CMS-PAS-SUS-15-005

CMS-PAS-SUS-15-005
Search for new physics in final states with jets and missing transverse momentum in $\sqrt{s} =$ 13 TeV pp collisions with the $\alpha_{\text{T}}$ variable
CMS Collaboration
December 2015

Abstract: An inclusive search for supersymmetric processes that produce final states with jets and missing transverse momentum is performed in pp collisions at a centre-of-mass energy of 13 TeV. A dimensionless kinematic variable, $\alpha_{\text{T}}$ , is used to discriminate between events with genuine and misreconstructed missing transverse momentum. A data sample corresponding to an integrated luminosity of 2.2 fb $^{-1}$ , recorded by the CMS experiment at the LHC, is analysed. The observed signal candidate event counts are found to be in agreement with the expected contributions from standard model processes and the result is interpreted in the mass parameter space of supersymmetric simplified models.
Links: CDS record (PDF) ; CADI line (restricted) ; These preliminary results are superseded in this paper, EPJC 77 (2017) 294. The superseded preliminary plots can be found here.

Figures
png ; pdf ;	Figure 1-a: Representations of simplified models comprising the pair production of gluinos and prompt three-body decays to $\mathrm{ q \bar{q} \tilde{ \chi } ^0 _1 }$ (a) and $\mathrm{ b \bar{b} \tilde{ \chi } ^0 _1 }$ (b) via an off-shell light-flavour or bottom squark, respectively.
png ; pdf ;	Figure 1-b: Representations of simplified models comprising the pair production of gluinos and prompt three-body decays to $\mathrm{ q \bar{q} \tilde{ \chi } ^0 _1 }$ (a) and $\mathrm{ b \bar{b} \tilde{ \chi } ^0 _1 }$ (b) via an off-shell light-flavour or bottom squark, respectively.
png ; pdf ;	Figure 2-a: (a) The ${\alpha _{\text {T}}}$ distribution observed in data for events that are recorded with unbiased trigger conditions and satisfy the baseline (full signal region) selection criteria for the region ${\alpha _{\text {T}}} <$ 0.55 ( ${\alpha _{\text {T}}} >$ 0.55). (b) The ${\Delta \phi ^{*}_{\rm min}}$ distribution observed in data for events that satisfy the full signal region selection criteria and ${H_{\mathrm {T}}} >$ 800 GeV. The distributions for the QCD multijet backgrounds are determined from simulation while all other SM backgrounds are estimated using a $\mu$ + jets data control sample.
png ; pdf ;	Figure 2-b: (a) The ${\alpha _{\text {T}}}$ distribution observed in data for events that are recorded with unbiased trigger conditions and satisfy the baseline (full signal region) selection criteria for the region ${\alpha _{\text {T}}} <$ 0.55 ( ${\alpha _{\text {T}}} >$ 0.55). (b) The ${\Delta \phi ^{*}_{\rm min}}$ distribution observed in data for events that satisfy the full signal region selection criteria and ${H_{\mathrm {T}}} >$ 800 GeV. The distributions for the QCD multijet backgrounds are determined from simulation while all other SM backgrounds are estimated using a $\mu$ + jets data control sample.
png ; pdf ;	Figure 3-a: The ${H_{\mathrm {T}}^{\text {miss}}}$ distribution observed in data and the expected distribution for the sum of all SM background processes in two representative event categories at high ${H_{\mathrm {T}}}$ . The expected distribution for an example benchmark model with a large (small) mass splitting between the gluino and LSP is also shown in the a (b) figure.
png ; pdf ;	Figure 3-b: The ${H_{\mathrm {T}}^{\text {miss}}}$ distribution observed in data and the expected distribution for the sum of all SM background processes in two representative event categories at high ${H_{\mathrm {T}}}$ . The expected distribution for an example benchmark model with a large (small) mass splitting between the gluino and LSP is also shown in the a (b) figure.
png ; pdf ;	Figure 4-a: Observed upper limit in cross section at 95% CL (indicated by the colour scale) for simplified models that assume the pair production of gluinos, as a function of the gluino and $\tilde{ \chi } ^0 _1$ masses for gluino three-body decays to $\mathrm{ b \bar{b} \tilde{ \chi } ^0 _1 }$ (a) and $\mathrm{ q \bar{q} \tilde{ \chi } ^0 _1 }$ (b). The black solid thick (thin) line indicates the observed mass exclusion region assuming the nominal ( ${\pm }1\sigma$ theory uncertainty) production cross section. The red dashed thick (thin) line indicates the median ( ${\pm }1 \sigma$ experimental uncertainty) expected exclusion.
png ; pdf ;	Figure 4-b: Observed upper limit in cross section at 95% CL (indicated by the colour scale) for simplified models that assume the pair production of gluinos, as a function of the gluino and $\tilde{ \chi } ^0 _1$ masses for gluino three-body decays to $\mathrm{ b \bar{b} \tilde{ \chi } ^0 _1 }$ (a) and $\mathrm{ q \bar{q} \tilde{ \chi } ^0 _1 }$ (b). The black solid thick (thin) line indicates the observed mass exclusion region assuming the nominal ( ${\pm }1\sigma$ theory uncertainty) production cross section. The red dashed thick (thin) line indicates the median ( ${\pm }1 \sigma$ experimental uncertainty) expected exclusion.

Compact Muon Solenoid
LHC, CERN