Linear scaling of lepton charge asymmetry in $W^\pm$ production in ultra-relativistic nuclear collisions

TL;DR

This paper investigates the lepton charge asymmetry in W boson production during ultra-relativistic nuclear collisions, revealing a linear scaling with valence quark asymmetry and matching experimental data.

Contribution

It demonstrates a linear scaling behavior of lepton charge asymmetry with valence quark asymmetry across different nuclear collision systems, providing new constraints for parton distribution functions.

Findings

Reproduces ALICE and ATLAS experimental data.

Identifies a linear scaling of asymmetry with valence quark asymmetry.

Suggests constraints on nuclear parton distribution functions.

Abstract

The lepton charge asymmetry in $W^\pm$ production in the nuclear collisions at $\sqrt{s_{\rm NN}}=5.02$ TeV is investigated with a parton and hadron cascade model PACIAE. Recently published ALICE and the ATLAS data of lepton charge asymmetry are well reproduced. An interesting linear scaling behavior is observed in the lepton charge asymmetry as a function of the collision system valence quark number asymmetry among the different size of nuclear collision systems at $\sqrt{s_{\rm NN}}=5.02$ TeV. This linear scaling behavior may serve as an additional constraint on the PDF (nPDF) extractions.