Search for dark photons in decays of Higgs bosons produced in association with Z bosons in proton-proton collisions at $\sqrt{s} =$ 13 TeV

TL;DR

This paper searches for Higgs boson decays involving an undetected massless dark photon produced alongside a Z boson in proton-proton collisions at 13 TeV, setting the first limits on such decay modes.

Contribution

It introduces the first experimental limits on Higgs decays to final states with an undetected massless dark photon using CMS data at 13 TeV.

Findings

No significant excess observed over standard model background.

Upper limit of 4.6% on Higgs to dark photon decay branching fraction at 125 GeV.

First constraints on Higgs decays involving a massless dark photon.

Abstract

A search is presented for a Higgs boson that is produced in association with a Z boson and that decays to an undetected particle together with an isolated photon. The search is performed by the CMS Collaboration at the Large Hadron Collider using a data set corresponding to an integrated luminosity of 137 fb$^{-1}$ recorded at a center-of-mass energy of 13 TeV. No significant excess of events above the expectation from the standard model background is found. The results are interpreted in the context of a theoretical model in which the undetected particle is a massless dark photon. An upper limit is set on the product of the cross section for associated Higgs and Z boson production and the branching fraction for such a Higgs boson decay, as a function of the Higgs boson mass. For a mass of 125 GeV, assuming the standard model production cross section, this corresponds to an observed (expected) upper limit on this branching fraction of 4.6 (3.6)% at 95% confidence level. These are the first limits on Higgs boson decays to final states that include an undetected massless dark photon.

Tables

Table 1. Table 1: Observed yields, background estimates after the fit to data, and signal predictions after the event selection. The signal size corresponds to 0.1 ​ σ \cPZ ​ \PH 0.1 subscript 𝜎 \cPZ \PH 0.1\sigma_{\cPZ\PH} for all three m \PH subscript 𝑚 \PH m_{\PH} values shown. The combined statistical and systematic uncertainties are reported. The values in parentheses for the signal processes correspond to the products of acceptance and selection efficiency for \cPZ → ℓ ​ ℓ → \cPZ ℓ ℓ \cPZ\to\ell\ell events.

Process	Yield
Data	14
Nonresonant	$2.4\pm 1.1$
$\text{PW}\text{cPZ}$	$8.1\pm 2.0$
$\text{cPZ}\text{cPZ}$	$1.5\pm 0.3$
$\text{cPZ}\gamma$	$0.7\pm 0.7$
Other	$0.6\pm 0.3$
Total background	$13.3\pm 3.8$
$\text{cPZ}{\text{PH}}_{125}$ (product of acceptance and efficiency)	$17.9\pm 1.2$ ($2.13\pm 0.14$%)
$\text{cPZ}{\text{PH}}_{200}$ (product of acceptance and efficiency)	$12.3\pm 0.8$ ($6.48\pm 0.42$%)
$\text{cPZ}{\text{PH}}_{300}$ (product of acceptance and efficiency)	$3.9\pm 0.2$ ($10.20\pm 0.51$%)

Equations

$$\begin{split}\mathcal{L}=\prod_{i,j,k}&\mathcal{P}\Big{(}N^{\mathrm{SR}}_{\mathrm{Obs},(i,j,k)}\mid N^{SR}_{\mathrm{Other,(i,j,k)}}(\theta)+\mu N^{SR}_{\cPZ\PH,(i,j,k)}(\theta)+\mu^{\mathrm{Nonres}}N^{SR}_{\mathrm{Nonres,(i,j,k)}}(\theta)\\ &+\mu^{\PW\cPZ}N^{SR}_{\PW\cPZ,(i,j,k)}(\theta)+\mu^{\cPZ\cPZ}N^{SR}_{\cPZ\cPZ,(i,j,k)}(\theta)\Big{)}\\ &\mathcal{P}\Big{(}N^{\Pe\mu}_{\mathrm{Obs},(i,k)}\mid N^{\Pe\mu}_{\mathrm{Other,(i,k)}}(\theta)+\mu^{\mathrm{Nonres}}N^{\Pe\mu}_{\mathrm{Nonres,(i,k)}}(\theta)\Big{)}\\ &\mathcal{P}\Big{(}N^{3\ell}_{\mathrm{Obs},(i,k)}\mid N^{3\ell}_{\mathrm{Other,(i,k)}}(\theta)+\mu^{\PW\cPZ}N^{3\ell}_{\PW\cPZ,(i,k)}(\theta)\Big{)}\\ &\mathcal{P}\Big{(}N^{4\ell}_{\mathrm{Obs},(i,k)}\mid N^{4\ell}_{\mathrm{Other,(i,k)}}(\theta)+\mu^{\cPZ\cPZ}N^{4\ell}_{\cPZ\cPZ,(i,k)}(\theta)\Big{)}\\ &\re^{-(\theta-\hat{\theta})^{2}/2},\\ \end{split}$$

Full text

0.1 Introduction

Following the discovery of a Higgs boson by the ATLAS and CMS Collaborations [1, 2, 3], a primary focus of the LHC physics program has been the study of the properties of the new particle. The observation of a sizable branching fraction of the Higgs boson to invisible or almost invisible final states [4, 5, 6, 7] would be a strong sign of physics beyond the standard model (BSM). Studies of the new boson at a mass of about 125\GeV [8, 9] show no significant deviation from the standard model (SM) Higgs boson hypothesis, and measurements of its couplings constrain its partial decay width to undetected decay modes [10, 11]. Assuming that the couplings of the Higgs boson to $\PW$ and $\cPZ$ bosons are smaller than the SM values, an upper limit of 38% has been obtained at 95% confidence level ($\CL$) on the branching fraction of the 125\GeVHiggs boson to BSM particles [11].

