skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Search for R-parity violating decays of a top squark in proton–proton collisions at $$\sqrt{s} =$$ 8 TeV

Abstract

The results of a search for a supersymmetric partner of the top quark (top squark), pair-produced in proton-proton collisions at $$\sqrt{s} =$$ 8 TeV, are presented. The search, which focuses on R-parity violating, chargino-mediated decays of the top squark, is performed in final states with low missing transverse momentum, two oppositely charged electrons or muons, and at least five jets. The analysis uses a data sample corresponding to an integrated luminosity of 19.7 fb$$^{-1}$$ collected with the CMS detector at the LHC in 2012. The data are found to be in agreement with the standard model expectation, and upper limits are placed on the top squark pair production cross section at 95% confidence level. Assuming a 100% branching fraction for the top squark decay chain, $$ \mathrm{ \tilde{t} \to t \tilde{\chi}^{\pm}_1,\, \tilde{\chi}^{\pm}_1 \to \ell^\pm+jj } $$, top squark masses less than 890 (1000) GeV for the electron (muon) channel are excluded for the first time in models with a single nonzero R-parity violating coupling $$\lambda^{\prime}_{ijk}$$ $$(i,j,k \leq 2)$$, where $i,j,k$ correspond to the three generations.

Authors:
 [1]
  1. et al.
Publication Date:
Research Org.:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Argonne National Lab. (ANL), Argonne, IL (United States); Princeton Univ., NJ (United States)
Sponsoring Org.:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
OSTI Identifier:
1259196
Report Number(s):
FERMILAB-PUB-16-059-CMS; CMS-EXO-14-013; CERN-PH-EP-2016-005; CERN-EP-2016-005; arXiv:1602.04334
Journal ID: ISSN 0370-2693; 1421645
Grant/Contract Number:
AC02-07CH11359; SC0007968
Resource Type:
Journal Article: Published Article
Journal Name:
Physics Letters. Section B
Additional Journal Information:
Journal Volume: 760; Journal Issue: C; Journal ID: ISSN 0370-2693
Publisher:
Elsevier
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; CMS; physics; supersymmetry; leptons; low missing transverse energy

Citation Formats

Khachatryan, Vardan. Search for R-parity violating decays of a top squark in proton–proton collisions at $\sqrt{s} =$ 8 TeV. United States: N. p., 2016. Web. doi:10.1016/j.physletb.2016.06.039.
Khachatryan, Vardan. Search for R-parity violating decays of a top squark in proton–proton collisions at $\sqrt{s} =$ 8 TeV. United States. doi:10.1016/j.physletb.2016.06.039.
Khachatryan, Vardan. 2016. "Search for R-parity violating decays of a top squark in proton–proton collisions at $\sqrt{s} =$ 8 TeV". United States. doi:10.1016/j.physletb.2016.06.039.
@article{osti_1259196,
title = {Search for R-parity violating decays of a top squark in proton–proton collisions at $\sqrt{s} =$ 8 TeV},
author = {Khachatryan, Vardan},
abstractNote = {The results of a search for a supersymmetric partner of the top quark (top squark), pair-produced in proton-proton collisions at $\sqrt{s} =$ 8 TeV, are presented. The search, which focuses on R-parity violating, chargino-mediated decays of the top squark, is performed in final states with low missing transverse momentum, two oppositely charged electrons or muons, and at least five jets. The analysis uses a data sample corresponding to an integrated luminosity of 19.7 fb$^{-1}$ collected with the CMS detector at the LHC in 2012. The data are found to be in agreement with the standard model expectation, and upper limits are placed on the top squark pair production cross section at 95% confidence level. Assuming a 100% branching fraction for the top squark decay chain, $ \mathrm{ \tilde{t} \to t \tilde{\chi}^{\pm}_1,\, \tilde{\chi}^{\pm}_1 \to \ell^\pm+jj } $, top squark masses less than 890 (1000) GeV for the electron (muon) channel are excluded for the first time in models with a single nonzero R-parity violating coupling $\lambda^{\prime}_{ijk}$ $(i,j,k \leq 2)$, where $i,j,k$ correspond to the three generations.},
doi = {10.1016/j.physletb.2016.06.039},
journal = {Physics Letters. Section B},
number = C,
volume = 760,
place = {United States},
year = 2016,
month = 6
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1016/j.physletb.2016.06.039

