Speaker
Diego Stocco
(Subatech)
Description
W and Z bosons are created in the hard scattering processes occurring in the initial stage of heavy-ion collisions and they are insensitive to the presence of a strongly-interactive medium. This makes them a clean probe of the initial-state effects of the collision, such as the nuclear modification of the parton distribution functions (PDFs).
The measurement of the electroweak boson production in p-Pb and Pb-Pb collisions at the LHC provides constraints on the nPDFs of the (anti-)quarks in a phase-space region that is poorly constrained by previous experiments.
ALICE measures the electroweak boson production in the muonic decay channel in p-Pb and Pb-Pb collisions at large rapidities ($2.5 < y_{lab} < 4$ in the laboratory reference frame). These measurements are complementary to those performed by ATLAS and CMS at mid-rapidity.
In this talk, we review the measurements in heavy-ion collisions, with a focus on the most recent results. In particular, the rapidity and centrality dependence of the Z-boson production in Pb-Pb collisions at a center of mass energy per nucleon of $\sqrt{s_{\rm NN}} = 5.02$ TeV will be presented and the status of the analysis of the 2018 data sample will be discussed.
The new results on Z-boson production in p-Pb collisions at $\sqrt{s_{\rm NN}} = 8.16$ TeV will be discussed as well.
The results will be compared to calculations obtained with or without including the nuclear modifications of the PDFs.
Primary author
Diego Stocco
(Subatech)