Jul 15 – 19, 2019
US/Eastern timezone

Electroweak boson measurements with ALICE

Jul 18, 2019, 4:30 PM
20m
2213 A Chair : Timothy Hobbs

2213 A Chair : Timothy Hobbs

PDFs/alpha_S/Soft PDFs/Soft/Alpha_S I

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)

Presentation materials