A search for supersymmetry is presented based on events with large missing transverse energy, no isolated electron or muon, and at least three jets, with one or more identified as a bottomquark jet. A simultaneous examination is performed of the numbers of events in exclusive bins of the scalar sum of jet transverse momentum values, missing transverse energy, and bottomquark jet multiplicity. The sample, corresponding to an integrated luminosity of 19.4 , consists of protonproton collision data recorded at a centerofmass energy of 8 TeV with the CMS detector at the LHC in 2012. The observed numbers of events are found to be consistent with the standard model expectation, which is evaluated with control samples in data. The results are interpreted in the context of two simplified supersymmetric scenarios in which gluino pair production is followed by the decay of each gluino to an undetected lightest supersymmetric particle and either a bottom or top quarkantiquark pair, characteristic of gluino mediated bottom or topsquark production. Using the production cross section calculated to nexttoleadingorder plus nexttoleadinglogarithm accuracy, and in the limit of a massless lightest supersymmetric particle, we exclude gluinos with masses below 1170 GeV and 1020 GeV for the two scenarios, respectively.
Figure  Caption 

Figure 2. Schematic diagram illustrating the 176 mutually exclusive bins in the analysis. The MET and HT distributions are divided into four bins each; the table gives the bin definitions. The designations HT and MET () are used to label the individual HT and MET bins. The N_{bjet} distributions of the signal sample (ZL), topquark and W+jets control sample (SL), and QCD multijet control sample (LDP), contain three bins each, corresponding to exactly one, exactly two, and three or more identified b jets. 
Table 1. Observed numbers of events, SM background estimates from the fit, and SM expectations from Monte Carlo simulation, for the signal (ZL) regions with MET > 350 GeV and N_{bjet} = 2. The labels HT2, HT3, and HT4 refer to the bins of HT indicated in the first figure on this twiki, while HT24 is the sum over the three bins. The bottom row presents the SM background estimates from the sideband fit described in the text. The uncertainties listed for the fit results include the statistical and systematic components, while those shown for the simulation are statistical only. For the fits, the SUSY signal strength is fixed to zero.  
Table 2. Observed numbers of events, SM background estimates from the fit, and SM expectations from Monte Carlo simulation, for the signal (ZL) regions with MET >150 GeV and N_{bjet} >= 3. The labels HT1, HT2, MET2, etc., refer to the bins of HT and MET indicated in the first figure on this twiki, while HT14 (MET24) is the sum over the four HT (three MET) bins. The HT1MET4 bin is excluded from the analysis, as explained in the text. The bottom section presents the SM background estimates from the sideband fit described in the text. The uncertainties listed for the fit results include the statistical and systematic components, while those shown for the simulation are statistical only. For the fits, the SUSY signal strength is fixed to zero.  
Figure 6. Observed numbers of events (points with error bars) for the 14 bins with highest signal sensitivity in the analysis, in comparison with the standard model background predictions (with total uncertainties shown by the hatched bands) found in the fit with SUSY signal strength fixed to zero. The labels HT1, HT2, MET2, etc., refer to the bins of HT and MET indicated in the first figure on this twiki.  
Figure 7 (left). The 95 % CL upper limits on the T1bbbb newphysics scenario cross sections (pb) derived using the CL 

Figure 7 (right). The 95 % CL upper limits on the T1tttt newphysics scenario cross sections (pb) derived using the CL 
SM background estimates from the sideband fit for events with MET > 150 GeV and number of b jets ≥ 3. The labels HT1, HT2, MET2, etc., refer to the bins of HT and MET indicated in the schematic above (first figure on this twiki). HT14 (MET24) refers to the sum over the four HT (three MET) bins. The HT1MET4 bin is excluded from the analysis. Please see Section 5.6 of our PAS for more details 
T1bbbb selection efficiencies. In the root file efficiency_T1bbbb_multi.root we provide not only the histogram for the total 0lepton efficiency ("heff_tot"), but also the histograms of the efficiency in every 0lepton bin of the analysis ("heff_METx_HTy_nBz"  the boundaries of the (MET,HT,nB) bins are specified in the title of the root histogram). The plotted points reflect the density of the scan used to determine the efficiencies.  
T1tttt selection efficiencies. In the root file efficiency_T1tttt_multi.root we provide not only the histogram for the total 0lepton efficiency ("heff_tot"), but also the histograms of the efficiency in every 0lepton bin of the analysis ("heff_METx_HTy_nBz"  the boundaries of the (MET,HT,nB) bins are specified in the title of the root histogram). The plotted points reflect the density of the scan used to determine the efficiencies. 
Event 61509469, rhophi view, black background 
Event 61509469, rhophi view, black background, alternative color scheme 
Event 61509469, rhophi view, white background 
Event 61509469, 3D view, black background 
Event 61509469, 3D view, black background, alternative color scheme 
Event 61509469, 3D view, white background 
Event 94548608, rhophi view, black background 
Event 94548608, rhophi view, black background, alternative color scheme 
Event 94548608, rhophi view, white background 
Event 94548608, 3D view, black background 
Event 94548608, 3D view, black background, alternative color scheme 
Event 94548608, 3D view, white background 
The concept of "simplified models" is described here and here. The purpose is to link the LHC experiments and the theory communities interested in interpreting LHC data.
Figure  Caption 

