CP3 results on CERN Courier
The CMS detector at the LHC is used to search for yet unobserved heavy (mass >100 GeV/c^2), long-lived (lifetime > 1 ns), electrically charged particles, called generically HSCPs. HSCPs can be distinguished from Standard Model particles by exploiting their unique signature: very high momentum and low velocity. These features are a consequence of their high mass and the relatively limited LHC collision energy. Two experimental techniques are used to identify these particles: the measurement of the ionization energy loss rate using the all-silicon tracker detector and the time-of-flight measurement with the muon detectors. UCL members have developed the ionization energy loss identification technique and lead the analysis since 2010, when the first HSCP paper became one of the first published LHC search papers. Updated results, using the 2011 dataset, were then published and, more recently, a comprehensive paper including also searches for fractional and multiply-charged particles has been published using the full CMS Run-1 dataset. The analysis, which is very inclusive, doesn't find evidence of HSCP. It currently excludes, among various models, the existence of quasi-stable gluinos, predicted by split supersymmetry, and Drell-Yan produced staus with masses lower than about 1.3 TeV and 350 GeV, respectively. These and the other limits set by the analysis are the most stringent to date. These results have also been reinterpreted to exclude a significant region of the pMSSM parameter space. The CMS HSCP papers total todate more than 150 citations.
Reference url: http://cds.cern.ch/record/1690595/files/CERNCourier2014Apr-digitaledition.pdf