Nuclear dependences of azimuthal asymmetries in the Drell-Yan process

TL;DR

This paper investigates how nuclear environments affect azimuthal asymmetries in Drell-Yan processes, revealing suppression effects through a Gaussian broadening model and numerical analysis.

Contribution

It introduces a convolution approach using the maximal two-gluon correlation approximation to relate nuclear and nucleon transverse momentum dependent quark distributions.

Findings

Averaged azimuthal asymmetries are suppressed in nuclear collisions.

The Gaussian broadening model effectively describes nuclear dependence.

Numerical results support the suppression of asymmetries in nuclei.

Abstract

We study nuclear dependences of azimuthal asymmetries in the Drell-Yan lepton pair production in nucleon-nucleus collisions with polarized nucleons.We use the "maximal two-gluon correlation approximation", so that we can relate the transverse momentum dependent quark distribution in a nucleus to that in a nucleon by a convolution with a Gaussian broadening.We use the Gaussian ansatz for the transverse momentum dependence of such quark distribution functions,and obtain the numerical results for the nuclear dependences.These results show that the averaged azimuthal asymmetries are suppressed.