshiansohi, K. Beernaert, O. Behnke, U. Behrens, A. Bermúdez Martínez, D. Bertsche, A.A. Bin Anuar, K. Borras\cmsAuthorMark18, V. Botta, A. Campbell, A. Cardini, P. Connor, S. Consuegra Rodríguez, C. Contreras-Campana, V. Danilov, A. De Wit, M.M. Defranchis, C. Diez Pardos, D. Domínguez Damiani, G. Eckerlin, D. Eckstein, T. Eichhorn, A. Elwood, E. Eren, E. Gallo\cmsAuthorMark19, A. Geiser, J.M. Grados Luyando, A. Grohsjean, M. Guthoff, M. Haranko, A. Harb, A. Jafari, N.Z. Jomhari, H. Jung, A. Kasem\cmsAuthorMark18, M. Kasemann, H. Kaveh, J. Keaveney, C. Kleinwort, J. Knolle, D. Krücker, W. Lange, T. Lenz, J. Leonard, J. Lidrych, K. Lipka, W. Lohmann\cmsAuthorMark20, R. Mankel, I.-A. Melzer-Pellmann, A.B. Meyer, M. Meyer, M. Missiroli, G. Mittag, J. Mnich, A. Mussgiller, V. Myronenko, D. Pérez Adán, S.K. Pflitsch, D. Pitzl, A. Raspereza, A. Saibel, M. Savitskyi, V. Scheurer, P. Schütze, C. Schwanenberger, R. Shevchenko, A. Singh, H. Tholen, O. Turkot, A. Vagnerini, M. Van De Klundert, G.P. Van Onsem, R. Walsh, Y. Wen, K. Wichmann, C. Wissing, O. Zenaiev, R. Zlebcik \cmsinstskip**University of Hamburg, Hamburg, Germany

** R. Aggleton, S. Bein, L. Benato, A. Benecke, V. Blobel, T. Dreyer, A. Ebrahimi, A. Fröhlich, C. Garbers, E. Garutti, D. Gonzalez, P. Gunnellini, J. Haller, A. Hinzmann, A. Karavdina, G. Kasieczka, R. Klanner, R. Kogler, N. Kovalchuk, S. Kurz, V. Kutzner, J. Lange, T. Lange, A. Malara, D. Marconi, J. Multhaup, M. Niedziela, C.E.N. Niemeyer, D. Nowatschin, A. Perieanu, A. Reimers, O. Rieger, C. Scharf, P. Schleper, S. Schumann, J. Schwandt, J. Sonneveld, H. Stadie, G. Steinbrück, F.M. Stober, M. Stöver, B. Vormwald, I. Zoi \cmsinstskip**Karlsruher Institut fuer Technologie, Karlsruhe, Germany

** M. Akbiyik, C. Barth, M. Baselga, S. Baur, T. Berger, E. Butz, R. Caspart, T. Chwalek, W. De Boer, A. Dierlamm, K. El Morabit, N. Faltermann, M. Giffels, P. Goldenzweig, A. Gottmann, M.A. Harrendorf, F. Hartmann\cmsAuthorMark17, U. Husemann, S. Kudella, S. Mitra, M.U. Mozer, Th. Müller, M. Musich, A. Nürnberg, G. Quast, K. Rabbertz, M. Schröder, I. Shvetsov, H.J. Simonis, R. Ulrich, M. Weber, C. Wöhrmann, R. Wolf \cmsinstskip**Institute of Nuclear and Particle Physics (INPP), NCSR Demokritos, Aghia Paraskevi, Greece

** G. Anagnostou, P. Asenov, G. Daskalakis, T. Geralis, A. Kyriakis, D. Loukas, G. Paspalaki \cmsinstskip**National and Kapodistrian University of Athens, Athens, Greece

** M. Diamantopoulou, G. Karathanasis, P. Kontaxakis, A. Panagiotou, I. Papavergou, N. Saoulidou, A. Stakia, K. Theofilatos, K. Vellidis \cmsinstskip**National Technical University of Athens, Athens, Greece

** G. Bakas, K. Kousouris, I. Papakrivopoulos, G. Tsipolitis \cmsinstskip**University of Ioánnina, Ioánnina, Greece

** I. Evangelou, C. Foudas, P. Gianneios, P. Katsoulis, P. Kokkas, S. Mallios, K. Manitara, N. Manthos, I. Papadopoulos, J. Strologas, F.A. Triantis, D. Tsitsonis \cmsinstskip**MTA-ELTE Lendület CMS Particle and Nuclear Physics Group, Eötvös Loránd University, Budapest, Hungary

** M. Bartók\cmsAuthorMark21, M. Csanad, P. Major, K. Mandal, A. Mehta, M.I. Nagy, G. Pasztor, O. Surányi, G.I. Veres \cmsinstskip**Wigner Research Centre for Physics, Budapest, Hungary

** G. Bencze, C. Hajdu, D. Horvath\cmsAuthorMark22, F. Sikler, T.Á. Vámi, V. Veszpremi, G. Vesztergombi${}^{\textrm{\textdagger}}$ \cmsinstskip**Institute of Nuclear Research ATOMKI, Debrecen, Hungary

** N. Beni, S. Czellar, J. Karancsi\cmsAuthorMark21, A. Makovec, J. Molnar, Z. Szillasi \cmsinstskip**Institute of Physics, University of Debrecen, Debrecen, Hungary

** P. Raics, D. Teyssier, Z.L. Trocsanyi, B. Ujvari \cmsinstskip**Eszterhazy Karoly University, Karoly Robert Campus, Gyongyos, Hungary

** T. Csorgo, W.J. Metzger, F. Nemes, T. Novak \cmsinstskip**Indian Institute of Science (IISc), Bangalore, India

** S. Choudhury, J.R. Komaragiri, P.C. Tiwari \cmsinstskip**National Institute of Science Education and Research, HBNI, Bhubaneswar, India

** S. Bahinipati\cmsAuthorMark24, C. Kar, G. Kole, P. Mal, V.K. Muraleedharan Nair Bindhu, A. Nayak\cmsAuthorMark25, D.K. Sahoo\cmsAuthorMark24, S.K. Swain \cmsinstskip**Panjab University, Chandigarh, India

** S. Bansal, S.B. Beri, V. Bhatnagar, S. Chauhan, R. Chawla, N. Dhingra, R. Gupta, A. Kaur, M. Kaur, S. Kaur, P. Kumari, M. Lohan, M. Meena, K. Sandeep, S. Sharma, J.B. Singh, A.K. Virdi, G. Walia \cmsinstskip**University of Delhi, Delhi, India

** A. Bhardwaj, B.C. Choudhary, R.B. Garg, M. Gola, S. Keshri, Ashok Kumar, S. Malhotra, M. Naimuddin, P. Priyanka, K. Ranjan, Aashaq Shah, R. Sharma \cmsinstskip**Saha Institute of Nuclear Physics, HBNI, Kolkata, India

** R. Bhardwaj\cmsAuthorMark26, M. Bharti\cmsAuthorMark26, R. Bhattacharya, S. Bhattacharya, U. Bhawandeep\cmsAuthorMark26, D. Bhowmik, S. Dey, S. Dutta, S. Ghosh, M. Maity\cmsAuthorMark27, K. Mondal, S. Nandan, A. Purohit, P.K. Rout, A. Roy, G. Saha, S. Sarkar, T. Sarkar\cmsAuthorMark27, M. Sharan, B. Singh\cmsAuthorMark26, S. Thakur\cmsAuthorMark26 \cmsinstskip**Indian Institute of Technology Madras, Madras, India

