# Initial Stages 2021

Jan 10 – 15, 2021
Weizmann Institute of Science
Asia/Jerusalem timezone
See you at IS2023 in Copenhagen in June 2023

## Production of $W$, $Z$, and charged hadrons in Pb+Pb collisions with the ATLAS detector

Jan 14, 2021, 5:10 PM
20m
Andrea's room 2 (vDLCC)

### Andrea's room 2

#### vDLCC

oral The initial stages of heavy-ion collisions

### Speaker

Iwona Grabowska-Bold (AGH University of Science and Technology (PL))

### Description

Measurements of $W^{\pm}$, $Z$, and charged-hadron production in Pb+Pb collisions at $\sqrt{s_{NN}}=5.02$ TeV
are presented using data recorded by the ATLAS experiment at the LHC in 2015 corresponding to a total integrated luminosity of 0.49\,nb${}^{-1}$.
The the electro-weak (EW) bosons are reconstructed in both the electron and muon decay channels.
The EW boson yields measured in Pb+Pb collisions, normalised by the total number of minimum-bias events and the mean nuclear thickness function, are compared with similar measurements made in pp collisions at the same centre-of-mass energy.
The results are compared with predictions based on next-to-leading-order calculations with CT14 parton distribution functions as well as with nuclear modifications to PDFs implemented in EPPS16.
The central and mid-central collisions are consistent with the calculations and
a small excess above the calculations is observed in the peripheral collisions.
The inclusive charge-hadron yield in Pb+Pb, Xe+Xe and p+Pb collisions
is also normalized by the mean nuclear thickness function and is also compared against the yields of charged hadrons in pp collisions.
The comparison of the nuclear modification of EW bosons and charged particles in central and
periperhal Pb+Pb collisions will provide constraints on the relative importance of initial- and final-state effects in these measurements.

### Primary author

Iwona Grabowska-Bold (AGH University of Science and Technology (PL))

### Presentation materials

 InitialStages2021-EWBosonsAtlas-012021.pdf Recording