This paper presents a search for a scalar boson $\PH$ produced in association with a $\cPZ$ boson and decaying to an undetected particle together with a photon. Several BSM models predict Higgs boson decays to undetected particles and photons [7, 12, 13]. In this search, the target final state is $\cPZ(\to\ell\ell)\PH(\to\gamma\gamma_{\mathrm{D}})$, where $\ell=\Pe,\mu$, and $\gamma_{\mathrm{D}}$ is a massless dark photon that couples to the Higgs boson through a charged dark sector [14, 15, 16, 17], and is undetected in the CMS detector. The branching fraction to such an invisible particle and a photon, $\mathcal{B}(\PH\to\text{invisible}+\gamma)$, can be as large as 5%, and be consistent with all model parameters and current LHC constraints [15]. A Feynman diagram for such a process is shown in Fig. 1. While the main focus is the case where the production cross section ($\sigma_{\cPZ\PH}$) is assumed to be the same as that for the SM-like Higgs boson with a mass of 125\GeV, the same analysis is also used to search for heavy neutral Higgs bosons with masses between 125 and 300\GeV, since similar decays are also possible for potential non-SM scalar bosons.

In the SM, a similar signature to the signal process arises when the Higgs boson decays via $\PH\to\cPZ\gamma\to\PGn\PAGn\gamma$, which has a branching fraction of $3\times 10^{-4}$. Searches for the decay $\PH\to\cPZ\gamma$ using $\cPZ\to\ell\ell$ final states have yielded an upper limit at 95% $\CL$ on the product of the cross section and branching fraction of about four times the SM expectation [18, 19]. With the available data set, the present search is not sensitive to this SM decay, but because of enhancements that may arise from BSM physics, the search may be sensitive to Higgs boson decays to invisible particles and photons. The analysis summarized in this paper uses proton-proton ($\Pp\Pp$) collision data collected at $\sqrt{s}=13\TeV$ by the CMS detector in 2016–18 with a total integrated luminosity of $137\fbinv$. A similar search was performed by the CMS Collaboration using the data collected at $\sqrt{s}=8\TeV$ [20], although that analysis investigated Higgs bosons produced both in gluon-gluon fusion and in association with a $\cPZ$ boson.

The main backgrounds in this analysis arise from $\PW\cPZ$ and $\cPZ\cPZ$ production, where an electron is mis-identified as a photon, or where additional leptons are not identified because they fail either the lepton identification criteria or the kinematic selections. A second set of backgrounds are due to $\PW\PW$ and top quark production, where the invariant mass of the lepton pair falls into the $\cPZ$ boson mass window. There are also small contributions from other multiboson production processes, such as $\cPZ\gamma$. To enhance the discrimination between the potential signal and the remaining background processes, a binned maximum-likelihood fit to several signal and control regions is performed.

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 (ECAL), and a brass and scintillator hadron calorimeter, each composed of a barrel and two endcap sections. Forward calorimeters extend the pseudorapidity ($\eta$) coverage provided by the barrel and endcap detectors. Muons are detected in gas-ionization chambers embedded in the steel magnetic flux-return yoke outside the solenoid. 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. [21]. Events of interest are selected using a two-tiered trigger system [22]. The first level, composed of custom hardware processors, uses information from the calorimeters and muon detectors to select events, while the second level selects events by running a version of the full event reconstruction software optimized for fast processing on a farm of computer processors.

0.3 Data samples and event reconstruction

The data used in this search were collected in three separate LHC operating periods in 2016, 2017, and 2018. The three data sets are analyzed independently, with appropriate calibrations and corrections to take into account the different LHC running conditions and CMS detector performance.

Monte Carlo (MC) simulated events are used to model the expected signal and background yields. Three sets of simulated events for each process are needed to match the different data taking conditions in the three different years. The next-to-leading-order (NLO) $\POWHEG$ v2 [23, 24, 25, 26, 27] generator is used to simulate the $\cPZ\PH$ signal process at NLO in quantum chromodynamics (QCD), as well as the $\ttbar$, $\PQt\PW$, and diboson processes. The BSM Higgs boson production cross sections as a function of the Higgs boson mass ($m_{\PH}$) for the $\cPZ\PH$ process are taken from Refs. [28, 29]. The signal samples are generated for masses of 125, 200, and 300\GeV. Production of $\ttbar\PW$, $\ttbar\cPZ$, $\ttbar\gamma$, and triple vector boson (\PV\PV\PV) events is generated at NLO in QCD using the $\MGvATNLO$ 2.2.2 (2.4.2) generator for 2016 (2017 and 2018) [30, 31, 32] samples. The NNPDF 3.0 NLO [33] (NNPDF 3.1 next-to-next-to-leading-order [34]) parton distribution functions (PDFs) are used for simulating all 2016 (2017 and 2018) samples. For all processes, the parton showering and hadronization are simulated using $\PYTHIA$ 8.226 (8.230) in 2016 (2017 and 2018) [35]. The modeling of the underlying event is generated using the CUETP8M1 [36, 37] and CP5 tunes [38] for simulated samples corresponding to the 2016 and 2017–18 data sets, respectively.

All MC simulation events are processed through a simulation of the CMS detector based on \GEANTfour [39] and are reconstructed with the same algorithms as used for data. Additional $\Pp\Pp$ interactions in the same and nearby bunch crossings, referred to as pileup, are also simulated. The distribution of the number of such interactions in the simulation is adjusted to match the one observed in the data. The average number of pileup interactions was 23 (32) in 2016 (2017 and 2018).

For this search, collision events were collected using single-electron and single-muon triggers that require the presence of an isolated lepton with transverse momentum ($\pt$) larger than 24 and 27\GeV, respectively. In addition, a set of dilepton triggers with lower $\pt$ thresholds were used, ensuring a trigger efficiency above 99% for events that would satisfy the subsequent offline selection.

Information from all subdetectors is combined and used by the CMS particle-flow (PF) algorithm [40] for particle reconstruction and identification. Jets are reconstructed by clustering PF candidates using the anti-\ktalgorithm [41] with a distance parameter 0.4. Jets are calibrated in the simulation, and separately in data, accounting for energy deposits of neutral particles from pileup and any nonlinear detector response [42]. Jets with $\pt>30\GeV$ and $\abs{\eta}<4.7$ are considered in the analysis. The effect of pileup is mitigated through a charged-hadron subtraction technique, which removes the energy of charged hadrons not originating from the primary interaction vertex (PV) [43]. The PV is defined as the vertex with the largest value of summed physics-object $\pt^{2}$. Here, the physics objects are the jets clustered using the jet finding algorithm [41, 44] with the tracks assigned to the vertex as inputs, and the associated missing transverse momentum, taken as the negative vector $\pt$ sum of those jets.