** P.K. Behera, P. Kalbhor, A. Muhammad, P.R. Pujahari, A. Sharma, A.K. Sikdar \cmsinstskip**Bhabha Atomic Research Centre, Mumbai, India

** R. Chudasama, D. Dutta, V. Jha, V. Kumar, D.K. Mishra, P.K. Netrakanti, L.M. Pant, P. Shukla \cmsinstskip**Tata Institute of Fundamental Research-A, Mumbai, India

** T. Aziz, M.A. Bhat, S. Dugad, G.B. Mohanty, N. Sur, RavindraKumar Verma \cmsinstskip**Tata Institute of Fundamental Research-B, Mumbai, India

** S. Banerjee, S. Bhattacharya, S. Chatterjee, P. Das, M. Guchait, S. Karmakar, S. Kumar, G. Majumder, K. Mazumdar, N. Sahoo, S. Sawant \cmsinstskip**Indian Institute of Science Education and Research (IISER), Pune, India

** S. Chauhan, S. Dube, V. Hegde, A. Kapoor, K. Kothekar, S. Pandey, A. Rane, A. Rastogi, S. Sharma \cmsinstskip**Institute for Research in Fundamental Sciences (IPM), Tehran, Iran

** S. Chenarani\cmsAuthorMark28, E. Eskandari Tadavani, S.M. Etesami\cmsAuthorMark28, M. Khakzad, M. Mohammadi Najafabadi, M. Naseri, F. Rezaei Hosseinabadi \cmsinstskip**University College Dublin, Dublin, Ireland

** M. Felcini, M. Grunewald \cmsinstskip**INFN Sezione di Bari a, Università di Bari b, Politecnico di Bari c, Bari, Italy

** M. Abbresciaa**,b, C. Calabriaa**,b, A. Colaleoa, D. Creanzaa**,c, L. Cristellaa**,b, N. De Filippisa**,c, M. De Palmaa**,b, A. Di Florioa**,b, L. Fiorea, A. Gelmia**,b, G. Iasellia**,c, M. Incea**,b, S. Lezkia**,b, G. Maggia**,c, M. Maggia, G. Minielloa**,b, S. Mya**,b, S. Nuzzoa**,b, A. Pompilia**,b, G. Pugliesea**,c, R. Radognaa, A. Ranieria, G. Selvaggia**,b, L. Silvestrisa, R. Vendittia, P. Verwilligena \cmsinstskip**INFN Sezione di Bologna a, Università di Bologna b, Bologna, Italy

** G. Abbiendia, C. Battilanaa**,b, D. Bonacorsia**,b, L. Borgonovia**,b, S. Braibant-Giacomellia**,b, R. Campaninia**,b, P. Capiluppia**,b, A. Castroa**,b, F.R. Cavalloa, C. Cioccaa, G. Codispotia**,b, M. Cuffiania**,b, G.M. Dallavallea, F. Fabbria, A. Fanfania**,b, E. Fontanesi, P. Giacomellia, C. Grandia, L. Guiduccia**,b, F. Iemmia**,b, S. Lo Meoa**,\cmsAuthorMark29, S. Marcellinia, G. Masettia, F.L. Navarriaa**,b, A. Perrottaa, F. Primaveraa**,b, A.M. Rossia**,b, T. Rovellia**,b, G.P. Sirolia**,b, N. Tosia \cmsinstskip**INFN Sezione di Catania a, Università di Catania b, Catania, Italy

** S. Albergoa**,b,\cmsAuthorMark30, S. Costaa**,b, A. Di Mattiaa, R. Potenzaa**,b, A. Tricomia**,b,\cmsAuthorMark30, C. Tuve*a**,*b \cmsinstskip**INFN Sezione di Firenze a, Università di Firenze b, Firenze, Italy

** G. Barbaglia, R. Ceccarelli, K. Chatterjeea**,b, V. Ciullia**,b, C. Civininia, R. D’Alessandroa**,b, E. Focardia**,b, G. Latino, P. Lenzia**,b, M. Meschinia, S. Paolettia, G. Sguazzonia, D. Stroma, L. Viliania \cmsinstskip**INFN Laboratori Nazionali di Frascati, Frascati, Italy

** L. Benussi, S. Bianco, D. Piccolo \cmsinstskip**INFN Sezione di Genova a, Università di Genova b, Genova, Italy

** M. Bozzoa**,b, F. Ferroa, R. Mulargiaa**,b, E. Robuttia, S. Tosi*a**,*b \cmsinstskip**INFN Sezione di Milano-Bicocca a, Università di Milano-Bicocca b, Milano, Italy

** A. Benagliaa, A. Beschia**,b, F. Brivioa**,b, V. Cirioloa**,b,\cmsAuthorMark17, S. Di Guidaa**,b,\cmsAuthorMark17, M.E. Dinardoa**,b, P. Dinia, S. Fiorendia**,b, S. Gennaia, A. Ghezzia**,b, P. Govonia**,b, L. Guzzia**,b, M. Malbertia, S. Malvezzia, D. Menascea, F. Montia**,b, L. Moronia, G. Ortonaa**,b, M. Paganonia**,b, D. Pedrinia, S. Ragazzi*a**,b, T. Tabarelli de Fatisa**,b, D. Zuoloa**,*b \cmsinstskip**INFN Sezione di Napoli a, Università di Napoli ’Federico II’ b, Napoli, Italy, Università della Basilicata c, Potenza, Italy, Università G. Marconi d, Roma, Italy

** S. Buontempoa, N. Cavalloa**,c, A. De Iorioa**,b, A. Di Crescenzoa**,b, F. Fabozzia**,c, F. Fiengaa, G. Galatia, A.O.M. Iorioa**,b, L. Listaa**,b, S. Meolaa**,d,\cmsAuthorMark17, P. Paoluccia**,\cmsAuthorMark17, B. Rossia, C. Sciacca*a**,b, E. Voevodinaa**,*b \cmsinstskip**INFN Sezione di Padova a, Università di Padova b, Padova, Italy, Università di Trento c, Trento, Italy

** P. Azzia, N. Bacchettaa, A. Bolettia**,b, A. Bragagnolo, R. Carlina**,b, P. Checchiaa, P. De Castro Manzanoa, T. Dorigoa, U. Dossellia, F. Gasparinia**,b, U. Gasparinia**,b, A. Gozzelinoa, S.Y. Hoh, P. Lujan, M. Margonia**,b, A.T. Meneguzzoa**,b, J. Pazzinia**,b, N. Pozzobona**,b, M. Presillab, P. Ronchese*a**,b, R. Rossina**,b, F. Simonettoa**,b, A. Tiko, M. Tosia**,b, M. Zanettia**,b, P. Zottoa**,b, G. Zumerlea**,*b \cmsinstskip**INFN Sezione di Pavia a, Università di Pavia b, Pavia, Italy

** A. Braghieria, P. Montagnaa**,b, S.P. Rattia**,b, V. Rea, M. Ressegottia**,b, C. Riccardia**,b, P. Salvinia, I. Vai*a**,b, P. Vituloa**,*b \cmsinstskip**INFN Sezione di Perugia a, Università di Perugia b, Perugia, Italy

** M. Biasinia**,b, G.M. Bileia, C. Cecchia**,b, D. Ciangottinia**,b, L. Fanòa**,b, P. Laricciaa**,b, R. Leonardia**,b, E. Manonia, G. Mantovania**,b, V. Mariania**,b, M. Menichellia, A. Rossia**,b, A. Santocchiaa**,b, D. Spigaa \cmsinstskip**INFN Sezione di Pisa a, Università di Pisa b, Scuola Normale Superiore di Pisa c, Pisa, Italy

