RPV Stop Search

Abstract

We present a search for anomalous production of events with three or more isolated leptons and at least one bottom-quark jet produced in pp collisions at √s = 8 TeV. We analyze 19.5 fb^-1 of data collected by the CMS experiment during the 2012 LHC run. No excesses above the standard model expectations are observed. We interpret the search results in the context of supersymmetric models with diminished missing transverse energy signatures arising from light stop pair production with R-parity- violating decays of the lightest supersymmetric particle.

Link to Paper

arXiv:1306.6643

Approved Plots from SUS-13-003

Plots from Paper

Figure	Abbreviated Caption
	Figure 1: Background breakdown vs ST for 3-leptons + OSSF1 off-Z + Tau0 + at least 1 b-jet
	Figure 2 (a): Exclusion plot for Stop-RPV with LLE122 coupling non-zero. The region to the left of the curve is excluded.
	Figure 2 (b): Exclusion plot for Stop-RPV with LLE233 coupling non-zero. The region to the left of the curve is excluded.
	Figure 2(c) Exclusion plot for Stop-RPV with LQD233 coupling non-zero. The region inside the curve is excluded. The different regions, A, B, C, D, and E, for the LQD233 exclusion result from different stop decay products as explained in Table 2
	Table 1: Observed yields for three- and four- lepton events from 19.5 fb^-1 recorded in 2012. The channels are split by the total number of leptons (N_L), the number of tau candidates (N_tau), and the ST. Expected yields are the sum of simulation and estimates of backgrounds from data in each channel. SR1--SR4 require a b-tagged jet and veto events containing Z bosons. SR5--SR8 contain events that either contain a Z boson or have no b-tagged jet. The channels are mutually exclusive. The uncertainties include statistical and systematic uncertainties. The ST values are given in GeV
	Table 2: Kinematically allowed stop decay modes with RPV coupling LQD233. The allowed neutralino decay modes for m_t < m_chi10 < m_stop are chi10 to mu t bbar and nu b bbar.

Additional Plots

	Background breakdown vs ST for 3-leptons + OSSF1 off-Z + Tau1 + at least 1 b-jet
	Background breakdown vs ST for 4-leptons + OSSF1/2 + off-Z + Tau0 + at least 1 b-jet
	Background breakdown vs ST for 4-leptons + OSSF1/2 + off-Z + Tau1 + at least 1 b-jet
	Feynman Diagram for Stop-RPV with LLE122 coupling non-zero
	Feynman Diagram for Stop-RPV with LLE233 coupling non-zero
	Feynman Diagram for Stop-RPV with LQD233 coupling non-zero

