A search is presented for free heavy long-lived fractionally charged particles produced in pp collisions at √s=7 TeV. The data sample was recorded by the CMS detector at the LHC and corresponds to an integrated luminosity of 5.0 fb-1. Candidate fractionally charged particles are identified by selecting tracks with associated low charge measurements in the silicon tracking detector. Observations are found to be consistent with expectations for background processes. The results of the search are used to set upper limits on the cross section for pair production of fractionally charged, massive spin-1/2 particles that are neutral under SU(3)C and SU(2)L. We exclude at 95% confidence level such particles with electric charge ±2e/3 with masses below 310 GeV, and those with charge ±e/3 with masses below 140 GeV. © 2013 CERN. Published by the American Physical Society under the terms of the http://creativecommons.org/ licenses/by/3.0/Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.
Chatrchyan, S., Khachatryan, V., Sirunyan, A. M., Tumasyan, A., Adam, W., Aguilo, E., … Swanson, J. (2013). Search for fractionally charged particles in pp collisions at √s=7 TeV. Physical Review D - Particles, Fields, Gravitation and Cosmology, 87(9). https://doi.org/10.1103/PhysRevD.87.092008