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

TL;DR

This paper analyzes the $ ext{ extphi}_{ ext{eta}}^{*}$ distribution in $Z/ ext{ extgamma}^*$ boson decays using CSS resummation, constraining nonperturbative effects and achieving excellent agreement with Tevatron data.

Contribution

It provides a new constraint on the nonperturbative Gaussian smearing factor in CSS resummation, improving precision in QCD predictions for vector boson production.

Findings

Excellent agreement between data and resummed predictions.

The nonperturbative factor can be used to refine future QCD models.

Uncertainty analysis of scale variations enhances prediction robustness.

Abstract

We summarize a new analysis of the distribution $\phi_{\eta}^{*}$ of charged leptons produced in decays of $Z$ and $\gamma^{*}$ bosons in the Collins-Soper-Sterman (CSS) formalism for transverse momentum resummation. By comparing the $\phi_{\eta}^{*}$ distribution measured at the Tevatron with the resummed CSS cross section with approximate ${\cal O}(\alpha_{s}^{2})$ 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 $\phi_{\eta}^{*}$ 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.