** K. Androsova, P. Azzurria, G. Bagliesia, V. Bertacchia**,c, L. Bianchinia, T. Boccalia, R. Castaldia, M.A. Cioccia**,b, R. Dell’Orsoa, G. Fedia, L. Gianninia**,c, A. Giassia, M.T. Grippoa, F. Ligabuea**,c, E. Mancaa**,c, G. Mandorlia**,c, A. Messineoa**,b, F. Pallaa, A. Rizzia**,b, G. Rolandi\cmsAuthorMark31, S. Roy Chowdhury, A. Scribanoa, P. Spagnoloa, R. Tenchinia, G. Tonellia**,b, N. Turini, A. Venturia, P.G. Verdinia \cmsinstskip**INFN Sezione di Roma a, Sapienza Università di Roma b, Rome, Italy

** F. Cavallaria, M. Cipriania**,b, D. Del Rea**,b, E. Di Marcoa**,b, M. Diemoza, E. Longoa**,b, B. Marzocchia**,b, P. Meridiania, G. Organtinia**,b, F. Pandolfia, R. Paramattia**,b, C. Quarantaa**,b, S. Rahatloua**,b, C. Rovellia, F. Santanastasio*a**,b, L. Soffia**,*b \cmsinstskip**INFN Sezione di Torino a, Università di Torino b, Torino, Italy, Università del Piemonte Orientale c, Novara, Italy

** N. Amapanea**,b, R. Arcidiaconoa**,c, S. Argiroa**,b, M. Arneodoa**,c, N. Bartosika, R. Bellana**,b, C. Biinoa, A. Cappatia**,b, N. Cartigliaa, S. Comettia, M. Costaa**,b, R. Covarellia**,b, N. Demariaa, B. Kiania**,b, C. Mariottia, S. Masellia, E. Migliorea**,b, V. Monacoa**,b, E. Monteila**,b, M. Montenoa, M.M. Obertinoa**,b, L. Pachera**,b, N. Pastronea, M. Pelliccionia, G.L. Pinna Angionia**,b, A. Romeroa**,b, M. Ruspaa**,c, R. Sacchia**,b, R. Salvaticoa**,b, V. Solaa, A. Solanoa**,b, D. Soldia**,b, A. Staianoa \cmsinstskip**INFN Sezione di Trieste a, Università di Trieste b, Trieste, Italy

** S. Belfortea, V. Candelisea**,b, M. Casarsaa, F. Cossuttia, A. Da Rolda**,b, G. Della Riccaa**,b, F. Vazzolera**,b, A. Zanettia \cmsinstskip**Kyungpook National University, Daegu, Korea

** B. Kim, D.H. Kim, G.N. Kim, M.S. Kim, J. Lee, S.W. Lee, C.S. Moon, Y.D. Oh, S.I. Pak, S. Sekmen, D.C. Son, Y.C. Yang \cmsinstskip**Chonnam National University, Institute for Universe and Elementary Particles, Kwangju, Korea

** H. Kim, D.H. Moon, G. Oh \cmsinstskip**Hanyang University, Seoul, Korea

** B. Francois, T.J. Kim, J. Park \cmsinstskip**Korea University, Seoul, Korea

** S. Cho, S. Choi, Y. Go, D. Gyun, S. Ha, B. Hong, K. Lee, K.S. Lee, J. Lim, J. Park, S.K. Park, Y. Roh \cmsinstskip**Kyung Hee University, Department of Physics

** J. Goh \cmsinstskip**Sejong University, Seoul, Korea

** H.S. Kim \cmsinstskip**Seoul National University, Seoul, Korea

** J. Almond, J.H. Bhyun, J. Choi, S. Jeon, J. Kim, J.S. Kim, H. Lee, K. Lee, S. Lee, K. Nam, M. Oh, S.B. Oh, B.C. Radburn-Smith, U.K. Yang, H.D. Yoo, I. Yoon, G.B. Yu \cmsinstskip**University of Seoul, Seoul, Korea

** D. Jeon, H. Kim, J.H. Kim, J.S.H. Lee, I.C. Park, I. Watson \cmsinstskip**Sungkyunkwan University, Suwon, Korea

** Y. Choi, C. Hwang, Y. Jeong, J. Lee, Y. Lee, I. Yu \cmsinstskip**Riga Technical University, Riga, Latvia

** V. Veckalns\cmsAuthorMark32 \cmsinstskip**Vilnius University, Vilnius, Lithuania

** V. Dudenas, A. Juodagalvis, J. Vaitkus \cmsinstskip**National Centre for Particle Physics, Universiti Malaya, Kuala Lumpur, Malaysia

** Z.A. Ibrahim, F. Mohamad Idris\cmsAuthorMark33, W.A.T. Wan Abdullah, M.N. Yusli, Z. Zolkapli \cmsinstskip**Universidad de Sonora (UNISON), Hermosillo, Mexico

** J.F. Benitez, A. Castaneda Hernandez, J.A. Murillo Quijada, L. Valencia Palomo \cmsinstskip**Centro de Investigacion y de Estudios Avanzados del IPN, Mexico City, Mexico

** H. Castilla-Valdez, E. De La Cruz-Burelo, I. Heredia-De La Cruz\cmsAuthorMark34, R. Lopez-Fernandez, A. Sanchez-Hernandez \cmsinstskip**Universidad Iberoamericana, Mexico City, Mexico

** S. Carrillo Moreno, C. Oropeza Barrera, M. Ramirez-Garcia, F. Vazquez Valencia \cmsinstskip**Benemerita Universidad Autonoma de Puebla, Puebla, Mexico

** J. Eysermans, I. Pedraza, H.A. Salazar Ibarguen, C. Uribe Estrada \cmsinstskip**Universidad Autónoma de San Luis Potosí, San Luis Potosí, Mexico

** A. Morelos Pineda \cmsinstskip**University of Montenegro, Podgorica, Montenegro

** N. Raicevic \cmsinstskip**University of Auckland, Auckland, New Zealand

** D. Krofcheck \cmsinstskip**University of Canterbury, Christchurch, New Zealand

** S. Bheesette, P.H. Butler \cmsinstskip**National Centre for Physics, Quaid-I-Azam University, Islamabad, Pakistan

** A. Ahmad, M. Ahmad, Q. Hassan, H.R. Hoorani, W.A. Khan, M.A. Shah, M. Shoaib, M. Waqas \cmsinstskip**AGH University of Science and Technology Faculty of Computer Science, Electronics and Telecommunications, Krakow, Poland

** V. Avati, L. Grzanka, M. Malawski \cmsinstskip**National Centre for Nuclear Research, Swierk, Poland

** H. Bialkowska, M. Bluj, B. Boimska, M. Górski, M. Kazana, M. Szleper, P. Zalewski \cmsinstskip**Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Warsaw, Poland

** K. Bunkowski, A. Byszuk\cmsAuthorMark35, K. Doroba, A. Kalinowski, M. Konecki, J. Krolikowski, M. Misiura, M. Olszewski, A. Pyskir, M. Walczak \cmsinstskip**Laboratório de Instrumentação e Física Experimental de Partículas, Lisboa, Portugal

** M. Araujo, P. Bargassa, D. Bastos, A. Di Francesco, P. Faccioli, B. Galinhas, M. Gallinaro, J. Hollar, N. Leonardo, J. Seixas, K. Shchelina, G. Strong, O. Toldaiev, J. Varela \cmsinstskip**Joint Institute for Nuclear Research, Dubna, Russia

