PhysicsResultsSUS14009 < CMSPublic

CMSPublic Web>SUS14009>PhysicsResultsSUS14009 (2014-12-03, KeithUlmer) (raw view)

---+ Search for stealth supersymmetry in events with jets, either photons or leptons, and low missing momentum in pp collisions at 8 !CMS.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 %$\sqrt{s} = 8$% !CMS.TeV with the CMS
  detector in 2012. The integrated luminosity of the sample is 19.7 fb<sup>-1</sup>. 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* |||
| [[%ATTACHURL%/feynmanSquarkDecay.pdf][<img alt="feynmanSquarkDecay.png" height="125" src="%ATTACHURL%/feynmanSquarkDecay.png" title="feynmanSquarkDecay.png" width="400" />]] | *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 %$\tilde{S}$%-S mass-splitting is taken to be 10 !CMS.GeV, and we assume a %$\tilde{S}$% mass of 100 !CMS.GeV. In the %$\ell^\pm$% analysis, a range of squark masses are considered from 300 to 1000 !CMS.GeV, and the chargino is fixed to be half of the squark mass rounded up to the nearest 100 !CMS.GeV. In the %$\gamma$% analysis, the squark mass ranges from 200 - 1400 !CMS.GeV, and the neutralino mass varies from 150 to 1350 !CMS.GeV with the requirement that the neutralino mass is always less than the squark mass. |||
---+++ Photons
| *Figure* | *Caption* |||
| [[%ATTACHURL%/st_gg4J_doublePhoton_2Photon.pdf][<img alt="st_gg4J_doublePhoton_2Photon.jpg" height="426" src="%ATTACHURL%/st_gg4J_doublePhoton_2Photon.jpg" title="st_gg4J_doublePhoton_2Photon.jpg" width="400" />]] | *Figure 2 (left)*: %$S_{T}$% distributions in the %$\gamma$% analysis as a function of %$N_{\mathrm{jets}}$% for simulated diphoton events passing selection A. The distributions are normalized to unit area. The lower plots show ratios with respect to the %$N_{\mathrm{jets}} = 3$% distribution. |||
| [[%ATTACHURL%/st_jetHt_1Photon.pdf][<img alt="st_jetHt_1Photon.jpg" height="426" src="%ATTACHURL%/st_jetHt_1Photon.jpg" title="st_jetHt_1Photon.jpg" width="400" />]] | *Figure 2 (right)*: %$S_{T}$% distributions in the %$\gamma$% analysis as a function of %$N_{\mathrm{jets}}$% 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 %$N_{\mathrm{jets}} = 3$% distribution. |||
| [[%ATTACHURL%/result_doublePhoton_2Photon_4Jet.pdf][<img alt="result_doublePhoton_2Photon_4Jet.jpg" height="432" src="%ATTACHURL%/result_doublePhoton_2Photon_4Jet.jpg" title="result_doublePhoton_2Photon_4Jet.jpg" width="400" />]] | *Figure 4 (left)*: Measured %$S_{T}$% distribution in comparison with the background prediction in the signal region of the %$\gamma$% analysis for %$N_{\mathrm{jets}} = 4$%. The systematic uncertainty of the background prediction and the expected distribution of signal events for %$M_{\tilde{q}} = 900$% !CMS.GeV and either %$M_{\tilde{\chi}_{1}^{0}} = 450$% or 850 !CMS.GeV are also shown. |||
| [[%ATTACHURL%/result_doublePhoton_2Photon_5Jet.pdf][<img alt="result_doublePhoton_2Photon_5Jet.jpg" height="432" src="%ATTACHURL%/result_doublePhoton_2Photon_5Jet.jpg" title="result_doublePhoton_2Photon_5Jet.jpg" width="400" />]] | *Figure 4 (right)*: Measured %$S_{T}$% distribution in comparison with the background prediction in the signal region of the %$\gamma$% analysis for %$N_{\mathrm{jets}} \geq 5$%. The systematic uncertainty of the background prediction and the expected distribution of signal events for %$M_{\tilde{q}} = 900$% !CMS.GeV and either %$M_{\tilde{\chi}_{1}^{0}} = 450$% or 850 !CMS.GeV are also shown. |||
| [[%ATTACHURL%/totalLimit.pdf][<img alt="totalLimit.jpg" height="409" src="%ATTACHURL%/totalLimit.jpg" title="totalLimit.jpg" width="400" />]] | *Figure 6*: Upper limits on squark and neutralino masses from the %$\gamma$% analysis. The %$z$%-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* |||
| [[%ATTACHURL%/EventCategories_1Mu_1El_2btag_SF_stack_canvas.pdf][<img alt="EventCategories_1Mu_1El_2btag_SF_stack_canvas.jpg" height="388" src="%ATTACHURL%/EventCategories_1Mu_1El_2btag_SF_stack_canvas.jpg" title="EventCategories_1Mu_1El_2btag_SF_stack_canvas.jpg" width="400" />]] | *Figure 3*: Distribution of %$N_{\mathrm{jets}}$% for data and simulation in the %$\ell^\pm$% 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). |||
| [[%ATTACHURL%/EventCategories_1Mu_1El_0btag_SF_expectedbkg_stack_canvas.pdf][<img alt="EventCategories_1Mu_1El_0btag_SF_expectedbkg_stack_canvas.jpg" height="388" src="%ATTACHURL%/EventCategories_1Mu_1El_0btag_SF_expectedbkg_stack_canvas.jpg" title="EventCategories_1Mu_1El_0btag_SF_expectedbkg_stack_canvas.jpg" width="400" />]] | *Figure 5*: Measured %$N_{\mathrm{jets}}$% distribution in comparison with the background prediction in the signal regions of the %$\ell^{\pm}$% analysis. The lower plots show the ratio of the data to the background prediction, with the systematic uncertainty in the background prediction indicated. |||
| [[%ATTACHURL%/Limit_Plot.pdf][<img alt="Limit_Plot.jpg" height="404" src="%ATTACHURL%/Limit_Plot.jpg" title="Limit_Plot.jpg" width="400" />]] | *Figure 7*: Observed and median expected cross section upper limits as a function of squark mass from the %$\ell^\pm$% 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. |||
---+++ Additional information