Events are discarded if they contain a jet with $\pt>20\GeV$ and $\abs{\eta}<2.4$ that is consistent with the fragmentation of a \PQb quark. The combined secondary vertex (CSVv2) \PQb tagging algorithm [45] is used for the 2016 data set, while the DeepCSV algorithm [45] is used for the 2017 and 2018 data sets. For the chosen working points, the efficiency to select \PQb quark jets is about 62 (72)% for CSVv2 (DeepCSV) and the rate for incorrectly \PQb tagging jets originating from the hadronization of gluons or $\cPqu$, $\cPqd$, $\cPqs$ quarks is about 1%.

The vector $\ptvecmiss$ is defined as the negative vector $\pt$ sum of all PF particle candidates. The magnitude of $\ptvecmiss$ is the missing transverse momentum $\ptmiss$. Corrections to jet energies due to detector response are propagated to $\ptmiss$ [46]. Events with possible contributions from beam halo processes or anomalous signals in the calorimeters are rejected using dedicated filters [46].

Electrons and muons are reconstructed by associating a track reconstructed in the tracking detectors with either a cluster of energy in the ECAL [47] or a track in the muon system [48]. Electron and muon candidates must pass certain identification criteria to be further selected in the analysis. For the “loose” identification, they must satisfy $\pt>10\GeV$ and $\abs{\eta}<2.5$ (2.4) for electrons (muons). At the final stage of the lepton selection, the medium working points, following the definitions provided in Ref. [47, 48], are chosen for the identification criteria, including requirements on the impact parameter of the candidates with respect to the PV and their isolation with respect to other particles in the event [49].

Finally, photon candidates are reconstructed from energy deposits in the ECAL [50] within $\abs{\eta}<2.5$. The identification of the candidates is based on shower shape and isolation variables, and the medium working point, as described in Ref. [50], is chosen to select those candidates. In addition, a standard “conversion-safe electron veto” [50] is applied to reject electrons misidentified as photons.

0.4 Event selection

The signal topology consists of two oppositely charged same-flavor high $\pt$ isolated leptons, electrons or muons, compatible with a $\cPZ$ boson decay, large $\ptmiss$, an isolated high $\pt$ photon, and little jet activity. The signal cross section is several orders of magnitude lower than that of the major reducible background processes, and therefore a stringent selection is required to obtain a sample of sufficient purity. To be consistent with the expected topology, the selection requires a leading (subleading) lepton with $\pt>25$ (20)\GeVand at least one photon with transverse momentum $p^{\gamma}_{\mathrm{T}}>25\GeV$. To reduce background processes where the lepton pair is not from the decay of a $\cPZ$ boson, the dilepton mass must be compatible with that of a $\cPZ$ boson within 15\GeVof the pole mass $m_{\cPZ}$ [51]. For the purpose of rejecting the bulk of the $\cPZ\gamma$ background as well as processes with little or moderate boost, a $\ptmiss$ greater than 110\GeVand a transverse momentum of the dilepton system $\pt^{\ell\ell}$ larger than 60\GeVare required.

To reduce the background from $\PW\cPZ$ events with a third lepton from the $\PW$ boson decay, events are removed if, in addition to the two leptons satisfying the full selection criteria, there are any loosely identified leptons. To suppress the top quark background, events are rejected if any jet passes the \cPqb tagging selection (\cPqb jet veto) described above, or if there are more than two identified jets in the event.

The signal topology is characterized by a dilepton system ($\overrightarrow{\ell\ell}$) with large $\pt$ balanced in the transverse plane by the $\ptvecmiss+\vec{p}^{\gamma}_{\mathrm{T}}$ system from the Higgs boson decay. Therefore, to reject most of the background from $\cPZ\gamma$ events with misreconstructed $\ptmiss$, the azimuthal angle between the $\overrightarrow{\ell\ell}$ and $\ptvecmiss+\vec{p}^{\gamma}_{\mathrm{T}}$ systems ($\Delta\phi_{\overrightarrow{\ell\ell},\ptvecmiss+\vec{p}^{\gamma}_{\mathrm{T}}}$) is required to be greater than 2.5 rad, the quantity $\abs{p_{\mathrm{T}}^{\ptvecmiss+\vec{p}^{\gamma}_{\mathrm{T}}}-\pt^{\ell\ell}}/\pt^{\ell\ell}$ is required to be smaller than 0.4, and the azimuthal angle between the leading jet and $\ptvecmiss$ ($\Delta\phi_{\mathrm{jet},\ptvecmiss}$) should be greater than 0.5 rad. In addition, the mass of the dilepton and photon system ($m_{\ell\ell\gamma}$) must be greater than 100\GeVto reject resonant $\cPZ\gamma$ events, where the photon originates from final-state radiation. Finally, the transverse mass of the $\ptvecmiss$ and photon system, defined as $\mT\equiv\sqrt{\smash[b]{2\ptmiss p^{\gamma}_{\mathrm{T}}[1-\cos(\Delta\phi_{\ptvecmiss,\vec{p}^{\gamma}_{\mathrm{T}}})]}}$, must be smaller than 350\GeV, which rejects events where the dilepton and photon objects are weakly correlated, or where the photon momentum is mismeasured. The quantity $\Delta\phi_{\ptvecmiss,\vec{p}^{\gamma}_{\mathrm{T}}}$ is the azimuthal angle between $\ptvecmiss$ and the photon. A summary of the selection for the analysis is shown in Table 0.4.