Simplified model topology "T1bbbb".  
Simplified model topology "T1tttt".  
Simplified model topologies "T5tttt" and "T1t1t".  
Simplified model topology "T7btW". 
Figure  Caption 

Acceptance x selection efficiency (for the zerolepton sample) on the T7btw simplified model, with m(chi+) = 150 GeV, as a function of the mass of the gluino (x axis) and the mass of the sbottom (y axis). The root macro that can be used to reproduce this plot is T7btwmChi150_eff_RA2bXSEC.C.  
The 95 % CL upper limits on the T7btw simplified model (with m(chi+) = 150 GeV) cross sections (pb) derived using the CLs method. The solid (black) contours show the observed exclusions assuming the NLO+NLL cross sections, along with the +/ 1 standard deviation theory uncertainties. The dashed (red) contours present the corresponding expected results, along with the +/ 1 standard deviation experimental uncertainties. The root macro that can be used to reproduce this plot is T7btwmChi150RA2bXSEC.C. 
Figure  Caption 

Acceptance x selection efficiency (for the zerolepton sample) on the T7btw simplified model, with m(chi+) = 300 GeV, as a function of the mass of the gluino (x axis) and the mass of the sbottom (y axis). The root macro that can be used to reproduce this plot is T7btwmChi300_eff_RA2bXSEC.C.  
The 95 % CL upper limits on the T7btw simplified model (with m(chi+) = 300 GeV) cross sections (pb) derived using the CLs method. The solid (black) contours show the observed exclusions assuming the NLO+NLL cross sections, along with the +/ 1 standard deviation theory uncertainties. The dashed (red) contours present the corresponding expected results, along with the +/ 1 standard deviation experimental uncertainties. The root macro that can be used to reproduce this plot is T7btwmChi300RA2bXSEC.C. 
Figure  Caption 

Acceptance x selection efficiency (for the zerolepton sample) on the T5tttt simplified model as a function of the mass of the gluino (x axis) and the mass of the stop (y axis). The mass of the neutralino is fixed to 50 GeV. The root macro that can be used to reproduce this plot is T5tttt_eff_RA2bXSEC.C.  
The 95 % CL upper limits on the T5tttt simplified model cross sections (pb) derived using the CLs method. The solid (black) contours show the observed exclusions assuming the NLO+NLL cross sections, along with the +/ 1 standard deviation theory uncertainties. The dashed (red) contours present the corresponding expected results, along with the +/ 1 standard deviation experimental uncertainties. Cross section limits are presented for m(g ̃)  m(t ̃) > 200 GeV to ensure onshell top quarks in the final state. As the t ̃ mass decreases with fixed χ ̃^{0}_{1} mass, the χ ̃^{0}_{1} momentum in the t ̃ rest frame decreases. This results in less MET in the event, and thus less sensitivity in this search. The root macro that can be used to reproduce this plot is T5ttttRA2bXSEC.C. 
Figure  Caption 

