# Quark Matter 2018

May 13 – 19, 2018
Venice, Italy
Europe/Zurich timezone
The organisers warmly thank all participants for such a lively QM2018! See you in China in 2019!

## Charged particle nuclear modification factors in pPb, PbPb and XeXe collisions with the CMS experiment

May 15, 2018, 9:20 AM
20m
Sala Perla, 1st Floor (Palazzo del Casinò)

### Sala Perla, 1st Floor

#### Palazzo del Casinò

Parallel Talk Jet modifications and high-pT hadrons

### Speaker

Austin Alan Baty (Massachusetts Inst. of Technology (US))

### Description

The spectra of charged particles in XeXe and PbPb collisions at $\sqrt{s_{NN}} = 5.44$ TeV and $\sqrt{s_{NN}} = 5.02$ TeV, respectively, are presented in six ranges of collision centrality. The PbPb nuclear modification factor is constructed with a measured pp reference, and the XeXe nuclear modification factor is formed with an extrapolated pp reference. Both are found to be heavily suppressed in the most central collisions. The path-length and collision-energy dependence of parton energy loss are probed by comparing these two systems of differing size. The data are also compared to various theoretical models, as well as previous measurements at lower collision energies. The pPb nuclear modification factor is constructed using a measured pp reference and is seen to be slightly above unity for the highest transverse momentum probed by the measurement. This illustrates contributions due to initial-state effects, such as anti-shadowing in the nuclear parton distribution functions.

Content type Experiment Presenter name already specified CMS