Linear Scaling of Lepton Charge Asymmetry in W Production in Ultra-Relativistic Nuclear Collisions from PACIAE Model

The lepton charge asymmetry in W-+/- production in the nuclear collisions at root S-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 different sizes of nuclear collision systems at root S-NN = 5:02 TeV. This linear scaling behavior may serve as an additional constraint on the PDF (nPDF) extractions.