0.5 Background estimation

A combination of methods based on control samples in data and simulation is used to estimate background contributions. Uncertainties related to the theoretical and experimental predictions are taken into account, as described in Section 0.7. Background contributions are categorized depending on whether they produce at least one lepton pair from the decay of a $\cPZ$ boson (resonant contributions) or no such lepton pair (nonresonant contributions). The expected yield for the irreducible background from $\Pp\Pp\to\cPZ(\to\ell\ell)\PH(\to\cPZ\gamma)\to\ell\ell\PGn\PAGn\gamma$ is less than 0.1 events and is consequently ignored in the analysis.

0.5.1 Nonresonant dilepton backgrounds

The contribution from the nonresonant dilepton backgrounds, mostly $\PW\PW$ and top quark processes, is estimated by exploiting the lepton flavor symmetry in the final states of these processes [52]. A control region based on the $\Pe^{\pm}\mu^{\mp}$ final state, whose branching fraction is twice that of either same flavor lepton pair final state, is used to estimate these backgrounds in the $\Pep\Pem$ and $\PGmp\PGmm$ channels. This region is completely dominated by this nonresonant dilepton background. The method considers the differences between the electron and muon identification efficiencies when extrapolating from the different-flavor to the same-flavor final states. The resulting predictions agree with the number of background events estimated by applying the same method to the simulation. The chosen $\Pe\mu$ control region contains 3 events that satisfy the full analysis selection, to be compared with an expectation of $2.8\pm 0.5\stat$ from the simulation.

0.5.2 Resonant background with genuine missing transverse momentum

The resonant background with genuine missing transverse momentum in which an electron is mis-identified as a photon is dominated by the $\PW\cPZ\to\Pe\PGn\ell\ell$ process. In this case, the background comes from events where the electron from the $\PW$ boson decay is wrongly identified as a photon. The electron to photon misidentification rate is measured in $\cPZ\to\Pe\Pe$ events by comparing the ratio of $\Pe\gamma$ to $\Pe\Pe$ pairs consistent with the $\cPZ$ boson mass, as reconstructed in data and simulation. The average misidentification rate is 1–5%, with the larger values corresponding to higher photon pseudorapidity $\abs{\eta^{\gamma}}$.

Background processes with two leptons and a genuine hard photon are estimated with the simulation. These events arise primarily from the $\PW\cPZ\to\ell\PGn\ell\ell$ process (where the lepton from the $\PW$ boson decay is not identified) and $\cPZ\cPZ\to 2\ell 2\PGn$. In both cases an additional hard photon must be radiated.

To assess the normalization of the $\PW\cPZ\to\ell\PGn\ell\ell$ background, a control region is selected in data by applying the full selection on events where the selected lepton from the $\PW$ boson decay plays the role of the photon. In this region, 231 events are observed in data, while the simulation predicts $241\pm 4\stat$ events.

0.5.3 Resonant background with no genuine missing transverse momentum

The background from $\cPZ\gamma$ or $\cPZ+\text{jets}$ events is predicted by the simulation to be less than 5% of the total background, because of the stringent selection used. One of the data control regions used to verify that the background is correctly estimated selects events with lower $\ptmiss$ than the default selection. Within the uncertainties, good agreement between data and simulation is found. To estimate the overall $\cPZ\cPZ$ normalization, and also to emulate the $\cPZ\gamma$ process, a four-lepton sample is selected in data, and the full analysis selection is performed, with one of the $\cPZ$ boson dilepton pairs as a photon. In this control region, $5.1\pm 0.2\stat$ events are expected from simulation, while 7 events are observed in data.

0.6 Signal extraction

After applying the event selection, the 2016, 2017, and 2018 data sets are treated individually in order to maximize the sensitivity of the combination, since the signal-to-background ratio is different in each case. On the other hand, the electron and muon channels are merged because they show a similar signal-to-background ratio.

To discriminate between the potential signal and the remaining background processes, a binned maximum-likelihood fit to the $\mT$ spectrum is performed. The signal spectrum shows a Jacobian peak with an end-point at $\mT\sim m_{\PH}$, while the background processes have either a flat distribution or display an increase towards lower values of $\mT$. Since the contamination from electrons misidentified as photons is larger at large $\abs{\eta^{\gamma}}$ values, improved sensitivity is achieved by considering separately events with the selected photon at low- or high-$\abs{\eta^{\gamma}}$.

In the maximum-likelihood fit, each bin of the $\mT$ distribution is separated into a low-$\abs{\eta^{\gamma}}$ ($\abs{\eta^{\gamma}}<1$) and a high-$\abs{\eta^{\gamma}}$ ($\abs{\eta^{\gamma}}>1$) bin, for the signal region and the $\Pe\mu$, $\PW\cPZ$, and $\cPZ\cPZ$ control regions. For each individual bin, a Poissonian likelihood term is used to describe the fluctuation of the yields around the expected central value, which is given by the sum of the contributions from signal and background processes. The uncertainties affect the overall normalizations of the signal and background yields, as well as the shapes of the predictions across the distributions of the observables. Correlations between systematic uncertainties in different categories are taken into account. Uncertainties that purely affect the normalization within a category are incorporated as nuisance parameters with log-normal priors, while those associated with changes in shapes are assigned probability density functions described by a polynomial interpolation with a Gaussian constraint. The total likelihood is defined as the product of the likelihoods of the individual bins and the probability density functions for the nuisance parameters, including the product of the likelihood for the individual years. In summary, the maximum-likelihood fit function, $\mathcal{L}$, can be written as:

[TABLE]

where $i$ runs over the three data-taking periods, $j$ runs over the $\mT$ bins, $k$ runs over the two $\abs{\eta^{\gamma}}$ values, $\mathcal{P}(N\mid\lambda)$ is the Poisson probability, $\theta$ are nuisance parameters for the systematic uncertainties, and $\hat{\theta}$ are their default values. The values $N^{\mathrm{SR}}_{\mathrm{Obs},(i,j,k)}$, $N^{\Pe\mu}_{\mathrm{Obs},(i,k)}$, $N^{3\ell}_{\mathrm{Obs},(i,k)}$, and $N^{4\ell}_{\mathrm{Obs},(i,k)}$ are the observed data events in the signal region, and the $\Pe\mu$, $\PW\cPZ$, and $\cPZ\cPZ$ control regions, respectively. The parameters $\mu$, $\mu^{\mathrm{Nonres}}$, $\mu^{\PW\cPZ}$, and $\mu^{\cPZ\cPZ}$ are the fit normalization factors for the signal, nonresonant, $\PW\cPZ$, and $\cPZ\cPZ$ processes, respectively. The values $N_{\cPZ\PH}$, $N_{\mathrm{Nonres}}$, $N_{\PW\cPZ}$, $N_{\cPZ\cPZ}$, and $N_{\mathrm{Other}}$ are the expected number of events for the signal, nonresonant, $\PW$, $\cPZ\cPZ$, and remaining processes, respectively, for the different regions. This approach follows that of Ref. [53], where more details can be found.