Acceptance x selection efficiency (for the zerolepton sample) on the T1t1t simplified model as a function of the mass of the stop (x axis) and the mass of the neutralino (y axis). The mass of the gluino is fixed to 1000 GeV. The root macro that can be used to reproduce this plot is T1t1t_eff_RA2bXSEC.C.  
The 95 % CL upper limits on the T1t1t simplified model cross sections (pb) derived using the CLs method. The solid (black) contours show the observed exclusions assuming the NLO+NLL cross sections, along with the +/ 1 standard deviation theory uncertainties. The dashed (red) contours present the corresponding expected results, along with the +/ 1 standard deviation experimental uncertainties. Cross section limits are presented for m(t ̃)  m( χ ̃^{0}_{1}) > 100 GeV to ensure onshell W bosons from the top decay. As the stop mass decreases with fixed χ ̃^{0}_{1} mass, the χ ̃^{0}_{1} momentum in the t ̃ rest frame decreases. This results in less MET in the event, and thus less sensitivity in this search. The root macro that can be used to reproduce this plot is T1t1tRA2bXSEC.C. 
We show results of a phenomenological MSSM interpretation of the 8 TeV HT + MET + bjets analysis SUS12024.
We follow the approach of the phenomenological MSSM interpretation of 7 TeV CMS results, documented in the approved PAS SUS12030: About 7300 points in pMSSM parameter space are sampled from an evidencebased prior probability density, based on theoretical predictions and measurements of flavour observables, Higgs mass, top mass, bottom mass and anomalous magnetic moment of the muon. For each pMSSM point theta we calculate the likelihood L(SUS12024theta).
Results are presented as distributions of pMSSM parameters, masses and other observables, in two ways:
Figure  Caption 

Marginalized 1D probability distributions for ~g mass. The filled blue histogram shows the prior density. The line histograms show posterior densities after including the HT + MET + bjets analysis. The solid curve shows the posterior density obtained from likelihoods calculated using the central values of estimated signal counts s, whereas the dashed and dotted lines show the posterior densities obtained from likelihoods calculated using s0.5s and s+0.5s respectively.  
Marginalized 1D probability distributions for ~b_{1} mass. The filled blue histogram shows the prior density. The line histograms show posterior densities after including the HT + MET + bjets analysis. The solid curve shows the posterior density obtained from likelihoods calculated using the central values of estimated signal counts s, whereas the dashed and dotted lines show the posterior densities obtained from likelihoods calculated using s0.5s and s+0.5s respectively.  
Marginalized 1D probability distributions for the mass of the lightest colored sparticle. The filled blue histogram shows the prior density. The line histograms show posterior densities after including the HT + MET + bjets analysis. The solid curve shows the posterior density obtained from likelihoods calculated using the central values of estimated signal counts s, whereas the dashed and dotted lines show the posterior densities obtained from likelihoods calculated using s0.5s and s+0.5s respectively.  
Marginalized 1D probability distributions for sparticle production cross section. The filled blue histogram shows the prior density. The line histograms show posterior densities after including the HT + MET + bjets analysis. The solid curve shows the posterior density obtained from likelihoods calculated using the central values of estimated signal counts s, whereas the dashed and dotted lines show the posterior densities obtained from likelihoods calculated using s0.5s and s+0.5s respectively.  
Marginalized prior probability distribution for ~g mass versus ~χ_{1}^{0} mass. The grey and black contours enclose the 68% and 95% Bayesian credible regions respectively.  
Marginalized posterior probability distribution for ~g mass versus ~χ_{1}^{0} mass after including the HT + MET + bjets analysis. The grey and black contours enclose the 68% and 95% Bayesian credible regions respectively.  
Marginalized prior probability distribution for ~b_{1} mass versus ~χ_{1}^{0} mass. The grey and black contours enclose the 68% and 95% Bayesian credible regions respectively.  
Marginalized posterior probability distribution for ~b_{1} mass versus ~χ_{1}^{0} mass after including the HT + MET + bjets analysis. The grey and black contours enclose the 68% and 95% Bayesian credible regions respectively.  
Figure  Caption 

