11th International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions

Electroweak bosons produced in hard-scattering processes at the early stage of the collision, are efficient probes of the initial state of the collision. While the W measurements in pp collisions are a stringent test of perturbative QCD-based calculations and production mechanisms, they can constrain the nuclear parton distribution functions in p-Pb and Pb-Pb collisions.

Electroweak bosons are studied with ALICE in pp collisions at $\sqrt s$ = 13 TeV, p-Pb collisions at $\sqrt{s_{\rm NN}}$ = 8.16 TeV and Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 5.02 TeV via their leptonic decays in the muon and electron channels at forward rapidity ($-4.0< \eta < -2.5$) and midrapidity ($\vert \eta \vert < 0.8$), respectively. The observations in p-Pb and Pb-Pb collisions at forward rapidity give access to low Bjorken-$x$ values, a phase-space region poorly constrained by heavy-ion experiments.

The latest W-boson results concerning differential measurements of the normalised production yields, production cross sections, nuclear modification factors and lepton-charge asymmetry as a function of rapidity, transverse momentum, collision centrality and charged-particle multiplicity are presented. The production of W bosons in association with hadrons as a function of the charged-particle multiplicity in pp collisions is reported as well. Comparisons with model calculations are discussed.