Search for Stopped Gluinos from pp¯ Collisions at s=1.96TeV

Long-lived, heavy particles are predicted in a number of models beyond the standard model of particle physics. We present the first direct search for such particles’ decays, occurring up to 100 h after their production and not synchronized with an accelerator bunch crossing. We apply the analysis to the gluino (g∼), predicted in split supersymmetry, which after hadronization can become charged and lose enough momentum through ionization to come to rest in dense particle detectors. Approximately 410pb^-1 of pp¯ collisions at s=1.96TeV collected with the D0 detector during Run II of the Fermilab Tevatron collider are analyzed in search of such “stopped gluinos” decaying into a gluon and a neutralino (χ∼₁⁰). Limits are placed on the (gluinocrosssection)×(probabilitytostop)×[BR(g∼→gχ∼₁⁰)] as a function of the gluino and χ∼₁⁰ masses, for gluino lifetimes from 30μs 100h.