The $\mT$ distributions for the $\Pe\mu$, $\PW\cPZ$, and $\cPZ\cPZ$ control regions are shown in Fig. 2. This analysis fits the $\mT$ distributions for two regions of $\abs{\eta^{\gamma}}$, a procedure that improves the expected limits by about 30 to 50% compared with the results from simply counting the contents of a single $\mT$ bin for each $\abs{\eta^{\gamma}}$ region, as was done in Ref. [20]. The improvement from splitting the data into two regions of $\abs{\eta^{\gamma}}$ is about 4%.

0.7 Efficiencies and systematic uncertainties

Several sources of systematic uncertainty are taken into account in the maximum-likelihood fit. For each source of uncertainty, the effects on the final distributions are considered correlated.

The assigned uncertainties in the integrated luminosity measurements for the data used in this analysis are 2.5, 2.3, and 2.5% for the 2016, 2017, and 2018 data samples [54, 55, 56], respectively. They are treated as uncorrelated across the three data sets.

The simulation of pileup events assumes a total inelastic pp cross section of 69.2 mb, with an associated uncertainty of 5% [57, 58], which has an impact on the expected signal and background yields of about 1%.

Discrepancies in the lepton and photon reconstruction and identification efficiencies between data and simulation are corrected by applying scale factors to all MC simulation samples. These scale factors are determined using $\cPZ\to\ell\ell$ events in the $\cPZ$ boson peak region that were recorded with unbiased triggers [48, 47]. The scale factors depend on the $\pt$ and $\eta$ of the lepton, and are within 2% of unity for both electrons and muons. The uncertainty in the determination of the trigger efficiency leads to an uncertainty smaller than 1% in the expected signal yield. The lepton momentum scale uncertainty is computed by varying the momenta of the leptons in simulation by their uncertainties, and repeating the analysis selection. The resulting yield uncertainties are $\approx$1% for both electrons and muons. The above procedure is applied also to determine the scale factors for photons, and the yield uncertainty for photon candidates is $\approx$1.5%. These uncertainties are treated as correlated across the three data sets.

The uncertainty in the calibration of the jet energy scale directly affects the acceptance of the jet multiplicity requirement and the $\ptmiss$ measurement. These effects are estimated by shifting the jet energy in the simulation up and down by one standard deviation. The uncertainty in the jet energy scale is 2–5%, depending on $\pt$ and $\eta$ [42], and the impact on the expected signal and background yields is about 3%.

In this analysis, \cPqb tagging is used to reject events with genuine $\cPqb$ quark jets in the final state, since signal events have no \cPqb quarks to first order in the decay channel of interest. The \cPqb tagging efficiency in the simulation is corrected using scale factors determined from data [45]. These values are estimated separately for correctly and incorrectly identified jets. Each set of values results in the \cPqb tagging efficiency of about 1–4%, and the impact on the expected signal and background yields is about 1%. The uncertainties in the jet energy scale and \cPqb tagging are treated as uncorrelated across the three data sets.

The theoretical uncertainties due to the choice of the QCD renormalization and factorization scales are estimated by varying these scales independently up and down by a factor of two [59, 60]. The variations of the PDF set and the strong coupling constant are used to estimate the corresponding uncertainties in the yields of the signal and background processes, following Refs. [33, 61]. The combined impact on the expected yields from the above sources is about 4%. The statistical uncertainty associated with the limited number of simulated events is also considered as part of the systematic uncertainty, leading to an impact on the expected yields of about 5%. These systematic uncertainties are much smaller than the statistical uncertainty because of the limited size of the data sample, and the effect of all systematic uncertainties reduces the sensitivity by less than 4%.

0.8 Results

The numbers of observed and expected events after applying the full selection requirements are shown in Table 1. The signal size is chosen for illustration purposes to be $0.1\sigma_{\cPZ\PH}$, to have a rounded number relatively close to the minimum where this analysis is expected to have sensitivity, and to avoid quoting large expected yields. The product of acceptance and selection efficiency increases at larger $m_{\PH}$ values because of the larger $\pt$ values for all objects in the events. The $\mT$ distributions for events with $\abs{\eta^{\gamma}}<1$ and $\abs{\eta^{\gamma}}>1$ after the event selection are shown in Fig. 3. Agreement between the data and the background-only prediction is observed.

By using the fit strategy described in Section 0.6, upper limits as a function of $m_{\PH}$ are derived for the product of $\sigma_{\cPZ\PH}$ and $\mathcal{B}(\PH\to\text{invisible}+\gamma)$. For $m_{\PH}=125\GeV$, this result can be interpreted as an upper limit on $\mathcal{B}(\PH\to\text{invisible}+\gamma)$ assuming the production rate for an SM Higgs boson [29]. The upper limits at 95% $\CL$ are calculated using a modified frequentist approach with the $\CLs$ criterion [62, 63] and asymptotic method for the test statistic [53, 64]. The observed (expected) 95% $\CL$ upper limit at $m_{\PH}=125\GeV$ on $\mathcal{B}(\PH\to\text{invisible}+\gamma)$ is 4.6 ($3.6^{+2.0}_{-1.2}$)%. The expected and observed cross section upper limits at 95% $\CL$ on the product of $\sigma_{\cPZ\PH}$ and $\mathcal{B}(\PH\to\text{invisible}+\gamma)$ as a function of $m_{\PH}$ are shown in Fig. 4. Exclusion limits at 95% $\CL$ on the product of $\sigma_{\cPZ\PH}$ and $\mathcal{B}(\PH\to\text{invisible}+\gamma)$ range from $\sim$40 to $\sim$4\unitfb as $m_{\PH}$ increases from 125 to 300\GeV. These limits also apply to other models where a scalar particle decays to a photon and light invisible particles.

