# Quark Matter 2018

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

## Measurement of the Underlying Event in pp collisions at√s = 13 TeV with the ALICE experiment at the LHC

15 May 2018, 17:00
2h 40m
First floor and third floor (Palazzo del Casinò)

### First floor and third floor

#### Palazzo del Casinò

Poster Initial state physics and approach to equilibrium

### Speaker

Mr Xiaowen Ren (Central China Normal University CCNU (CN))

### Description

Large In LHC RUN 2, the Large Hadron Collider restarted with a centre-of-mass energy increase of around 60% with respect to the end of the LHC RUN 1, in which the highest energy of pp collision is 7 TeV. At this new energy, 13 TeV in pp collision, it is absolutely essential to restudy the general features of the pp interaction, in particular the soft or semi-hard bulk of particles that form the Underlying Event, which is defined to be the complementary activity with respect to the leading interaction.

Measurement of the Underlying Event allows us to access fundamental information on the particle production. This has important consequences for lepton and photon isolation, and also for jet calibration.

In order to estimate the contributions to the Underlying Event, we present a characterization of the event properties focusing on the orthogonal plane with respect to the beam direction: the primary charged particle with the highest transverse momentum is used to give the energy scale of the interaction, Underlying Event activity is measured as a function of this energy scale. Primary charged particle and energy densities are measured in different azimuthal regions with respect to the leading charged particle. Three track $p_{T}$ cuts are considered for all the tracks: 1, 0.5 and 0.15 GeV/c.

In this poster, the first results on Underlying Event measurement in pp collisions at $\sqrt{s}$ = 13 TeV with the ALICE experiment will be presented.

Centralised submission by Collaboration Presenter name will be specified later Experiment

### Primary author

Mr Xiaowen Ren (Central China Normal University CCNU (CN))