# 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!

## Observation of the top quark in proton-nucleus collisions with the CMS experiment at the LHC

May 15, 2018, 5:00 PM
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 Georgios Krintiras (Universite Catholique de Louvain (UCL) (BE))

### Description

The first observation of top quark production in proton-nucleus collisions is reported using proton-lead data collected by the CMS experiment at the CERN LHC at a nucleon-nucleon center-of-mass energy of $\sqrt{s_\text{NN}}$ = 8.16 TeV. The measurement is performed using events with exactly one isolated electron or muon candidate and at least four jets. The data sample corresponds to an integrated luminosity of 174 nb$^-1$ .The significance of the $t\bar{t}$ signal against the background-only hypothesis is above five standard deviations. The measured cross section is $\sigma($t\bar{t}$) = 45 \pm 8$ nb, consistent with predictions from perturbative quantum chromodynamics.

Content type Experiment CMS Presenter name will be specified later