Search for supersymmetry using hadronic top quark tagging in 13 TeV pp collisions (SUS-16-050)

Further information

Replace with arxive link when avaliable This analysis is documented in CMS-PAS-SUS-16-050.

Replace with public webpage link when avaliable The public webpage for this analysis is http://cms-results.web.cern.ch/cms-results/public-results/preliminary-results/SUS-16-050/index.html

Technical plots for CMS speakers

Top Tagger

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Figure	Caption
	The discriminant distribution for the MVA trained for the triple-jet category top tagger in semileptonic ttbar MC after the following requirements: pTmiss > 250 GeV, no electron or muon with pT > 10 GeV, at least 4 jets with pT > 30 GeV, the Δφ between the three leading pT jets and the pTmiss must be greater than 0.3, and at least one b-tagged jet. The results are shown separately for top candidates matched to generator level top quarks and unmatched candidates.
	The misidentification rate of the top tagger used in SUS-16-050 in comparison with the previous cut-base version of the top tagger used in SUS-16-009. The misidentification rate is calculated on an event-wise basis using Z->nunu MC as the ratio of events with at least one reconstructed top quark to the total number of events as a function of pTmiss. The results are produced from a ttbar MC sample generated with one leptonic and one hadronicaly decaying top with the following requirements: pTmiss > 250 GeV, no electron or muon with pT > 10 GeV, at least 4 jets with pT > 30 GeV, the Δφ between the three leading pT jets and the pTmiss must be greater than 0.3, and at least one b-tagged jet.
	The trijet candidate mass variable which is input to the top tagger. The distribution is shown for 4 different categories: the candidates passing/failing the MVA random forest discriminator are show in red/blue respectively while those matched to a generator level top quark vs unmatched ane shown in dotted green/black respectively. The results are produced from a ttbar MC sample generated with one leptonic and one hadronicaly decaying top with the following requirements: pTmiss > 250 GeV, no electron or muon with pT > 10 GeV, at least 4 jets with pT > 30 GeV, the Δφ between the three leading pT jets and the pTmiss must be greater than 0.3, and at least one b-tagged jet.
	The invariant mass of the second and third highest momentum jets in the trijet rest frame which is input to the top tagger. The second and third highest momentum jets sorted in the rest frame should form the W candidate. The distribution is shown for 4 different categories: the candidates passing/failing the MVA random forest discriminator are show in red/blue respectively while those matched to a generator level top quark vs unmatched ane shown in dotted green/black respectively. The results are produced from a ttbar MC sample generated with one leptonic and one hadronicaly decaying top with the following requirements: pTmiss > 250 GeV, no electron or muon with pT > 10 GeV, at least 4 jets with pT > 30 GeV, the Δφ between the three leading pT jets and the pTmiss must be greater than 0.3, and at least one b-tagged jet.
	The angular separation in the trijet restframe between the second and third highest momentum jets in the trijet rest frame which is input to the top tagger. The distribution is shown for 4 different categories: the candidates passing/failing the MVA random forest discriminator are show in red/blue respectively while those matched to a generator level top quark vs unmatched ane shown in dotted green/black respectively. The results are produced from a ttbar MC sample generated with one leptonic and one hadronicaly decaying top with the following requirements: pTmiss > 250 GeV, no electron or muon with pT > 10 GeV, at least 4 jets with pT > 30 GeV, the Δφ between the three leading pT jets and the MET must be greater than 0.3, and at least one b-tagged jet.
	The momentum of the highest momentum jet in the trijet rest frame which is input to the top tagger. The distribution is shown for 4 different categories: the candidates passing/failing the MVA random forest discriminator are show in red/blue respectively while those matched to a generator level top quark vs unmatched are shown in dotted green/black respectively. The results are produced from a ttbar MC sample generated with one leptonic and one hadronicaly decaying top with the following requirements: pTmiss > 250 GeV, no electron or muon with pT > 10 GeV, at least 4 jets with pT > 30 GeV, the Δφ between the three leading pT jets and the pTmiss must be greater than 0.3, and at least one b-tagged jet.
	The combined secondary vertex (CSV) b-tagging discriminator of the highest momentum jet in the trijet rest frame which is input to the top tagger. The discontinuity around 0.84 is due to the requirement that no top can have more than one b-tagged jet. The distribution is shown for 4 different categories: the candidates passing/failing the MVA random forest discriminator are show in red/blue respectively while those matched to a generator level top quark vs unmatched are shown in dotted green/black respectively. The results are produced from a ttbar MC sample generated with one leptonic and one hadronicaly decaying top with the following requirements: pTmiss > 250 GeV, no electron or muon with pT > 10 GeV, at least 4 jets with pT > 30 GeV, the Δφ between the three leading pT jets and the pTmiss must be greater than 0.3, and at least one b-tagged jet.

Background prediction from Monte Carlo

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Figure	Caption
	Background composition in 0-lepton search region in bins of the number of b-tagged jets and the number of top-tagged candidates from the simulated events.

Background prediction from analysis

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Figure	Caption
	The distribution of HT is shown for data and the final pre-fit background prediction in the signal region. The selection is described in section 8 of the paper. Four example signal points, normalized to their expected cross sections) are also shown for comparison. The choice of binning is chosen to approximately match the binning used in the primary search bins of the analysis.
	The distribution of pTmiss is shown for data and the final pre-fit background prediction in the signal region. The selection is described in section 8 of the paper. Four example signal points, normalized to their expected cross sections) are also shown for comparison. The choice of binning is chosen to approximately match the binning used in the primary search bins of the analysis.
	The distribution of MT2 is shown for data and the final pre-fit background prediction in the signal region. The selection is described in section 8 of the paper. Four example signal points, normalized to their expected cross sections) are also shown for comparison. The choice of binning is chosen to approximately match the binning used in the primary search bins of the analysis.
	The distribution of Nb is shown for data and the final pre-fit background prediction in the signal region. The selection is described in section 8 of the paper. Four example signal points, normalized to their expected cross sections) are also shown for comparison. The choice of binning is chosen to approximately match the binning used in the primary search bins of the analysis.
	The distribution of Nt is shown for data and the final pre-fit background prediction in the signal region. The selection is described in section 8 of the paper. Four example signal points, normalized to their expected cross sections) are also shown for comparison. The choice of binning is chosen to approximately match the binning used in the primary search bins of the analysis.

Event Display

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Figure	Caption
	Event displays for a SUSY candidate event with two reconstructed top-jets (one is in di-jet case, the other is in tri-jet case) in the search region, 274250:425322875:212 in view with a white background. The momenta of the AK4 jets that tagged as b-jet in tri-jet case are marked in green, other AK4 jets are marked in blue, the momentum of the AK8 jets are marked in yellow and missing transverse momentum is marked in purple.
	Event displays for a SUSY candidate event with two reconstructed top-jets (one is in mono-jet case, the other is in tri-jet case) in the search region, 274969:766814305:417 in view with a white background. The momenta of the AK4 jets that tagged as b-jet in tri-jet case are marked in green, other AK4 jets are marked in blue, the momentum of the AK8 jets are marked in yellow and missing transverse momentum is marked in purple.