# ICHEP 2022

Jul 6 – 13, 2022
Bologna, Italy
Europe/Rome timezone

## Measurements of jet and soft activity in √sNN = 200 GeV p+Au collisions at STAR

Jul 8, 2022, 7:05 PM
1h 25m
Bologna, Italy

#### Bologna, Italy

Palazzo della Cultura e dei Congressi
Poster Heavy Ions

### Speaker

Veronica Verkest (Wayne State University)

### Description

Proton-ion collisions at the LHC and RHIC have yielded unexpected trends, notably in measurements of jet nuclear modification factors as a function of event activity (EA). Recent preliminary measurements from STAR in p+Au collisions at $\sqrt{s_{{\rm NN}}}=200$ GeV demonstrate inherent correlations between high-$Q^{2}$ parton scatterings and EA measured at backward (Au-going) rapidities or underlying event (UE) at mid-rapidity. The measurements at STAR disfavor jet quenching as an explanation for the suppression of jet yield observed in high-EA collisions. This leads to an opportunity to probe the early stages of the proton ion collisions. In this talk, we show correlations of backward-rapidity EA with mid-rapidity UE, as well as measurements of EA-dependent modifications to charged hadron spectra and jets. In particular, we present measurements of the UE for various EA selections and discuss its kinematic dependence on jet pseudorapidity ($\eta$) and transverse momentum ($p_{{\rm T}}$) as a means of examining the correlation between initial hard scatterings and soft processes. We also investigate the EA dependence of high-$p_{{\rm T}}$ hadron and jet properties---including fully corrected ungroomed and SoftDrop groomed jet substructure observables---to study the impact of initial and final state effects.

In-person participation No

### Primary author

Veronica Verkest (Wayne State University)

### Presentation materials

 Verkest_ICHEP2022_vid.mp4 vverkest_ICHEP2022_v4.pdf