0.9 Summary

A search is presented for a Higgs boson produced in association with a $\cPZ$ boson and decaying to an undetected particle together with an isolated photon. The analysis is based on a data set recorded by the CMS experiment in 2016–18 at a center-of-mass energy of $13\TeV$, corresponding to an integrated luminosity of $137\fbinv$. No significant excess of events above the expectation from standard model backgrounds is found. The results are used to place limits on the product of the cross section for associated $\cPZ\PH$ production and the branching fraction for such decays of the Higgs boson, in the context of a theoretical model where the undetected particle is a massless dark photon. The observed and expected upper limits at 95% confidence level at $m_{\PH}=125\GeV$ on $\mathcal{B}(\PH\to\text{invisible}+\gamma)$, assuming standard model $\cPZ\PH$ associated production, are 4.6 and 3.6%, respectively. Allowing for deviations from standard model $\cPZ\PH$ production, the product of $\sigma_{\cPZ\PH}$ and $\mathcal{B}(\PH\to\text{invisible}+\gamma)$ is excluded above $\sim$40 to $\sim$4\unitfb, for $m_{\PH}$ ranging from 125 to 300\GeV. These are the first limits on Higgs boson decays to final states that include an undetected massless dark photon.

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).

.10 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, 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, Q. Python, K. Skovpen, S. Tavernier, W. Van Doninck, P. Van Mulders \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, A. Popov, N. Postiau, E. Starling, L. Thomas, C. Vander Velde, P. Vanlaer, D. Vannerom \cmsinstskip**Ghent University, Ghent, Belgium

** T. Cornelis, D. Dobur, I. Khvastunov\cmsAuthorMark2, M. Niedziela, 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

** 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, 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

** G.M. Chen, H.S. Chen, M. Chen, C.H. Jiang, D. Leggat, H. Liao, Z. Liu, 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, Q. Wang \cmsinstskip**Tsinghua University, Beijing, China

** M. Ahmad, Z. Hu, Y. Wang \cmsinstskip**Zhejiang University - Department of Physics

** M. Xiao \cmsinstskip**Universidad de Los Andes, Bogota, Colombia

** C. Avila, A. Cabrera, 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

** Y. Assran\cmsAuthorMark11*,*\cmsAuthorMark12, S. Elgammal\cmsAuthorMark12 \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, M.S. Kim, 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\cmsAuthorMark13, M. Titov \cmsinstskip**Laboratoire Leprince-Ringuet, Ecole polytechnique, CNRS/IN2P3, Université Paris-Saclay, Palaiseau, France

** S. Ahuja, 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\cmsAuthorMark14, J. Andrea, D. Bloch, G. Bourgatte, J.-M. Brom, E.C. Chabert, C. Collard, E. Conte\cmsAuthorMark14, J.-C. Fontaine\cmsAuthorMark14, 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, A. Carle, 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, A. Lesauvage, M. Lethuillier, L. Mirabito, S. Perries, V. Sordini, L. Torterotot, G. Touquet, M. Vander Donckt, S. Viret \cmsinstskip**Georgian Technical University, Tbilisi, Georgia

** T. Toriashvili\cmsAuthorMark15 \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, J. Schulz, M. Teroerde, B. Wittmer \cmsinstskip**RWTH Aachen University, III. Physikalisches Institut A, Aachen, Germany

** A. Albert, M. Erdmann, B. 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, J. Roemer, A. Schmidt, S.C. Schuler, A. Sharma, S. Wiedenbeck, S. Zaleski \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, 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, 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. 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, 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, F. Feindt, 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, J. Multhaup, C.E.N. Niemeyer, A. Perieanu, A. Reimers, O. Rieger, C. Scharf, P. Schleper, S. Schumann, J. Schwandt, J. Sonneveld, H. Stadie, G. Steinbrück, F.M. Stober, 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, D. Müller, Th. Müller, M. Musich, A. Nürnberg, G. Quast, K. Rabbertz, M. Schröder, I. Shvetsov, H.J. Simonis, R. Ulrich, M. Wassmer, 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. Manousakis-katsikakis, A. Panagiotou, I. Papavergou, N. Saoulidou, A. Stakia, K. Theofilatos, K. Vellidis, E. Vourliotis \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, R. Chudasama, 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, 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. Dutta, S. Ghosh, M. Maity\cmsAuthorMark27, K. Mondal, S. Nandan, A. Purohit, P.K. Rout, 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

** 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, B. Kansal, 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, R. Alya**,b,\cmsAuthorMark29, C. Calabriaa**,b, A. Colaleoa, D. Creanzaa**,c, L. Cristellaa**,b, N. De Filippisa**,c, M. De Palmaa**,b, A. Di Florioa**,b, W. Elmetenaweea**,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, F.M. Simonea**,b, 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. Fontanesia**,b, P. Giacomellia, C. Grandia, L. Guiduccia**,b, F. Iemmia**,b, S. Lo Meoa**,\cmsAuthorMark30, 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,\cmsAuthorMark31, S. Costaa**,b, A. Di Mattiaa, R. Potenzaa**,b, A. Tricomia**,b,\cmsAuthorMark31, C. Tuve*a**,*b \cmsinstskip**INFN Sezione di Firenze a, Università di Firenze b, Firenze, Italy