** S. Afanasiev, P. Bunin, M. Gavrilenko, I. Golutvin, I. Gorbunov, A. Kamenev, V. Karjavine, A. Lanev, A. Malakhov, V. Matveev\cmsAuthorMark36*,*\cmsAuthorMark37, P. Moisenz, V. Palichik, V. Perelygin, M. Savina, S. Shmatov, S. Shulha, N. Skatchkov, V. Smirnov, N. Voytishin, A. Zarubin \cmsinstskip**Petersburg Nuclear Physics Institute, Gatchina (St. Petersburg), Russia

** L. Chtchipounov, V. Golovtsov, Y. Ivanov, V. Kim\cmsAuthorMark38, E. Kuznetsova\cmsAuthorMark39, P. Levchenko, V. Murzin, V. Oreshkin, I. Smirnov, D. Sosnov, V. Sulimov, L. Uvarov, A. Vorobyev \cmsinstskip**Institute for Nuclear Research, Moscow, Russia

** Yu. Andreev, A. Dermenev, S. Gninenko, N. Golubev, A. Karneyeu, M. Kirsanov, N. Krasnikov, A. Pashenkov, D. Tlisov, A. Toropin \cmsinstskip**Institute for Theoretical and Experimental Physics named by A.I. Alikhanov of NRC ‘Kurchatov Institute’, Moscow, Russia

** V. Epshteyn, V. Gavrilov, N. Lychkovskaya, A. Nikitenko\cmsAuthorMark40, V. Popov, I. Pozdnyakov, G. Safronov, A. Spiridonov, A. Stepennov, M. Toms, E. Vlasov, A. Zhokin \cmsinstskip**Moscow Institute of Physics and Technology, Moscow, Russia

** T. Aushev \cmsinstskip**National Research Nuclear University ’Moscow Engineering Physics Institute’ (MEPhI), Moscow, Russia

** O. Bychkova, R. Chistov\cmsAuthorMark41, M. Danilov\cmsAuthorMark41, S. Polikarpov\cmsAuthorMark41, E. Tarkovskii \cmsinstskip**P.N. Lebedev Physical Institute, Moscow, Russia

** V. Andreev, M. Azarkin, I. Dremin, M. Kirakosyan, A. Terkulov \cmsinstskip**Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University, Moscow, Russia

** A. Baskakov, A. Belyaev, E. Boos, V. Bunichev, M. Dubinin\cmsAuthorMark42, L. Dudko, V. Klyukhin, N. Korneeva, I. Lokhtin, S. Obraztsov, M. Perfilov, V. Savrin, P. Volkov \cmsinstskip**Novosibirsk State University (NSU), Novosibirsk, Russia

** A. Barnyakov\cmsAuthorMark43, V. Blinov\cmsAuthorMark43, T. Dimova\cmsAuthorMark43, L. Kardapoltsev\cmsAuthorMark43, Y. Skovpen\cmsAuthorMark43 \cmsinstskip**Institute for High Energy Physics of National Research Centre ‘Kurchatov Institute’, Protvino, Russia

** I. Azhgirey, I. Bayshev, S. Bitioukov, V. Kachanov, D. Konstantinov, P. Mandrik, V. Petrov, R. Ryutin, S. Slabospitskii, A. Sobol, S. Troshin, N. Tyurin, A. Uzunian, A. Volkov \cmsinstskip**National Research Tomsk Polytechnic University, Tomsk, Russia

** A. Babaev, A. Iuzhakov, V. Okhotnikov \cmsinstskip**Tomsk State University, Tomsk, Russia

** V. Borchsh, V. Ivanchenko, E. Tcherniaev \cmsinstskip**University of Belgrade: Faculty of Physics and VINCA Institute of Nuclear Sciences

** P. Adzic\cmsAuthorMark44, P. Cirkovic, D. Devetak, M. Dordevic, P. Milenovic, J. Milosevic, M. Stojanovic \cmsinstskip**Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Madrid, Spain

** M. Aguilar-Benitez, J. Alcaraz Maestre, A. Álvarez Fernández, I. Bachiller, M. Barrio Luna, J.A. Brochero Cifuentes, C.A. Carrillo Montoya, M. Cepeda, M. Cerrada, N. Colino, B. De La Cruz, A. Delgado Peris, C. Fernandez Bedoya, J.P. Fernández Ramos, J. Flix, M.C. Fouz, O. Gonzalez Lopez, S. Goy Lopez, J.M. Hernandez, M.I. Josa, D. Moran, Á. Navarro Tobar, A. Pérez-Calero Yzquierdo, J. Puerta Pelayo, I. Redondo, L. Romero, S. Sánchez Navas, M.S. Soares, A. Triossi, C. Willmott \cmsinstskip**Universidad Autónoma de Madrid, Madrid, Spain

** C. Albajar, J.F. de Trocóniz \cmsinstskip**Universidad de Oviedo, Instituto Universitario de Ciencias y Tecnologías Espaciales de Asturias (ICTEA), Oviedo, Spain

** B. Alvarez Gonzalez, J. Cuevas, C. Erice, J. Fernandez Menendez, S. Folgueras, I. Gonzalez Caballero, J.R. González Fernández, E. Palencia Cortezon, V. Rodríguez Bouza, S. Sanchez Cruz \cmsinstskip**Instituto de Física de Cantabria (IFCA), CSIC-Universidad de Cantabria, Santander, Spain

** I.J. Cabrillo, A. Calderon, B. Chazin Quero, J. Duarte Campderros, M. Fernandez, P.J. Fernández Manteca, A. García Alonso, G. Gomez, C. Martinez Rivero, P. Martinez Ruiz del Arbol, F. Matorras, J. Piedra Gomez, C. Prieels, T. Rodrigo, A. Ruiz-Jimeno, L. Russo\cmsAuthorMark45, L. Scodellaro, N. Trevisani, I. Vila, J.M. Vizan Garcia \cmsinstskip**University of Colombo, Colombo, Sri Lanka

** K. Malagalage \cmsinstskip**University of Ruhuna, Department of Physics, Matara, Sri Lanka

** W.G.D. Dharmaratna, N. Wickramage \cmsinstskip**CERN, European Organization for Nuclear Research, Geneva, Switzerland

** D. Abbaneo, B. Akgun, E. Auffray, G. Auzinger, J. Baechler, P. Baillon, A.H. Ball, D. Barney, J. Bendavid, M. Bianco, A. Bocci, E. Bossini, C. Botta, E. Brondolin, T. Camporesi, A. Caratelli, G. Cerminara, E. Chapon, G. Cucciati, D. d’Enterria, A. Dabrowski, N. Daci, V. Daponte, A. David, O. Davignon, A. De Roeck, N. Deelen, M. Deile, M. Dobson, M. Dünser, N. Dupont, A. Elliott-Peisert, F. Fallavollita\cmsAuthorMark46, D. Fasanella, G. Franzoni, J. Fulcher, W. Funk, S. Giani, D. Gigi, A. Gilbert, K. Gill, F. Glege, M. Gruchala, M. Guilbaud, D. Gulhan, J. Hegeman, C. Heidegger, Y. Iiyama, V. Innocente, P. Janot, O. Karacheban\cmsAuthorMark20, J. Kaspar, J. Kieseler, M. Krammer\cmsAuthorMark1, C. Lange, P. Lecoq, C. Lourenço, L. Malgeri, M. Mannelli, A. Massironi, F. Meijers, J.A. Merlin, S. Mersi, E. Meschi, F. Moortgat, M. Mulders, J. Ngadiuba, S. Nourbakhsh, S. Orfanelli, L. Orsini, F. Pantaleo\cmsAuthorMark17, L. Pape, E. Perez, M. Peruzzi, A. Petrilli, G. Petrucciani, A. Pfeiffer, M. Pierini, F.M. Pitters, D. Rabady, A. Racz, M. Rovere, H. Sakulin, C. Schäfer, C. Schwick, M. Selvaggi, A. Sharma, P. Silva, W. Snoeys, P. Sphicas\cmsAuthorMark47, J. Steggemann, V.R. Tavolaro, D. Treille, A. Tsirou, A. Vartak, M. Verzetti, W.D. Zeuner \cmsinstskip**Paul Scherrer Institut, Villigen, Switzerland

