Nuclear modification of vector boson production in proton-lead collisions at the LHC

TL;DR

This paper predicts how vector boson production in proton-lead collisions at the LHC is modified by nuclear effects, offering tests for nuclear shadowing and insights into QCD multiple scattering.

Contribution

It provides theoretical predictions for nuclear modification factors and transverse momentum broadening in proton-lead collisions, highlighting signatures of nuclear anti-shadowing and parton multiple scattering.

Findings

Nuclear modification factor of Z^0 can test nuclear anti-shadowing.

Transverse momentum broadening differs significantly between heavy quarkonium and W/Z^0.

Predictions serve as benchmarks for upcoming LHC measurements.

Abstract

In anticipating the upcoming proton-lead run at the LHC in the near future, we present predictions for the nuclear modification factor of transverse momentum spectrum of $Z^0$ production and transverse momentum broadening of vector boson ($J/\psi$, $\Upsilon$, $W/Z^0$) production in proton-lead collisions at $\sqrt{s}=5$ TeV, respectively. We find that the measurement of nuclear modification factor of $Z^0$ production provides a clean and unambiguous test of the nuclear anti-shadowing proposed in the recent EPS09. In addition, the dramatic difference in transverse momentum broadening between the heavy quarkonium and $W/Z^0$ production could be a signature prediction of QCD parton multiple scattering, and it provides valuable informations on color neutralization of a produced heavy quark pair when it transmutes into a physical quarkonium.