The production model for the signal is a simplified model of left handed %$\tilde{u}$%,%$\tilde{d}$%, %$\tilde{s}$%, %$\tilde{c}$% squarks.

| Files | Description |
| <p> [[%ATTACHURL%/stealth_susy_signal_efficiency_diphoton.root][root]] file containing TH2 of signal efficiency</p> <p> [[%ATTACHURL%/stealth_susy_signal_efficiency_diphoton.pdf][pdf]]</p> | Stealth !SUSY *signal efficiency* for diphoton selection, with %$S_{T}$% &gt; 1200 !CMS.GeV, as a function of squark mass and neutralino mass. The signal efficiency is given separately for 4 and %$\geq$% 5 jets. |
| [[%ATTACHURL%/result_2Photons_4Jets.root][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 !CMS.GeV, h_mc is the expected signal MC for a squark/neutralino mass of 900/450 !CMS.GeV, and h_mc2 is the expected signal MC for a squark/neutralino mass of 900/850 !CMS.GeV. The histograms bkg, bkg_bkgTotUp, and bkg_bkgTotDown contain the expected background contribution in 10 !CMS.GeV bins, with the total up/down uncertainty from all sources. |
| [[%ATTACHURL%/result_2Photons_5Jets.root][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 !CMS.GeV,h_mc is the expected signal MC for a squark/neutralino mass of 900/450 !CMS.GeV, and h_mc2 is the expected signal MC for a squark/neutralino mass of 900/850 !CMS.GeV. The histograms bkg, bkg_bkgTotUp, and bkg_bkgTotDown contain the expected background contribution in 10 !CMS.GeV bins, with the total up/down uncertainty from all sources. |
| [[%ATTACHURL%/allLimitHists.root][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. |
| [[%ATTACHURL%/SummaryEventCounts.pdf][pdf]] | <p>Table 1: *Event counts* for lepton analysis with 0 b-tags, binnded exclusive bins of jet multiplicity, and three inclusive %$S_{T}$% bins. We apply thresholds of %$S_{T}$% = 300 !CMS.GeV for %$M_{\tilde{q}}$% = 300 !CMS.GeV, %$S_{T}$% = 700 !CMS.GeV for %$M_{\tilde{q}}$% values of 400 and 500 !CMS.GeV, and %$S_{T}$% =1200 !CMS.GeV for %$M_{\tilde{q}}$% %$\geq$% 600 !CMS.GeV.</p> <p>Table 2: *Event counts* for lepton analysis in %$\geq$% 2 b-tag control sample, binned in exclusive jet multiplicity, and three inclusive %$S_{T}$% bins. The uncertainty on the MC event counts is determined by varying the renormalization/factorization scale by a factor of 2(1/2).</p> <p> </p> |
| [[%ATTACHURL%/cutFlowTables.pdf][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. |

Attachments

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

Topic revision: r44 - 2014-12-03 - KeithUlmer

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