** L. Caminada\cmsAuthorMark48, K. Deiters, W. Erdmann, R. Horisberger, Q. Ingram, H.C. Kaestli, D. Kotlinski, U. Langenegger, T. Rohe, S.A. Wiederkehr \cmsinstskip**ETH Zurich - Institute for Particle Physics and Astrophysics (IPA), Zurich, Switzerland

** M. Backhaus, P. Berger, N. Chernyavskaya, G. Dissertori, M. Dittmar, M. Donegà, C. Dorfer, T.A. Gómez Espinosa, C. Grab, D. Hits, T. Klijnsma, W. Lustermann, R.A. Manzoni, M. Marionneau, M.T. Meinhard, F. Micheli, P. Musella, F. Nessi-Tedaldi, F. Pauss, G. Perrin, L. Perrozzi, S. Pigazzini, M. Reichmann, C. Reissel, T. Reitenspiess, D. Ruini, D.A. Sanz Becerra, M. Schönenberger, L. Shchutska, M.L. Vesterbacka Olsson, R. Wallny, D.H. Zhu \cmsinstskip**Universität Zürich, Zurich, Switzerland

** T.K. Aarrestad, C. Amsler\cmsAuthorMark49, D. Brzhechko, M.F. Canelli, A. De Cosa, R. Del Burgo, S. Donato, B. Kilminster, S. Leontsinis, V.M. Mikuni, I. Neutelings, G. Rauco, P. Robmann, D. Salerno, K. Schweiger, C. Seitz, Y. Takahashi, S. Wertz, A. Zucchetta \cmsinstskip**National Central University, Chung-Li, Taiwan

** T.H. Doan, C.M. Kuo, W. Lin, S.S. Yu \cmsinstskip**National Taiwan University (NTU), Taipei, Taiwan

** P. Chang, Y. Chao, K.F. Chen, P.H. Chen, W.-S. Hou, Y.y. Li, R.-S. Lu, E. Paganis, A. Psallidas, A. Steen \cmsinstskip**Chulalongkorn University, Faculty of Science, Department of Physics, Bangkok, Thailand

** B. Asavapibhop, C. Asawatangtrakuldee, N. Srimanobhas, N. Suwonjandee, V. Wachirapusitanand \cmsinstskip**Çukurova University, Physics Department, Science and Art Faculty, Adana, Turkey

** A. Bat, F. Boran, S. Damarseckin\cmsAuthorMark50, Z.S. Demiroglu, F. Dolek, C. Dozen, I. Dumanoglu, E. Eskut, G. Gokbulut, EmineGurpinar Guler\cmsAuthorMark51, Y. Guler, I. Hos\cmsAuthorMark52, C. Isik, E.E. Kangal\cmsAuthorMark53, O. Kara, A. Kayis Topaksu, U. Kiminsu, M. Oglakci, G. Onengut, K. Ozdemir\cmsAuthorMark54, A.E. Simsek, D. Sunar Cerci\cmsAuthorMark55, B. Tali\cmsAuthorMark55, U.G. Tok, S. Turkcapar, I.S. Zorbakir, C. Zorbilmez \cmsinstskip**Middle East Technical University, Physics Department, Ankara, Turkey

** B. Isildak\cmsAuthorMark56, G. Karapinar\cmsAuthorMark57, M. Yalvac \cmsinstskip**Bogazici University, Istanbul, Turkey

** I.O. Atakisi, E. Gülmez, O. Kaya\cmsAuthorMark58, B. Kaynak, Ö. Özçelik, S. Ozkorucuklu\cmsAuthorMark59, S. Tekten, E.A. Yetkin\cmsAuthorMark60 \cmsinstskip**Istanbul Technical University, Istanbul, Turkey

** A. Cakir, K. Cankocak, Y. Komurcu, S. Sen\cmsAuthorMark61 \cmsinstskip**Institute for Scintillation Materials of National Academy of Science of Ukraine, Kharkov, Ukraine

** B. Grynyov \cmsinstskip**National Scientific Center, Kharkov Institute of Physics and Technology, Kharkov, Ukraine

** L. Levchuk \cmsinstskip**University of Bristol, Bristol, United Kingdom

** F. Ball, E. Bhal, S. Bologna, J.J. Brooke, D. Burns, E. Clement, D. Cussans, H. Flacher, J. Goldstein, G.P. Heath, H.F. Heath, L. Kreczko, S. Paramesvaran, B. Penning, T. Sakuma, S. Seif El Nasr-Storey, D. Smith, V.J. Smith, J. Taylor, A. Titterton \cmsinstskip**Rutherford Appleton Laboratory, Didcot, United Kingdom

** K.W. Bell, A. Belyaev\cmsAuthorMark62, C. Brew, R.M. Brown, D. Cieri, D.J.A. Cockerill, J.A. Coughlan, K. Harder, S. Harper, J. Linacre, K. Manolopoulos, D.M. Newbold, E. Olaiya, D. Petyt, T. Reis, T. Schuh, C.H. Shepherd-Themistocleous, A. Thea, I.R. Tomalin, T. Williams, W.J. Womersley \cmsinstskip**Imperial College, London, United Kingdom

** R. Bainbridge, P. Bloch, J. Borg, S. Breeze, O. Buchmuller, A. Bundock, GurpreetSingh CHAHAL\cmsAuthorMark63, D. Colling, P. Dauncey, G. Davies, M. Della Negra, R. Di Maria, P. Everaerts, G. Hall, G. Iles, T. James, M. Komm, C. Laner, L. Lyons, A.-M. Magnan, S. Malik, A. Martelli, V. Milosevic, J. Nash\cmsAuthorMark64, V. Palladino, M. Pesaresi, D.M. Raymond, A. Richards, A. Rose, E. Scott, C. Seez, A. Shtipliyski, M. Stoye, T. Strebler, S. Summers, A. Tapper, K. Uchida, T. Virdee\cmsAuthorMark17, N. Wardle, D. Winterbottom, J. Wright, A.G. Zecchinelli, S.C. Zenz \cmsinstskip**Brunel University, Uxbridge, United Kingdom

** J.E. Cole, P.R. Hobson, A. Khan, P. Kyberd, C.K. Mackay, A. Morton, I.D. Reid, L. Teodorescu, S. Zahid \cmsinstskip**Baylor University, Waco, USA

** K. Call, J. Dittmann, K. Hatakeyama, C. Madrid, B. McMaster, N. Pastika, C. Smith \cmsinstskip**Catholic University of America, Washington, DC, USA