** G. Barbaglia, A. Cassese, R. Ceccarelli, V. Ciullia**,b, C. Civininia, R. D’Alessandroa**,b, E. Focardia**,b, G. Latinoa**,b, P. Lenzia**,b, M. Meschinia, S. Paolettia, G. Sguazzonia, 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. Gennaia, A. Ghezzia**,b, P. Govonia**,b, L. Guzzia**,b, M. Malbertia, S. Malvezzia, D. Menascea, F. Montia**,b, L. Moronia, 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, D. Biselloa**,b, A. Bolettia**,b, A. Bragagnoloa**,b, R. Carlina**,b, P. Checchiaa, P. De Castro Manzanoa, T. Dorigoa, U. Dossellia, F. Gasparinia**,b, U. Gasparinia**,b, A. Gozzelinoa, S.Y. Hoha**,b, P. Lujana, M. Margonia**,b, A.T. Meneguzzoa**,b, J. Pazzinia**,b, M. Presillab, P. Ronchesea**,b, R. Rossina**,b, F. Simonettoa**,b, A. Tikoa, M. Tosi*a**,b, M. Zanettia**,b, P. Zottoa**,b, G. Zumerlea**,*b \cmsinstskip**INFN Sezione di Pavia a, Università di Pavia b, Pavia, Italy

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

** M. Biasinia**,b, G.M. Bileia, 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\cmsAuthorMark32, 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, 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, A. Bellora, 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, G. Ortonaa**,b, L. Pachera**,b, N. Pastronea, M. Pelliccionia, G.L. Pinna Angionia**,b, A. Romeroa**,b, M. Ruspaa**,c, 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, 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, J. Yoo \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.J 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\cmsAuthorMark33 \cmsinstskip**Vilnius University, Vilnius, Lithuania

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

** Z.A. Ibrahim, F. Mohamad Idris\cmsAuthorMark34, 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\cmsAuthorMark35, 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

** J. Mijuskovic, 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\cmsAuthorMark36, K. Doroba, A. Kalinowski, M. Konecki, J. Krolikowski, M. Misiura, M. Olszewski, 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, T. Niknejad, 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\cmsAuthorMark37*,*\cmsAuthorMark38, 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. Golovtcov, Y. Ivanov, V. Kim\cmsAuthorMark39, E. Kuznetsova\cmsAuthorMark40, 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\cmsAuthorMark41, 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\cmsAuthorMark42, M. Danilov\cmsAuthorMark42, S. Polikarpov\cmsAuthorMark42, 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\cmsAuthorMark43, L. Dudko, A. Ershov, A. Gribushin, V. Klyukhin, O. Kodolova, I. Lokhtin, S. Obraztsov, V. Savrin \cmsinstskip**Novosibirsk State University (NSU), Novosibirsk, Russia

** A. Barnyakov\cmsAuthorMark44, V. Blinov\cmsAuthorMark44, T. Dimova\cmsAuthorMark44, L. Kardapoltsev\cmsAuthorMark44, Y. Skovpen\cmsAuthorMark44 \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\cmsAuthorMark45, 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, R. Reyes-Almanza \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\cmsAuthorMark46, 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, P. Bortignon, 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, M. Deile, M. Dobson, M. Dünser, N. Dupont, A. Elliott-Peisert, N. Emriskova, F. Fallavollita\cmsAuthorMark47, D. Fasanella, S. Fiorendi, 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, N. Kratochwil, 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, J. Niedziela, 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. Rieger, M. Rovere, H. Sakulin, C. Schäfer, C. Schwick, M. Selvaggi, A. Sharma, P. Silva, W. Snoeys, P. Sphicas\cmsAuthorMark48, J. Steggemann, S. Summers, V.R. Tavolaro, D. Treille, A. Tsirou, G.P. Van Onsem, A. Vartak, M. Verzetti, W.D. Zeuner \cmsinstskip**Paul Scherrer Institut, Villigen, Switzerland

** L. Caminada\cmsAuthorMark49, 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.G. Ratti, 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\cmsAuthorMark50, 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, 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, A. Roy, 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 \cmsinstskip**Çukurova University, Physics Department, Science and Art Faculty, Adana, Turkey

** A. Bat, F. Boran, A. Celik\cmsAuthorMark51, S. Cerci\cmsAuthorMark52, S. Damarseckin\cmsAuthorMark53, Z.S. Demiroglu, F. Dolek, C. Dozen\cmsAuthorMark54, I. Dumanoglu, G. Gokbulut, EmineGurpinar Guler\cmsAuthorMark55, Y. Guler, I. Hos\cmsAuthorMark56, C. Isik, E.E. Kangal\cmsAuthorMark57, O. Kara, A. Kayis Topaksu, U. Kiminsu, G. Onengut, K. Ozdemir\cmsAuthorMark58, S. Ozturk\cmsAuthorMark59, A.E. Simsek, D. Sunar Cerci\cmsAuthorMark52, U.G. Tok, S. Turkcapar, I.S. Zorbakir, C. Zorbilmez \cmsinstskip**Middle East Technical University, Physics Department, Ankara, Turkey

** B. Isildak\cmsAuthorMark60, G. Karapinar\cmsAuthorMark61, M. Yalvac \cmsinstskip**Bogazici University, Istanbul, Turkey

** I.O. Atakisi, E. Gülmez, M. Kaya\cmsAuthorMark62, O. Kaya\cmsAuthorMark63, Ö. Özçelik, S. Tekten, E.A. Yetkin\cmsAuthorMark64 \cmsinstskip**Istanbul Technical University, Istanbul, Turkey

** A. Cakir, Y. Komurcu, S. Sen\cmsAuthorMark65 \cmsinstskip**Istanbul University, Istanbul, Turkey

** B. Kaynak, S. Ozkorucuklu \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

** E. Bhal, S. Bologna, J.J. Brooke, D. Burns\cmsAuthorMark66, 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, V.J. Smith, J. Taylor, A. Titterton \cmsinstskip**Rutherford Appleton Laboratory, Didcot, United Kingdom

