First Measurement of the Angular Coefficients of Drell-Yan $e^{+}e^{-}$ pairs in the Z Mass Region from $p\bar{p}$ Collisions at $\sqrt{s}$ = 1.96 TeV

TL;DR

This paper presents the first measurement of angular coefficients of Drell-Yan electron pairs in the Z mass region from proton-antiproton collisions at 1.96 TeV, providing insights into Z boson production mechanisms.

Contribution

It provides the first experimental measurement of angular distributions of Drell-Yan pairs at Tevatron energies, testing QCD predictions and the Lam-Tung relation.

Findings

Angular distributions agree with Lam-Tung relation.

At high transverse momentum, Z bosons are produced via quark-antiquark and quark-gluon processes.

Results support spin-1 gluon and QCD-based production models.

Abstract

We report on the first measurement of the angular distributions of final state electrons in $p\bar{p}\to \gamma^{*}/Z\to e^{+}e^{-}+X$ events produced in the $Z$ boson mass region at $\sqrt{s}=1.96$ TeV. The data sample collected by the CDF II detector for this result corresponds to 2.1 fb$^{-1}$ of integrated luminosity. The angular distributions are studied as a function of the transverse momentum of the electron-positron pair and show good agreement with the Lam-Tung relation, consistent with a spin-1 description of the gluon, and demonstrate that at high values of the transverse momentum, $Z$ bosons are produced via quark anti-quark annihilation and quark-gluon Compton processes.