** R. Bartek, A. Dominguez, R. Uniyal \cmsinstskip**The University of Alabama, Tuscaloosa, USA

** A. Buccilli, S.I. Cooper, C. Henderson, P. Rumerio, C. West \cmsinstskip**Boston University, Boston, USA

** D. Arcaro, T. Bose, Z. Demiragli, D. Gastler, S. Girgis, D. Pinna, C. Richardson, J. Rohlf, D. Sperka, I. Suarez, L. Sulak, D. Zou \cmsinstskip**Brown University, Providence, USA

** G. Benelli, B. Burkle, X. Coubez, D. Cutts, Y.t. Duh, M. Hadley, J. Hakala, U. Heintz, J.M. Hogan\cmsAuthorMark65, K.H.M. Kwok, E. Laird, G. Landsberg, J. Lee, Z. Mao, M. Narain, S. Sagir\cmsAuthorMark66, R. Syarif, E. Usai, D. Yu \cmsinstskip**University of California, Davis, Davis, USA

** R. Band, C. Brainerd, R. Breedon, M. Calderon De La Barca Sanchez, M. Chertok, J. Conway, R. Conway, P.T. Cox, R. Erbacher, C. Flores, G. Funk, F. Jensen, W. Ko, O. Kukral, R. Lander, M. Mulhearn, D. Pellett, J. Pilot, M. Shi, D. Stolp, D. Taylor, K. Tos, M. Tripathi, Z. Wang, F. Zhang \cmsinstskip**University of California, Los Angeles, USA

** M. Bachtis, C. Bravo, R. Cousins, A. Dasgupta, A. Florent, J. Hauser, M. Ignatenko, N. Mccoll, W.A. Nash, S. Regnard, D. Saltzberg, C. Schnaible, B. Stone, V. Valuev \cmsinstskip**University of California, Riverside, Riverside, USA

** K. Burt, R. Clare, J.W. Gary, S.M.A. Ghiasi Shirazi, G. Hanson, G. Karapostoli, E. Kennedy, O.R. Long, M. Olmedo Negrete, M.I. Paneva, W. Si, L. Wang, H. Wei, S. Wimpenny, B.R. Yates, Y. Zhang \cmsinstskip**University of California, San Diego, La Jolla, USA

** J.G. Branson, P. Chang, S. Cittolin, M. Derdzinski, R. Gerosa, D. Gilbert, B. Hashemi, D. Klein, V. Krutelyov, J. Letts, M. Masciovecchio, S. May, S. Padhi, M. Pieri, V. Sharma, M. Tadel, F. Würthwein, A. Yagil, G. Zevi Della Porta \cmsinstskip**University of California, Santa Barbara - Department of Physics, Santa Barbara, USA

** N. Amin, R. Bhandari, C. Campagnari, M. Citron, V. Dutta, M. Franco Sevilla, L. Gouskos, J. Incandela, B. Marsh, H. Mei, A. Ovcharova, H. Qu, J. Richman, U. Sarica, D. Stuart, S. Wang, J. Yoo \cmsinstskip**California Institute of Technology, Pasadena, USA

** D. Anderson, A. Bornheim, O. Cerri, I. Dutta, J.M. Lawhorn, N. Lu, J. Mao, H.B. Newman, T.Q. Nguyen, J. Pata, M. Spiropulu, J.R. Vlimant, C. Wang, S. Xie, Z. Zhang, R.Y. Zhu \cmsinstskip**Carnegie Mellon University, Pittsburgh, USA

** M.B. Andrews, T. Ferguson, T. Mudholkar, M. Paulini, M. Sun, I. Vorobiev, M. Weinberg \cmsinstskip**University of Colorado Boulder, Boulder, USA

** J.P. Cumalat, W.T. Ford, A. Johnson, E. MacDonald, T. Mulholland, R. Patel, A. Perloff, K. Stenson, K.A. Ulmer, S.R. Wagner \cmsinstskip**Cornell University, Ithaca, USA

** J. Alexander, J. Chaves, Y. Cheng, J. Chu, A. Datta, A. Frankenthal, K. Mcdermott, N. Mirman, J.R. Patterson, D. Quach, A. Rinkevicius\cmsAuthorMark67, A. Ryd, S.M. Tan, Z. Tao, J. Thom, P. Wittich, M. Zientek \cmsinstskip**Fermi National Accelerator Laboratory, Batavia, USA

** S. Abdullin, M. Albrow, M. Alyari, G. Apollinari, A. Apresyan, A. Apyan, S. Banerjee, L.A.T. Bauerdick, A. Beretvas, J. Berryhill, P.C. Bhat, K. Burkett, J.N. Butler, A. Canepa, G.B. Cerati, H.W.K. Cheung, F. Chlebana, M. Cremonesi, J. Duarte, V.D. Elvira, J. Freeman, Z. Gecse, E. Gottschalk, L. Gray, D. Green, S. Grünendahl, O. Gutsche, AllisonReinsvold Hall, J. Hanlon, R.M. Harris, S. Hasegawa, R. Heller, J. Hirschauer, B. Jayatilaka, S. Jindariani, M. Johnson, U. Joshi, B. Klima, M.J. Kortelainen, B. Kreis, S. Lammel, J. Lewis, D. Lincoln, R. Lipton, M. Liu, T. Liu, J. Lykken, K. Maeshima, J.M. Marraffino, D. Mason, P. McBride, P. Merkel, S. Mrenna, S. Nahn, V. O’Dell, V. Papadimitriou, K. Pedro, C. Pena, G. Rakness, F. Ravera, L. Ristori, B. Schneider, E. Sexton-Kennedy, N. Smith, A. Soha, W.J. Spalding, L. Spiegel, S. Stoynev, J. Strait, N. Strobbe, L. Taylor, S. Tkaczyk, N.V. Tran, L. Uplegger, E.W. Vaandering, C. Vernieri, M. Verzocchi, R. Vidal, M. Wang, H.A. Weber \cmsinstskip**University of Florida, Gainesville, USA

** D. Acosta, P. Avery, P. Bortignon, D. Bourilkov, A. Brinkerhoff, L. Cadamuro, A. Carnes, V. Cherepanov, D. Curry, F. Errico, R.D. Field, S.V. Gleyzer, B.M. Joshi, M. Kim, J. Konigsberg, A. Korytov, K.H. Lo, P. Ma, K. Matchev, N. Menendez, G. Mitselmakher, D. Rosenzweig, K. Shi, J. Wang, S. Wang, X. Zuo \cmsinstskip**Florida International University, Miami, USA

** Y.R. Joshi \cmsinstskip**Florida State University, Tallahassee, USA

** T. Adams, A. Askew, S. Hagopian, V. Hagopian, K.F. Johnson, R. Khurana, T. Kolberg, G. Martinez, T. Perry, H. Prosper, C. Schiber, R. Yohay, J. Zhang \cmsinstskip**Florida Institute of Technology, Melbourne, USA

** M.M. Baarmand, V. Bhopatkar, M. Hohlmann, D. Noonan, M. Rahmani, M. Saunders, F. Yumiceva \cmsinstskip**University of Illinois at Chicago (UIC), Chicago, USA

** M.R. Adams, L. Apanasevich, D. Berry, R.R. Betts, R. Cavanaugh, X. Chen, S. Dittmer, O. Evdokimov, C.E. Gerber, D.A. Hangal, D.J. Hofman, K. Jung, C. Mills, T. Roy, M.B. Tonjes, N. Varelas, H. Wang, X. Wang, Z. Wu \cmsinstskip**The University of Iowa, Iowa City, USA

