# Search for stealth supersymmetry in events with jets, either photons or leptons, and low missing momentum in pp collisions at 8 TeV (SUS-14-009)

## Abstract

The results of a search for new physics in final states with jets, either photons or leptons, and no requirement on missing transverse momentum are reported. The study is based on a sample of proton-proton collisions collected at center-of-mass energy TeV with the CMS detector in 2012. The integrated luminosity of the sample is 19.7 fb-1. Many models of new physics predict the production of events with jets, electroweak gauge bosons, and little or no missing transverse momentum. Examples include stealth models of supersymmetry (SUSY), which predict a hidden sector at the electroweak energy scale in which SUSY is approximately conserved. The data are used to search for stealth SUSY signatures in final states with either two photons or an oppositely charged electron and muon. No excess is observed with respect to the standard model expectation and the results are used to set limits on squark pair production in the stealth SUSY framework.

## Approved tables and plots

### Model description

Figure Caption
Figure 1: Decay of a squark to a quark and gaugino in stealth SUSY. Subsequent decay of the gaugino to a singlino produces a vector boson, and the singlino decay yields two gluons and a soft gravitino. The -S mass-splitting is taken to be 10 GeV, and we assume a mass of 100 GeV. In the analysis, a range of squark masses are considered from 300 to 1000 GeV, and the chargino is fixed to be half of the squark mass rounded up to the nearest 100 GeV. In the analysis, the squark mass ranges from 200 - 1400 GeV, and the neutralino mass varies from 150 to 1350 GeV with the requirement that the neutralino mass is always less than the squark mass.

### Photons

Figure Caption
Figure 2 (left): distributions in the analysis as a function of for simulated diphoton events passing selection A. The distributions are normalized to unit area. The lower plots show ratios with respect to the distribution.
Figure 2 (right): distributions in the analysis as a function of for data events passing selection B with one photon. The distributions are normalized to unit area. The lower plots show ratios with respect to the distribution.
Figure 4 (left): Measured distribution in comparison with the background prediction in the signal region of the analysis for . The systematic uncertainty of the background prediction and the expected distribution of signal events for GeV and either or 850 GeV are also shown.
Figure 4 (right): Measured distribution in comparison with the background prediction in the signal region of the analysis for . The systematic uncertainty of the background prediction and the expected distribution of signal events for GeV and either or 850 GeV are also shown.
Figure 6: Upper limits on squark and neutralino masses from the analysis. The -axis indicates the observed 95% CL upper limit on the signal model cross section. The solid lines represent the observed and median expected exclusion contours at a 95% CL with the corresponding band indicating the change in exclusion from variation of the theoretical and experimental uncertainties by one standard deviation.

### Leptons

Figure Caption
Figure 3: Distribution of for data and simulation in the analysis for the top-shape control region. The uncertainty on the MC event counts is determined by varying the renormalization/factorization scale by a factor of 2(1/2).
Figure 5: Measured distribution in comparison with the background prediction in the signal regions of the analysis. The lower plots show the ratio of the data to the background prediction, with the systematic uncertainty in the background prediction indicated.
Figure 7: Observed and median expected cross section upper limits as a function of squark mass from the analysis. The band about the expected limit indicates the one standard deviation experimental uncertainty. The NLO+NLL cross section with its one standard deviation uncertainty is also shown.

The production model for the signal is a simplified model of left handed ,, , squarks.

 Files Description root file containing TH2 of signal efficiency Stealth SUSY signal efficiency for diphoton selection, with > 1200 GeV, as a function of squark mass and neutralino mass. The signal efficiency is given separately for 4 and 5 jets. result_2Photons_4Jets ROOT file containing data, signal MC, expected background, and background estimation uncertainties corresponding to Figure 4 (left). The histogram h_data represents the number of observed events in bins of 100 GeV, h_mc is the expected signal MC for a squark/neutralino mass of 900/450 GeV, and h_mc2 is the expected signal MC for a squark/neutralino mass of 900/850 GeV. The histograms bkg, bkg_bkgTotUp, and bkg_bkgTotDown contain the expected background contribution in 10 GeV bins, with the total up/down uncertainty from all sources. result_2Photons_5Jets ROOT file containing data, signal MC, expected background, and background estimation uncertainties corresponding to Figure 4 (right). The histogram h_data represents the number of observed events in bins of 100 GeV,h_mc is the expected signal MC for a squark/neutralino mass of 900/450 GeV, and h_mc2 is the expected signal MC for a squark/neutralino mass of 900/850 GeV. The histograms bkg, bkg_bkgTotUp, and bkg_bkgTotDown contain the expected background contribution in 10 GeV bins, with the total up/down uncertainty from all sources. photonLimits ROOT file containing the observed and expected cross section limits corresponding to Figure 6. The histogram obsXSecLimit gives the observed cross section limit for the photon analysis as a function of squark and neutralino masses. The histogram expXSecLimit gives the corresponding expected cross section limit, and the histograms expXSecLimitUp and expXSecLimitDown give the expected limits when the experimental uncertainty is varied up and down by 1 sigma. pdf Table 1: Event counts for lepton analysis with 0 b-tags, binnded exclusive bins of jet multiplicity, and three inclusive bins. We apply thresholds of = 300 GeV for = 300 GeV, = 700 GeV for values of 400 and 500 GeV, and =1200 GeV for 600 GeV. Table 2: Event counts for lepton analysis in 2 b-tag control sample, binned in exclusive jet multiplicity, and three inclusive bins. The uncertainty on the MC event counts is determined by varying the renormalization/factorization scale by a factor of 2(1/2). cutFlowTables Cut flows for the photon (Table 1) and lepton (Table 2) analyses with efficiencies for benchmark signal points. The full selection efficiencies for the signal points in the search region are also shown for the photon (bottom of Table 1) and lepton (Table 3) analyses.

