CERN Accelerating science

ATLAS Slides
Report number	ATL-PHYS-SLIDE-2021-521
Title	Top quark properties overview (asymmetries, CP violation, spin correlations, FCNC) at the LHC
Author(s)	Kempster, Jacob Julian (University of Birmingham (GB))
Corporate author(s)	The ATLAS collaboration
Collaboration	ATLAS Collaboration
Submitted to	22nd Particles and Nuclei International Conference (PANIC 2021), Lisbon, Portugal, 5 - 10 Sep 2021
Submitted by	[email protected] on 13 Sep 2021
Subject category	Particle Physics - Experiment
Accelerator/Facility, Experiment	CERN LHC ; ATLAS
Free keywords	PANIC ; top ; quark ; properties ; LHC ; spin ; polarisation ; charge ; energy ; asymmetry ; CP ; CPV ; violation ; ATLAS ; CMS ; lepton ; flavour ; universality ; FCNC ; flavor ; changing ; neutral ; currents ; tt ; l+jets ; lepton+jets ; dilepton ; tZq ; tHq ; LFU ; TOP
Abstract	The remarkably large integrated luminosity collected by the ATLAS and CMS detectors during Run2 in proton–proton collisions at a centre-of-mass of 13 TeV allows to use the large sample of top quark events to explore a variety of properties of top quark production and decay and to probe the presence on new physics that might break well established symmetries or manifest itself in rare processes. Measurements of are presented for all three components of the top-quark and antiquark polarisation vectors in t-channel single-top-quark production, normalised differential cross sections as a function of the charged lepton angles. Resulting limits on the complex Wilson coefficient of the dimension-six O_{tW} operator in the framework of an effective field theory are also reported. A precise measurement of the ratio between the probability for the W boson decay to tau to the probability for its decay to a muon testing the universality of the W-lepton coupling is illustrated. Finally searches for FCNC interactions between the top quark, a charm- or an up-quark and bosons or gluons are also reported.