	Exclusion plot for Stop-RPV with LLE122 coupling non-zero, with observed Cross-section upper-limits overlaid. The curve is almost vertical due to decoupling of the bino. The values can be found in Limit_LLE122.root.
	Exclusion plot for Stop-RPV with LLE233 coupling non-zero, with observed Cross-section upper-limits overlaid. The curve is almost vertical due to decopuling of the bino. The feature around (800 GeV, 800 GeV) is due to a sensitivity loss in the region where the top is off-shell. The values can be found in Limit_LLE233.root.
	Exclusion plot for Stop-RPV with LQD233 coupling non-zero, with observed Cross-section upper-limits overlaid. The values can be found in Limit_LQD233.root.
	Efficiency plot for Stop-RPV with LLE122 coupling non-zero. The values can be found in EffAcc_LLE122.root (summed up) and in EffAcc_LLE122_perChannel.root (channel breakdown).
	Efficiency plot for Stop-RPV with LLE233 coupling non-zero. The values can be found in EffAcc_LLE233.root (summed up) and in EffAcc_LLE233_perChannel.root (channel breakdown).
	Efficiency plot for Stop-RPV with LQD233 coupling non-zero. The values can be found in EffAcc_LQD233.root (summed up) and in EffAcc_LQD233_perChannel.root (channel breakdown).
	S_T Search Strategy Plot. The peaks are at different stop masses; dashed/solid lines correspond to high/low bino masses. Therefore, S_T is very sensitive to the stop mass, but not to the bino mass. In general, S_T is sensitive to the parent particle mass.
	Efficiency ratio vs Rdxy ("b-ness of events") for muons and electrons.
	ft-fsb for taus with Pt between 40 and 60 GeV (ft is the fake-rate for taus and fsb is inversely proportional to jet activity)
	ft-fsb for taus with Pt between 20 and 40 GeV (ft is the fake-rate for taus and fsb is inversely proportional to jet activity)
	3-muon invariant mass showing asymmetric internal conversion.
	4-lepton mass distribution for low-MET, low-HT ZZ control region
	A comparison of data and simulation for the ST distribution for events with an opposite-sign elecron-muon pair, a dataset dominated by ttbar production, shown in absolute yields.
	MET distribution in WZ control region (3-leptons + 1 on-Z OSSF pair + HT < 200 GeV + Transverse mass between 50 and 100 GeV)
	The transverse mass distribution of events in a data sample enriched in WZ requiring an OSSF pair with invariant mass in the Z-window and 50 GeV < MET < 100 GeV (Linear Scale).
	The transverse mass distribution of events in a data sample enriched in WZ requiring an OSSF pair with invariant mass in the Z-window and 50 GeV < MET < 100 GeV (Log Scale).
	Background breakdown vs ST for 3-leptons + OSSF0 + Tau1 + no b-jets
	Background breakdown vs ST for 3-leptons + OSSF0 + Tau1 + at least 1 b-jets
	Background breakdown vs ST for 3-leptons + OSSF1 + on-Z + Tau0 + no b-jets
	Background breakdown vs ST for 3-leptons + OSSF1 + on-Z + Tau0 + at least 1 b-jet
	Background breakdown vs ST for 3-leptons + OSSF1 + on-Z + Tau1 + no b-jets
	Background breakdown vs ST for 3-leptons + OSSF1 + on-Z + Tau1 + at least 1 b-jet
	Background breakdown vs ST for 3-leptons + OSSF1 + above-Z + Tau0 + no b-jets
	Background breakdown vs ST for 3-leptons + OSSF1 + above-Z + Tau0 + at least 1 b-jet
	Background breakdown vs ST for 3-leptons + OSSF1 + above-Z + Tau1 + no b-jets
	Background breakdown vs ST for 3-leptons + OSSF1 + above-Z + Tau1 + at least 1 b-jet
	Background breakdown vs ST for 3-leptons + OSSF1 + below-Z + Tau0 + no b-jets
	Background breakdown vs ST for 3-leptons + OSSF1 + below-Z + Tau0 + at least 1 b-jet
	Background breakdown vs ST for 3-leptons + OSSF1 + below-Z + Tau1 + no b-jets
	Background breakdown vs ST for 3-leptons + OSSF1 + below-Z + Tau1 + at least 1 b-jet
	Background breakdown vs ST for 4-leptons + OSSF0 + Tau1 + no b-jets
	Background breakdown vs ST for 4-leptons + OSSF0 + Tau1 + at least 1 b-jet
	Background breakdown vs ST for 4-leptons + OSSF1 + on-Z + Tau0 + no b-jets
	Background breakdown vs ST for 4-leptons + OSSF1 + on-Z + Tau0 + at least 1 b-jet
	Background breakdown vs ST for 4-leptons + OSSF1 + on-Z + Tau1 + no b-jets
	Background breakdown vs ST for 4-leptons + OSSF1 + on-Z + Tau1 + at least 1 b-jet
	Background breakdown vs ST for 4-leptons + OSSF1 + off-Z + Tau0 + no b-jets
	Background breakdown vs ST for 4-leptons + OSSF1 + off-Z + Tau0 + at least 1 b-jet
	Background breakdown vs ST for 4-leptons + OSSF1 + off-Z + Tau1 + no b-jets
	Background breakdown vs ST for 4-leptons + OSSF1 + off-Z + Tau1 + at least 1 b-jet
	Background breakdown vs ST for 4-leptons + OSSF2 + on-Z + Tau0 + no b-jets
	Background breakdown vs ST for 4-leptons + OSSF2 + on-Z + Tau0 + at least 1 b-jet
	Background breakdown vs ST for 4-leptons + OSSF2 + off-Z + Tau0 + no b-jets
	Background breakdown vs ST for 4-leptons + OSSF2 + off-Z + Tau0 + at least 1 b-jet