** M. Alhusseini, B. Bilki\cmsAuthorMark51, W. Clarida, K. Dilsiz\cmsAuthorMark68, S. Durgut, R.P. Gandrajula, M. Haytmyradov, V. Khristenko, O.K. Köseyan, J.-P. Merlo, A. Mestvirishvili\cmsAuthorMark69, A. Moeller, J. Nachtman, H. Ogul\cmsAuthorMark70, Y. Onel, F. Ozok\cmsAuthorMark71, A. Penzo, C. Snyder, E. Tiras, J. Wetzel \cmsinstskip**Johns Hopkins University, Baltimore, USA

** B. Blumenfeld, A. Cocoros, N. Eminizer, D. Fehling, L. Feng, A.V. Gritsan, W.T. Hung, P. Maksimovic, J. Roskes, M. Swartz, M. Xiao \cmsinstskip**The University of Kansas, Lawrence, USA

** C. Baldenegro Barrera, P. Baringer, A. Bean, S. Boren, J. Bowen, A. Bylinkin, T. Isidori, S. Khalil, J. King, G. Krintiras, A. Kropivnitskaya, C. Lindsey, D. Majumder, W. Mcbrayer, N. Minafra, M. Murray, C. Rogan, C. Royon, S. Sanders, E. Schmitz, J.D. Tapia Takaki, Q. Wang, J. Williams, G. Wilson \cmsinstskip**Kansas State University, Manhattan, USA

** S. Duric, A. Ivanov, K. Kaadze, D. Kim, Y. Maravin, D.R. Mendis, T. Mitchell, A. Modak, A. Mohammadi \cmsinstskip**Lawrence Livermore National Laboratory, Livermore, USA

** F. Rebassoo, D. Wright \cmsinstskip**University of Maryland, College Park, USA

** A. Baden, O. Baron, A. Belloni, S.C. Eno, Y. Feng, N.J. Hadley, S. Jabeen, G.Y. Jeng, R.G. Kellogg, J. Kunkle, A.C. Mignerey, S. Nabili, F. Ricci-Tam, M. Seidel, Y.H. Shin, A. Skuja, S.C. Tonwar, K. Wong \cmsinstskip**Massachusetts Institute of Technology, Cambridge, USA

** D. Abercrombie, B. Allen, A. Baty, R. Bi, S. Brandt, W. Busza, I.A. Cali, M. D’Alfonso, G. Gomez Ceballos, M. Goncharov, P. Harris, D. Hsu, M. Hu, M. Klute, D. Kovalskyi, Y.-J. Lee, P.D. Luckey, B. Maier, A.C. Marini, C. Mcginn, C. Mironov, S. Narayanan, X. Niu, C. Paus, D. Rankin, C. Roland, G. Roland, Z. Shi, G.S.F. Stephans, K. Sumorok, K. Tatar, D. Velicanu, J. Wang, T.W. Wang, B. Wyslouch \cmsinstskip**University of Minnesota, Minneapolis, USA

** A.C. Benvenuti${}^{\textrm{\textdagger}}$, R.M. Chatterjee, A. Evans, S. Guts, P. Hansen, J. Hiltbrand, Sh. Jain, S. Kalafut, Y. Kubota, Z. Lesko, J. Mans, R. Rusack, M.A. Wadud \cmsinstskip**University of Mississippi, Oxford, USA

** J.G. Acosta, S. Oliveros \cmsinstskip**University of Nebraska-Lincoln, Lincoln, USA

** K. Bloom, D.R. Claes, C. Fangmeier, L. Finco, F. Golf, R. Gonzalez Suarez, R. Kamalieddin, I. Kravchenko, J.E. Siado, G.R. Snow, B. Stieger \cmsinstskip**State University of New York at Buffalo, Buffalo, USA

** G. Agarwal, C. Harrington, I. Iashvili, A. Kharchilava, C. Mclean, D. Nguyen, A. Parker, J. Pekkanen, S. Rappoccio, B. Roozbahani \cmsinstskip**Northeastern University, Boston, USA

** G. Alverson, E. Barberis, C. Freer, Y. Haddad, A. Hortiangtham, G. Madigan, D.M. Morse, T. Orimoto, L. Skinnari, A. Tishelman-Charny, T. Wamorkar, B. Wang, A. Wisecarver, D. Wood \cmsinstskip**Northwestern University, Evanston, USA

** S. Bhattacharya, J. Bueghly, T. Gunter, K.A. Hahn, N. Odell, M.H. Schmitt, K. Sung, M. Trovato, M. Velasco \cmsinstskip**University of Notre Dame, Notre Dame, USA

** R. Bucci, N. Dev, R. Goldouzian, M. Hildreth, K. Hurtado Anampa, C. Jessop, D.J. Karmgard, K. Lannon, W. Li, N. Loukas, N. Marinelli, I. Mcalister, F. Meng, C. Mueller, Y. Musienko\cmsAuthorMark36, M. Planer, R. Ruchti, P. Siddireddy, G. Smith, S. Taroni, M. Wayne, A. Wightman, M. Wolf, A. Woodard \cmsinstskip**The Ohio State University, Columbus, USA

** J. Alimena, B. Bylsma, L.S. Durkin, S. Flowers, B. Francis, C. Hill, W. Ji, A. Lefeld, T.Y. Ling, B.L. Winer \cmsinstskip**Princeton University, Princeton, USA

** S. Cooperstein, G. Dezoort, P. Elmer, J. Hardenbrook, N. Haubrich, S. Higginbotham, A. Kalogeropoulos, S. Kwan, D. Lange, M.T. Lucchini, J. Luo, D. Marlow, K. Mei, I. Ojalvo, J. Olsen, C. Palmer, P. Piroué, J. Salfeld-Nebgen, D. Stickland, C. Tully, Z. Wang \cmsinstskip**University of Puerto Rico, Mayaguez, USA

** S. Malik, S. Norberg \cmsinstskip**Purdue University, West Lafayette, USA

** A. Barker, V.E. Barnes, S. Das, L. Gutay, M. Jones, A.W. Jung, A. Khatiwada, B. Mahakud, D.H. Miller, G. Negro, N. Neumeister, C.C. Peng, S. Piperov, H. Qiu, J.F. Schulte, J. Sun, F. Wang, R. Xiao, W. Xie \cmsinstskip**Purdue University Northwest, Hammond, USA

** T. Cheng, J. Dolen, N. Parashar \cmsinstskip**Rice University, Houston, USA

** K.M. Ecklund, S. Freed, F.J.M. Geurts, M. Kilpatrick, Arun Kumar, W. Li, B.P. Padley, R. Redjimi, J. Roberts, J. Rorie, W. Shi, A.G. Stahl Leiton, Z. Tu, A. Zhang \cmsinstskip**University of Rochester, Rochester, USA

** A. Bodek, P. de Barbaro, R. Demina, J.L. Dulemba, C. Fallon, T. Ferbel, M. Galanti, A. Garcia-Bellido, J. Han, O. Hindrichs, A. Khukhunaishvili, E. Ranken, P. Tan, R. Taus \cmsinstskip**Rutgers, The State University of New Jersey, Piscataway, USA

** B. Chiarito, J.P. Chou, A. Gandrakota, Y. Gershtein, E. Halkiadakis, A. Hart, M. Heindl, E. Hughes, S. Kaplan, S. Kyriacou, I. Laflotte, A. Lath, R. Montalvo, K. Nash, M. Osherson, H. Saka, S. Salur, S. Schnetzer, D. Sheffield, S. Somalwar, R. Stone, S. Thomas, P. Thomassen \cmsinstskip**University of Tennessee, Knoxville, USA

