First Results on the Search for Stopped Gluinos in pp collisions at sqrt s = 7 TeV

We present the first results of a search for long-lived gluinos which have stopped in the Compact Muon Solenoid (CMS) detector after being produced in 7 TeV $pp$ collisions from CERN's Large Hadron Collider (LHC). We looked for the subsequent decay of these particles during time intervals where there were no $pp$ collisions in the CMS experiment. In particular, we searched for decays during gaps between crossings in the LHC beam structure. We recorded such decays with a dedicated calorimeter trigger. In a dataset with a peak instantaneous luminosity of $1.3 \times 10^{30} {\rm cm}^{-2} {\rm s}^{-1}$, an integrated luminosity of 203 - 232 nb$^{-1}$ depending on the gluino lifetime, and a search interval corresponding to 115 hours of LHC operation, no significant excess above background was observed. In the absence of a signal, we set a limit at 95\%~C.L. on gluino pair production over 14 orders of magnitude of gluino lifetime. This result extends existing limits from the Tevatron. For a mass difference $m_{\tilde{g}}-M_{\tilde{\chi}^0_1} >100$ GeV, assuming BR($\tilde{g} \rightarrow g\tilde{\chi}^0_1$) = 100\%, we are able to exclude lifetimes from 75 ns - 6 $\mu$s for $m_{\tilde{g}} = 200$ GeV/$c^2$. Furthermore we exclude gluino masses $m_{\tilde{g}} < 229$ GeV/$c^2$ with a lifetime of 200~ns using a time-profile analysis and $m_{\tilde{g}} < 225$ GeV/$c^2$ with a lifetime of $2.6~\mu$s in a counting experiment.