Truncated QCD shower calculation of heavy-quark production in pp-bar collisions with B0-B-bar 0 mixing.

Abstract

Characteristics of $W$ production are well described by a parton-shower approximation, based solely on the $q\overline{q}\ensuremath{\rightarrow}\mathrm{Wg}$ subprocess with a low-${p}_{T}$ cutoff chosen to reproduce the total cross section through order ${\ensuremath{\alpha}}_{s}$. We apply this approach to $Q\overline{Q}$ production from the 2\ensuremath{\rightarrow} 3-parton subprocesses in $p\overline{p}$ collisions. The results agree with CERN dimuon events for a ${B}^{0}\ensuremath{-}{\overline{B}}^{0}$ mixing parameter $\ensuremath{\epsilon}\ensuremath{\gtrsim}0.1$, which is at the ${e}^{+}{e}^{\ensuremath{-}}$ experimental limit and larger than standard-model expectations.