** K.W. Bell, A. Belyaev\cmsAuthorMark67, 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\cmsAuthorMark68, 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\cmsAuthorMark69, V. Palladino, M. Pesaresi, D.M. Raymond, A. Richards, A. Rose, E. Scott, C. Seez, A. Shtipliyski, M. Stoye, T. Strebler, 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, B. Caraway, 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, A.M. Vargas Hernandez \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, Z. Demiragli, D. Gastler, C. Richardson, J. Rohlf, D. Sperka, I. Suarez, L. Sulak, D. Zou \cmsinstskip**Brown University, Providence, USA

** G. Benelli, B. Burkle, X. Coubez\cmsAuthorMark18, D. Cutts, Y.t. Duh, M. Hadley, U. Heintz, J.M. Hogan\cmsAuthorMark70, K.H.M. Kwok, E. Laird, G. Landsberg, K.T. Lau, J. Lee, Z. Mao, M. Narain, S. Sagir\cmsAuthorMark71, R. Syarif, E. Usai, D. Yu, W. Zhang \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. 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, Y. Chen, 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, S. Wimpenny, B.R. Yates, Y. Zhang \cmsinstskip**University of California, San Diego, La Jolla, USA

** J.G. Branson, P. Chang, S. Cittolin, S. Cooperstein, N. Deelen, 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 \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, 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, J.R. Patterson, D. Quach, A. Rinkevicius\cmsAuthorMark72, 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, D. Berry, 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, R. Vidal, M. Wang, H.A. Weber \cmsinstskip**University of Florida, Gainesville, USA

** D. Acosta, P. Avery, D. Bourilkov, A. Brinkerhoff, L. Cadamuro, A. Carnes, V. Cherepanov, 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, M. Hohlmann, D. Noonan, M. Rahmani, M. Saunders, F. Yumiceva \cmsinstskip**University of Illinois at Chicago (UIC), Chicago, USA

** M.R. Adams, L. Apanasevich, 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, J. Viinikainen, H. Wang, X. Wang, Z. Wu \cmsinstskip**The University of Iowa, Iowa City, USA

** M. Alhusseini, B. Bilki\cmsAuthorMark55, W. Clarida, K. Dilsiz\cmsAuthorMark73, S. Durgut, R.P. Gandrajula, M. Haytmyradov, V. Khristenko, O.K. Köseyan, J.-P. Merlo, A. Mestvirishvili\cmsAuthorMark74, A. Moeller, J. Nachtman, H. Ogul\cmsAuthorMark75, Y. Onel, F. Ozok\cmsAuthorMark76, A. Penzo, C. Snyder, E. Tiras, J. Wetzel \cmsinstskip**Johns Hopkins University, Baltimore, USA

** B. Blumenfeld, A. Cocoros, N. Eminizer, A.V. Gritsan, W.T. Hung, S. Kyriacou, P. Maksimovic, J. Roskes, M. Swartz \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

** R.M. Chatterjee, A. Evans, S. Guts, P. Hansen, J. Hiltbrand, 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. Kamalieddin, I. Kravchenko, J.E. Siado, G.R. Snow${}^{\textrm{\textdagger}}$, B. Stieger, W. Tabb \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, B. Marzocchi, 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\cmsAuthorMark37, 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

** 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

** U. Behrens, 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, O. Hindrichs, A. Khukhunaishvili, E. Ranken, 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, I. Laflotte, A. Lath, R. Montalvo, K. Nash, M. Osherson, H. Saka, S. Salur, S. Schnetzer, S. Somalwar, R. Stone, S. Thomas \cmsinstskip**University of Tennessee, Knoxville, USA

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

** O. Bouhali\cmsAuthorMark77, M. Dalchenko, M. De Mattia, A. Delgado, S. Dildick, R. Eusebi, J. Gilmore, T. Huang, T. Kamon\cmsAuthorMark78, S. Luo, S. Malhotra, 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, J. Hakala, 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 \cmsinstskip**University of Wisconsin - Madison, Madison, WI, USA

** T. Bose, J. Buchanan, C. Caillol, D. Carlsmith, S. Dasu, I. De Bruyn, L. Dodd, F. Fiori, C. Galloni, B. Gomber\cmsAuthorMark79, H. He, M. Herndon, A. Hervé, U. Hussain, P. Klabbers, A. Lanaro, A. Loeliger, K. Long, R. Loveless, J. Madhusudanan Sreekala, D. Pinna, 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 Suez University, Suez, Egypt

12: Now at British University in Egypt, Cairo, Egypt

13: Also at Purdue University, West Lafayette, USA

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

15: Also at Tbilisi State University, Tbilisi, Georgia

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: Now at INFN Sezione di Bari a, Università di Bari b, Politecnico di Bari c, Bari, Italy

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

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

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

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

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

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

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

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

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

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

40: Also at University of Florida, Gainesville, USA

41: Also at Imperial College, London, United Kingdom

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

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

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

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

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

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

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

49: Also at Universität Zürich, Zurich, Switzerland

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

51: Also at Burdur Mehmet Akif Ersoy University, BURDUR, Turkey

52: Also at Adiyaman University, Adiyaman, Turkey

53: Also at Şırnak University, Sirnak, Turkey

54: Also at Tsinghua University, Beijing, China

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

56: Also at Istanbul Aydin University, Istanbul, Turkey

57: Also at Mersin University, Mersin, Turkey

58: Also at Piri Reis University, Istanbul, Turkey

59: Also at Gaziosmanpasa University, Tokat, Turkey

60: Also at Ozyegin University, Istanbul, Turkey

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

62: Also at Marmara University, Istanbul, Turkey

63: Also at Kafkas University, Kars, Turkey

64: Also at Istanbul Bilgi University, Istanbul, Turkey

65: Also at Hacettepe University, Ankara, Turkey

66: Also at Vrije Universiteit Brussel, Brussel, Belgium

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

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

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

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

71: Also at Karamanoğlu Mehmetbey University, Karaman, Turkey

72: Also at Vilnius University, Vilnius, Lithuania

73: Also at Bingol University, Bingol, Turkey

74: Also at Georgian Technical University, Tbilisi, Georgia

75: Also at Sinop University, Sinop, Turkey

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

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

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

79: Also at University of Hyderabad, Hyderabad, India