Heavy quarks and prompt leptons inp―pcollider jets

(i) Large-transverse-momentum $\bar{p}p$ events at $\sqrt{s}=540\mathrm{}$ GeV are dominated by two-jet production; the cross section is compatible with the predictions of perturbative QCD. (ii) Large-$p_T$ jets are rich in charm particles. We investigate the implications of these experimental observations. We find a source of heavy quarks and associated prompt leptons which could totally dominate yields conventionally computed from perturbative QCD and which, more importantly, leads to totally different event characteristics. For example, events where both jets contain a heavy-quark fragment ($c\bar{c}+c\bar{c}$, $c\bar{c}+b\bar{b}$, or $b\bar{b}+b\bar{b}$) are the origin of opposite- and same-sign lepton pairs with equal probability. The dileptons are accompanied by four strange particles and occasionally conceal their jet origin by trigger bias. They form a possible source of the "anomalous" dilepton events recently observed by the UA1 experiment.