Evidence for simultaneous production of $J/ψ$ and $Υ$ mesons

D0 Collaboration

Paper

Evidence for simultaneous production of $J/ψ$ and $Υ$ mesons

Abstract

We report evidence for the simultaneous production of

and

mesons in 8.1 fb

of data collected at

1.96 TeV by the D0 experiment at the Fermilab

Tevatron Collider. Events with these characteristics are expected to be produced predominantly by gluon-gluon interactions. In this analysis, we extract the effective cross section characterizing the initial parton spatial distribution,