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

Authors

CMS Collaboration
Ekaterina Avdeeva, University of Nebraska-LincolnFollow
Kenneth A. Bloom, University of Nebraska-LincolnFollow
S. Bose, University of Nebraska-LincolnFollow
J. Butt, University of Nebraska-Lincoln
Daniel R. Claes, University of Nebraska-LincolnFollow
Aaron Dominguez, University of Nebraska-LincolnFollow
Michael Eads, University of Nebraska-LincolnFollow
P. Jindal, University of Nebraska-Lincoln
J. Keller, University of Nebraska-LincolnFollow
Ilya Kravchenko, University of Nebraska-LincolnFollow
J. Lazo-Flores, University of Nebraska-LincolnFollow
H. Malbouisson, University of Nebraska-Lincoln
Sudhir Malik, University of Nebraska-LincolnFollow
Gregory Snow, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

2012

Citation

Physics Letters B 713 (2012) 408–433; http://dx.doi.org/10.1016/j.physletb.2012.06.023

Abstract

The result of a search for heavy long-lived charged particles produced in pp collisions at √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 longlived 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/c². A limit of 928 (626) GeV/c² is set for a gluino (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/c2. Mass limits for a hyper-kaon are placed at 484, 602, and 747 GeV/c² for hyper-ρ masses of 800, 1200, and 1600 GeV/c², respectively.