** H. Acharya, A.G. Delannoy, J. Heideman, G. Riley, S. Spanier \cmsinstskip**Texas A&M University, College Station, USA

** O. Bouhali\cmsAuthorMark72, A. Celik, M. Dalchenko, M. De Mattia, A. Delgado, S. Dildick, R. Eusebi, J. Gilmore, T. Huang, T. Kamon\cmsAuthorMark73, S. Luo, D. Marley, R. Mueller, D. Overton, L. Perniè, D. Rathjens, A. Safonov \cmsinstskip**Texas Tech University, Lubbock, USA

** N. Akchurin, J. Damgov, F. De Guio, S. Kunori, K. Lamichhane, S.W. Lee, T. Mengke, S. Muthumuni, T. Peltola, S. Undleeb, I. Volobouev, Z. Wang, A. Whitbeck \cmsinstskip**Vanderbilt University, Nashville, USA

** S. Greene, A. Gurrola, R. Janjam, W. Johns, C. Maguire, A. Melo, H. Ni, K. Padeken, F. Romeo, P. Sheldon, S. Tuo, J. Velkovska, M. Verweij \cmsinstskip**University of Virginia, Charlottesville, USA

** M.W. Arenton, P. Barria, B. Cox, G. Cummings, R. Hirosky, M. Joyce, A. Ledovskoy, C. Neu, B. Tannenwald, Y. Wang, E. Wolfe, F. Xia \cmsinstskip**Wayne State University, Detroit, USA

** R. Harr, P.E. Karchin, N. Poudyal, J. Sturdy, P. Thapa, S. Zaleski \cmsinstskip**University of Wisconsin - Madison, Madison, WI, USA

** J. Buchanan, C. Caillol, D. Carlsmith, S. Dasu, I. De Bruyn, L. Dodd, F. Fiori, C. Galloni, B. Gomber\cmsAuthorMark74, M. Herndon, A. Hervé, U. Hussain, P. Klabbers, A. Lanaro, A. Loeliger, K. Long, R. Loveless, J. Madhusudanan Sreekala, T. Ruggles, A. Savin, V. Sharma, W.H. Smith, D. Teague, S. Trembath-reichert, N. Woods \cmsinstskip†: Deceased

1: Also at Vienna University of Technology, Vienna, Austria

2: Also at IRFU, CEA, Université Paris-Saclay, Gif-sur-Yvette, France

3: Also at Universidade Estadual de Campinas, Campinas, Brazil

4: Also at Federal University of Rio Grande do Sul, Porto Alegre, Brazil

5: Also at UFMS, Nova Andradina, Brazil

6: Also at Universidade Federal de Pelotas, Pelotas, Brazil

7: Also at Université Libre de Bruxelles, Bruxelles, Belgium

8: Also at University of Chinese Academy of Sciences, Beijing, China

9: Also at Institute for Theoretical and Experimental Physics named by A.I. Alikhanov of NRC ‘Kurchatov Institute’, Moscow, Russia

10: Also at Joint Institute for Nuclear Research, Dubna, Russia

11: Also at Cairo University, Cairo, Egypt

12: Also at Helwan University, Cairo, Egypt

13: Now at Zewail City of Science and Technology, Zewail, Egypt

14: Also at Purdue University, West Lafayette, USA

15: Also at Université de Haute Alsace, Mulhouse, France

16: Also at Erzincan Binali Yildirim University, Erzincan, Turkey

17: Also at CERN, European Organization for Nuclear Research, Geneva, Switzerland

18: Also at RWTH Aachen University, III. Physikalisches Institut A, Aachen, Germany

19: Also at University of Hamburg, Hamburg, Germany

20: Also at Brandenburg University of Technology, Cottbus, Germany

21: Also at Institute of Physics, University of Debrecen, Debrecen, Hungary, Debrecen, Hungary

22: Also at Institute of Nuclear Research ATOMKI, Debrecen, Hungary

23: Also at MTA-ELTE Lendület CMS Particle and Nuclear Physics Group, Eötvös Loránd University, Budapest, Hungary, Budapest, Hungary

24: Also at IIT Bhubaneswar, Bhubaneswar, India, Bhubaneswar, India

25: Also at Institute of Physics, Bhubaneswar, India

26: Also at Shoolini University, Solan, India

27: Also at University of Visva-Bharati, Santiniketan, India

28: Also at Isfahan University of Technology, Isfahan, Iran

29: Also at Italian National Agency for New Technologies, Energy and Sustainable Economic Development, Bologna, Italy

30: Also at Centro Siciliano di Fisica Nucleare e di Struttura Della Materia, Catania, Italy

31: Also at Scuola Normale e Sezione dell’INFN, Pisa, Italy

32: Also at Riga Technical University, Riga, Latvia, Riga, Latvia

33: Also at Malaysian Nuclear Agency, MOSTI, Kajang, Malaysia

34: Also at Consejo Nacional de Ciencia y Tecnología, Mexico City, Mexico

35: Also at Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland

36: Also at Institute for Nuclear Research, Moscow, Russia

37: Now at National Research Nuclear University ’Moscow Engineering Physics Institute’ (MEPhI), Moscow, Russia

38: Also at St. Petersburg State Polytechnical University, St. Petersburg, Russia

39: Also at University of Florida, Gainesville, USA

40: Also at Imperial College, London, United Kingdom

41: Also at P.N. Lebedev Physical Institute, Moscow, Russia

42: Also at California Institute of Technology, Pasadena, USA

43: Also at Budker Institute of Nuclear Physics, Novosibirsk, Russia

44: Also at Faculty of Physics, University of Belgrade, Belgrade, Serbia

45: Also at Università degli Studi di Siena, Siena, Italy

46: Also at INFN Sezione di Pavia a, Università di Pavia b, Pavia, Italy, Pavia, Italy

47: Also at National and Kapodistrian University of Athens, Athens, Greece

48: Also at Universität Zürich, Zurich, Switzerland

49: Also at Stefan Meyer Institute for Subatomic Physics, Vienna, Austria, Vienna, Austria

50: Also at Şırnak University, Sirnak, Turkey

51: Also at Beykent University, Istanbul, Turkey, Istanbul, Turkey

52: Also at Istanbul Aydin University, Istanbul, Turkey

53: Also at Mersin University, Mersin, Turkey

54: Also at Piri Reis University, Istanbul, Turkey

55: Also at Adiyaman University, Adiyaman, Turkey

56: Also at Ozyegin University, Istanbul, Turkey

57: Also at Izmir Institute of Technology, Izmir, Turkey

58: Also at Kafkas University, Kars, Turkey

59: Also at Istanbul University, Istanbul, Turkey

60: Also at Istanbul Bilgi University, Istanbul, Turkey

61: Also at Hacettepe University, Ankara, Turkey

62: Also at School of Physics and Astronomy, University of Southampton, Southampton, United Kingdom

63: Also at IPPP Durham University, Durham, United Kingdom

64: Also at Monash University, Faculty of Science, Clayton, Australia

65: Also at Bethel University, St. Paul, Minneapolis, USA, St. Paul, USA

66: Also at Karamanoğlu Mehmetbey University, Karaman, Turkey

67: Also at Vilnius University, Vilnius, Lithuania

68: Also at Bingol University, Bingol, Turkey

69: Also at Georgian Technical University, Tbilisi, Georgia

70: Also at Sinop University, Sinop, Turkey

71: Also at Mimar Sinan University, Istanbul, Istanbul, Turkey

72: Also at Texas A&M University at Qatar, Doha, Qatar

73: Also at Kyungpook National University, Daegu, Korea, Daegu, Korea

74: Also at University of Hyderabad, Hyderabad, India