The Angular Coefficients and $A_{fb}$ of Drell-Yan $e^{+}e^{-}$ Pairs in the Z Mass Region from $p\bar{p}$ Collision at $\sqrt{s}$ = 1.96 TeV

TL;DR

This paper measures angular coefficients and forward-backward asymmetry of Drell-Yan dielectron pairs in proton-antiproton collisions at 1.96 TeV, testing theoretical relations and providing insights into gluon spin properties.

Contribution

It presents the first detailed measurement of angular coefficients and $A_{fb}$ in this energy regime, including tests of the Lam-Tung relation for gluon spin characterization.

Findings

Angular coefficients vary with dielectron transverse momentum.

Measured $A_{fb}$ agrees with Standard Model predictions.

Lam-Tung relation holds within experimental uncertainties.

Abstract

We report on the measurement of angular coefficients and the forward and backward asymmetry ($A_{fb}$) of Drell-Yan dielectron pairs from $p\bar{p}$ collision at $\sqrt{s}$ = 1.96 TeV. The angular distributions are studied as a function of the transverse momentum of dielectron pair and $A_{fb}$ is measured using the event counting method. The Lam-Tung ($A_{0} - A_{2} = 0$) relation which is only valid for a spin-1 description of the gluon is also tested.