Distributions of ~g mass. The filled blue histogram shows the distribution of pMSSM points samped from the prior density. The red (black) line histograms shows the distribution of pMSSM points not excluded (excluded) by the HT + MET + bjets analysis. Solid curves show the posterior densities obtained from likelihoods calculated using the central values of estimated signal counts $s$, whereas the dashed and dotted lines show the posterior densities obtained from likelihoods calculated using s0.5s and s+0.5s respectively.  
Distributions of ~b_{1} mass. The filled blue histogram shows the distribution of pMSSM points samped from the prior density. The red (black) line histograms shows the distribution of pMSSM points not excluded (excluded) by the HT + MET + bjets analysis. Solid curves show the posterior densities obtained from likelihoods calculated using the central values of estimated signal counts $s$, whereas the dashed and dotted lines show the posterior densities obtained from likelihoods calculated using s0.5s and s+0.5s respectively.  
Distributions of the mass of the lightest colored sparticle. The filled blue histogram shows the distribution of pMSSM points samped from the prior density. The red (black) line histograms shows the distribution of pMSSM points not excluded (excluded) by the HT + MET + bjets analysis. Solid curves show the posterior densities obtained from likelihoods calculated using the central values of estimated signal counts $s$, whereas the dashed and dotted lines show the posterior densities obtained from likelihoods calculated using s0.5s and s+0.5s respectively.  
Distributions of the sparticle cross section. The filled blue histogram shows the posterior densities after preCMS measurements. The filled blue histogram shows the distribution of pMSSM points samped from the prior density. The red (black) line histograms shows the distribution of pMSSM points not excluded (excluded) by the HT + MET + bjets analysis. Solid curves show the posterior densities obtained from likelihoods calculated using the central values of estimated signal counts $s$, whereas the dashed and dotted lines show the posterior densities obtained from likelihoods calculated using s0.5s and s+0.5s respectively.  
Distribution of ~g mass versus ~χ_{1}^{0} mass for the sampled pMSSM points excluded by the HT + MET + bjets analysis. The grey and black contours enclose the 68% and 95% of the excluded points.  
Distribution of ~g mass versus ~χ_{1}^{0} mass for the sampled pMSSM points non excluded by the HT + MET + bjets analysis. The grey and black contours enclose 68% and 95% of the nonexcluded points.  
Distribution of ~b_{1} mass versus ~χ_{1}^{0} mass for the sampled pMSSM points excluded by the HT + MET + bjets analysis. The grey and black contours enclose the 68% and 95% of the excluded points.  
Distribution of ~b_{1} mass versus ~χ_{1}^{0} mass for the sampled pMSSM points not excluded by the HT + MET + bjets analysis. The grey and black contours enclose the 68% and 95% of the nonexcluded points.  
Figure  Formats  Caption 

pdf, png  Figure: Diagrams representing the T5Wh simplified model: Gluino pair production with , , and , .  
pdf, png  Figure: Diagrams representing the T5hh simplified model: Gluino pair production with , . 
Figure  Formats  Caption 

pdf, png  Signal efficiency for the T5Wh simplified model, as a function of the mass of the gluino (x axis) and the mass of the neutralino 1 (y axis).  
pdf, png  The 95 % CL upper limits on the T5Wh simplified model cross sections (pb) derived using the toy CLs method. The solid (black) contours show the observed exclusions, along with the +/ 1 standard deviation theory uncertainties. The dashed (red) contours present the corresponding expected results, along with the +/ 1 standard deviation experimental uncertainties. 
Figure  Formats  Caption 

pdf, png  Signal efficiency for the T5hh simplified model, as a function of the mass of the gluino (x axis) and the mass of the neutralino 1 (y axis).  
pdf, png  The 95 % CL upper limits on the T5Wh simplified model cross sections (pb) derived using the toy CLs method. The solid (black) contours show the observed exclusions, along with the +/ 1 standard deviation theory uncertainties. The dashed (red) contours present the corresponding expected results, along with the +/ 1 standard deviation experimental uncertainties. 
Figure  Formats  Caption 

pdf, png  Signal efficiency without the MET cut for the T5Wh simplified model, as a function of the mass of the gluino (x axis) and the mass of the neutralino 1 (y axis).  
pdf, png  Signal efficiency without the minDeltaPhiN cut for the T5Wh simplified model, as a function of the mass of the gluino (x axis) and the mass of the neutralino 1 (y axis).  
pdf, png  Signal efficiency without either the MET or the minDeltaPhiN cuts for the T5Wh simplified model, as a function of the mass of the gluino (x axis) and the mass of the neutralino 1 (y axis).  
pdf, png  Number of reconstructed jets of 50 GeV for the T5Wh signal with a gluino mass of 1 TeV and various LSP masses.  
pdf, png  MET distribution for the T5Wh signal with a gluino mass of 1 TeV and various LSP masses.  
pdf, png  minDeltaPhiN distribution for the T5Wh signal with a gluino mass of 1 TeV and various LSP masses.  
pdf, png  HT distribution for the T5hh signal with a gluino mass of 1 TeV and various LSP masses. 