CDF_2000_S4155203
Measurement of transverse momentum and total cross section of $e^+e^-$ pairs in the Z-boson region of $66 \text{GeV}/c^2 < m_{ee} < 116 \text{GeV}/c^2$ from pbar-p collisions at $\sqrt{s} = 1.8$ TeV, with the Tevatron CDF detector. The $Z$ $p_\perp$, in a fully-factorised picture, is generated by the momentum balance against initial state radiation (ISR) and the primordial/intrinsic $p_\perp$ of the $Z$'s parent partons in the incoming hadrons. The $Z$ $p_\perp$ is important in generator tuning to fix the interplay of ISR and multi-parton interactions (MPI) in generating `underlying event' activity. This analysis is subject to ambiguities in the experimental Z pT definition, since the Rivet implementation reconstructs the Z momentum from the dilepton pair with finite cones for QED bremstrahlung summation, rather than non-portable direct use of the (sometimes absent) Z in the event record.
