Search for supersymmetry in hadronic final states with missing transverse energy using the variables AlphaT and b-quark multiplicity in pp collisions at 8 TeV

TL;DR

This paper reports a search for supersymmetry in proton-proton collisions at 8 TeV using the AlphaT variable and b-quark multiplicity, setting exclusion limits on gluino and squark masses with no significant excess found.

Contribution

It introduces a novel analysis method combining AlphaT and b-quark multiplicity to improve supersymmetry searches at the LHC.

Findings

Excluded gluino masses up to 1125 GeV

Excluded squark masses up to 600 GeV

No significant excess over the standard model

Abstract

An inclusive search for supersymmetric processes that produce final states with jets and missing transverse energy is performed in pp collisions at a centre-of-mass energy of 8 TeV. The data sample corresponds to an integrated luminosity of 11.7 inverse femtobarns collected by the CMS experiment at the LHC. In this search, a dimensionless kinematic variable, AlphaT, is used to discriminate between events with genuine and misreconstructed missing transverse energy. The search is based on an examination of the number of reconstructed jets per event, the scalar sum of transverse energies of these jets, and the number of these jets identified as originating from bottom quarks. No significant excess of events over the standard model expectation is found. Exclusion limits are set in the parameter space of simplified models, with a special emphasis on both compressed-spectrum scenarios and direct or gluino-induced production of third-generation squarks. For the case of gluino-mediated squark production, gluino masses up to 950-1125 GeV are excluded depending on the assumed model. For the direct pair-production of squarks, masses up to 450 GeV are excluded for a single light first- or second-generation squark, increasing to 600\GeV for bottom squarks.