# 3rd International Turkey-Iran Joint Conference on LHC Physics

Jun 10 – 15, 2019
Marmara University Sultanahmet Campus
Europe/Istanbul timezone

## Observation of single top quark production in association with a Z boson at CMS

Jun 10, 2019, 10:00 AM
40m
Marmara University Sultanahmet Campus

İstanbul

### Speaker

Didar Dobur (Ghent University (BE))

### Description

The observation of single top quark production in association with a Z boson and a quark (tZq) will be reported. Events from proton-proton collisions at a center-of-mass energy of 13 TeV containing three charged leptons (either electrons or muons) and at least two jets are analyzed. The data were collected with the CMS detector in 2016 and 2017, and correspond to an integrated luminosity of 77.4 fb^{-1}. The increased integrated luminosity, a multivariate lepton identification, and a redesigned analysis strategy improve significantly the sensitivity of the analysis compared to previous searches for tZq production. The tZq signal is observed with a significance well over five standard deviations. The tZq production cross section is measured with an uncertainty twice as small as achieved by any previous measurement.