Nonperturbative contributions to a resummed leptonic angular distribution in inclusive $Z/γ^*$ boson production

Abstract

We summarize a new analysis of the distribution $ϕ_η^{*}$ of charged leptons produced in decays of $Z$ and $γ^{*}$ bosons in the Collins-Soper-Sterman (CSS) formalism for transverse momentum resummation. By comparing the $ϕ_η^{*}$ distribution measured at the Tevatron with the resummed CSS cross section with approximate ${\cal O}(α_{s}^{2})$ Wilson coefficients, we constrain the magnitude of the nonperturbative Gaussian smearing factor and analyze its uncertainty caused by variations in scale parameters. We find excellent agreement between the $ϕ_η^{*}$ data and our theoretical prediction, provided by the \textsc{ResBos} resummation program. The nonperturbative factor that we obtained can be used to update resummed QCD predictions for precision measurements in inclusive $W$ and $Z$ production and for comparisons to various models of nonperturbative dynamics.

8 pages, 3 figures. Presented at conference: "The QCD Evolution Workshop", May 14-17 2012, Thomas Jefferson National Accelerator Facility, Newport News, VA