Search for Long-Lived Charged Massive Particles with the D0 Detector

We search for long-lived charged massive particles using $1.1{\mathrm{fb}}^{-1}$ of data collected by the D0 detector at the Fermilab Tevatron $p\overline{p}$ Collider. Time-of-flight information is used to search for pair produced long-lived tau sleptons, gauginolike charginos, and Higgsino-like charginos. We find no evidence of a signal and set 95% C.L. cross section upper limits for staus, which vary from 0.31 to 0.04 pb for stau masses between 60 and 300 GeV. We also set lower mass limits of 206 GeV (171 GeV) for pair produced charged gauginos (Higgsinos).

Figure 1

Distributions of (a) the invariant mass and (b) speed significance product, for the simulated background (solid line), the 300 GeV stau signal (dotted line), and the data (as dots) passing the selection criteria.

Figure 2

The observed (dots) and expected (solid line) 95% cross section limits, the NLO production cross section (dashed line), and NLO cross section uncertainty (barely visible shaded band) as a function of (a) stau mass for stau pair production, (b) chargino mass for pair produced gauginolike charginos, and (c) chargino mass for pair produced Higgsino-like charginos.