A search for charged massive long-lived particles at D0

Abstract

Results are presented on a search for charged massive long-lived particles (CMLLPs), based on 5.2 fb − 1 of integrated luminosity collected with the D0 detector at the Fermilab Tevatron $p\!\bar{p}$ collider. This search selects events in which one or more particles are reconstructed as muons but their speed and ionization energy loss (dE/dx) are different from muons produced in beam–beam collisions. CMLLPs have been predicted by several theories of physics beyond the Standard Model. In this search we exclude pair-produced long-lived gaugino-like charginos with masses below 251 GeV and higgsino-like charginos with masses below 230 GeV at 95% CL, as well as long-lived stop quarks with masses below 265 GeV. We place cross-section limits on long-lived staus as 0.04 to 0.006 pb for stau masses in the range 100 to 300 GeV.