Topic attachments
I Attachment History Action Size Date Who Comment
root stealth_susy_signal_efficiency_diphoton.root r1 manage 6.8 K 2014-08-29 - 20:32 AlexeyFerapontov
root result_2Photons_4Jets.root r4 r3 r2 r1 manage 7.5 K 2014-09-02 - 22:23 MarcWeinberg
root result_2Photons_5Jets.root r4 r3 r2 r1 manage 7.5 K 2014-09-02 - 22:23 MarcWeinberg
jpg feynmanSquarkDecay.jpg r1 manage 7.8 K 2014-11-07 - 20:37 MarcWeinberg
pdf feynmanSquarkDecay.pdf r2 r1 manage 10.2 K 2014-11-07 - 20:37 MarcWeinberg
pdf SignalCutFlowTable.pdf r1 manage 11.7 K 2014-09-02 - 23:18 BenCarlson
root allLimitHists.root r2 r1 manage 13.1 K 2014-09-02 - 05:45 MarcWeinberg
pdf Limit_Plot.pdf r8 r7 r6 r5 r4 manage 13.6 K 2014-11-14 - 10:08 MarcWeinberg
pdf st_gg4J_doublePhoton_2Photon.pdf r8 r7 r6 r5 r4 manage 16.6 K 2014-11-13 - 07:04 MarcWeinberg
pdf st_jetHt_1Photon.pdf r6 r5 r4 r3 r2 manage 16.9 K 2014-11-13 - 07:02 MarcWeinberg
pdf result_doublePhoton_2Photon_4Jet.pdf r7 r6 r5 r4 r3 manage 17.9 K 2014-11-19 - 05:16 MarcWeinberg
pdf result_doublePhoton_2Photon_5Jet.pdf r7 r6 r5 r4 r3 manage 18.4 K 2014-11-19 - 05:19 MarcWeinberg
pdf totalLimit.pdf r7 r6 r5 r4 r3 manage 21.1 K 2014-11-18 - 16:51 MarcWeinberg
pdf EventCategories_1Mu_1El_0btag_SF_expectedbkg_stack_canvas.pdf r6 r5 r4 r3 r2 manage 24.8 K 2014-11-13 - 17:32 BenCarlson
pdf cutFlowTables.pdf r3 r2 r1 manage 32.1 K 2014-09-08 - 23:48 MarcWeinberg
pdf EventCategories_1Mu_1El_2btag_SF_stack_canvas.pdf r6 r5 r4 r3 r2 manage 32.8 K 2014-11-13 - 17:32 BenCarlson
png feynmanSquarkDecay.png r4 r3 r2 r1 manage 39.8 K 2014-11-10 - 15:02 MarcWeinberg
pdf SummaryEventCounts_.pdf r3 r2 r1 manage 50.5 K 2014-09-08 - 20:01 BenCarlson
pdf SummaryEventCounts.pdf r2 r1 manage 50.9 K 2014-12-02 - 18:29 BenCarlson
jpg st_gg4J_doublePhoton_2Photon.jpg r8 r7 r6 r5 r4 manage 54.1 K 2014-11-13 - 07:05 MarcWeinberg
jpg st_jetHt_1Photon.jpg r6 r5 r4 r3 r2 manage 54.4 K 2014-11-13 - 07:03 MarcWeinberg
pdf stealth_susy_signal_efficiency_diphoton.pdf r1 manage 57.5 K 2014-08-29 - 20:32 AlexeyFerapontov
jpg Limit_Plot.jpg r8 r7 r6 r5 r4 manage 60.9 K 2014-11-14 - 10:06 MarcWeinberg
jpg result_doublePhoton_2Photon_4Jet.jpg r7 r6 r5 r4 r3 manage 61.3 K 2014-11-19 - 05:12 MarcWeinberg
jpg result_doublePhoton_2Photon_5Jet.jpg r7 r6 r5 r4 r3 manage 61.8 K 2014-11-19 - 05:17 MarcWeinberg
jpg totalLimit.jpg r7 r6 r5 r4 r3 manage 75.7 K 2014-11-18 - 16:49 MarcWeinberg
jpg EventCategories_1Mu_1El_2btag_SF_stack_canvas.jpg r8 r7 r6 r5 r4 manage 75.8 K 2014-11-13 - 18:40 MarcWeinberg
jpg EventCategories_1Mu_1El_0btag_SF_expectedbkg_stack_canvas.jpg r8 r7 r6 r5 r4 manage 83.8 K 2014-11-13 - 18:39 MarcWeinberg

This topic: CMSPublic > SUS14009 > PhysicsResultsSUS14009
Topic revision: r43 - 2014-12-02 - BenCarlson

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