Citation Metrics:
Cited by: 1work
Citation information provided by
Web of Science

Save / Share:
  • The results of a search for a supersymmetric partner of the top quark (top squark), pair-produced in proton-proton collisions atmore » $$\sqrt{s} =$$ 8 TeV, are presented. The search, which focuses on R-parity violating, chargino-mediated decays of the top squark, is performed in final states with low missing transverse momentum, two oppositely charged electrons or muons, and at least five jets. The analysis uses a data sample corresponding to an integrated luminosity of 19.7 fb$$^{-1}$$ collected with the CMS detector at the LHC in 2012. The data are found to be in agreement with the standard model expectation, and upper limits are placed on the top squark pair production cross section at 95% confidence level. Assuming a 100% branching fraction for the top squark decay chain, $$ \mathrm{ \tilde{t} \to t \tilde{\chi}^{\pm}_1,\, \tilde{\chi}^{\pm}_1 \to \ell^\pm+jj } $$, top squark masses less than 890 (1000) GeV for the electron (muon) channel are excluded for the first time in models with a single nonzero R-parity violating coupling $$\lambda^{\prime}_{ijk}$$ $$(i,j,k \leq 2)$$, where $i,j,k$ correspond to the three generations.« less
  • Here, the results of a search for a supersymmetric partner of the top quark (top squark), pair-produced in proton–proton collisions at √s = 8 TeV, are presented. The search, which focuses on R-parity violating, chargino-mediated decays of the top squark, is performed in final states with low missing transverse momentum, two oppositely charged electrons or muons, and at least five jets. The analysis uses a data sample corresponding to an integrated luminosity of 19.7 fb –1 collected with the CMS detector at the LHC in 2012. The data are found to be in agreement with the standard model expectation, andmore » upper limits are placed on the top squark pair production cross section at 95% confidence level. Assuming a 100% branching fraction for the top squark decay chain, t ~→tχ ~ 1 ±~ 1 ± → ℓ ± + jj, top squark masses less than 890 (1000) GeV for the electron (muon) channel are excluded for the first time in models with a single nonzero R-parity violating coupling λ ijk'(i,j,k ≤ 2), where i,j,k correspond to the three generations.« less
  • A search for the pair production of top squarks, each with R -parity-violating decays into two Standard Model quarks, is performed using 17.4 fb -1 of √s=8 TeV proton-proton collision data recorded by the ATLAS experiment at the LHC. Each top squark is assumed to decay to a b- and an s-quark, leading to four quarks in the final state. Background discrimination is achieved with the use of b-tagging and selections on the mass and substructure of large-radius jets, providing sensitivity to top squark masses as low as 100 GeV. Finally, no evidence of an excess beyond the Standard Model background prediction is observed and top squarks decaying tomore » $$\overline{b}$$$\overline{s}$$ are excluded for top squark masses in the range 100 ≤ m $$\overline{t}$$ ≤ 315 GeV at 95% confidence level.« less
  • A search for the pair production of top squarks, each with R-parity-violating decays into two Standard Model quarks, is performed using 17.4 fb -1 of √s = 8 TeV proton-proton collision data recorded by the ATLAS experiment at the LHC. Each top squark is assumed to decay to a b- and an s-quark, leading to four quarks in the final state. Background discrimination is achieved with the use of b-tagging and selections on the mass and substructure of large-radius jets, providing sensitivity to top squark masses as low as 100 GeV. No evidence of an excess beyond the Standard Modelmore » background prediction is observed and top squarks decaying to b¯ s¯ are excluded for top squark masses in the range 100 ≤ m t ≤ 315 GeV at 95% confidence level.« less