Search for heavy long-lived charged particles in pp collisions at root s=7 TeV


Chatrchyan S., Khachatryan V., Sirunyan A. M., Tumasyan A., Adam W., Bergauer T., ...More

PHYSICS LETTERS B, vol.713, pp.408-433, 2012 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 713
  • Publication Date: 2012
  • Doi Number: 10.1016/j.physletb.2012.06.023
  • Journal Name: PHYSICS LETTERS B
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.408-433
  • Keywords: CMS, Physics, ATLAS DETECTOR
  • Çukurova University Affiliated: Yes

Abstract

The result of a search for heavy long-lived charged particles produced in pp collisions at root s = 7 TeV at the LHC is described. The data sample has been collected using the CMS detector and corresponds to an integrated luminosity of 5.0 fb(-1). The inner tracking detectors are used to define a sample of events containing tracks with high momentum and high ionization energy loss. A second sample of events, which have high-momentum tracks satisfying muon identification requirements in addition to meeting high-ionization and long time-of-flight requirements, is analyzed independently. In both cases, the results are consistent with the expected background estimated from data. The results are used to establish cross section limits as a function of mass within the context of models with long-lived gluinos, scalar top quarks and scalar taus. Cross section limits on hyper-meson particles, containing new elementary long-lived hyper-quarks predicted by a vector-like confinement model, are also presented. Lower limits at 95% confidence level on the mass of gluinos (scalar top quarks) are found to be 1098 (737) GeV/c(2). A limit of 928 (626) GeV/c(2) is set for a gluinos (scalar top quark) that hadronizes into a neutral bound state before reaching the muon detectors. The lower mass limit for a pair produced scalar tau is found to be 223 GeV/c(2). Mass limits for a hyper-kaon are placed at 484, 602, and 747 GeV/c(2) for hyper-rho masses of 800, 1200, and 1600 GeV/c(2), respectively. (c) 2012 CERN. Published by Elsevier B.V. All rights reserved.