Measurement of the C-jet Mistagging Efficiency in Tt[over-bar] Events Using Pp Collision Data at [square Root]s
Author: [Study Group] ATLAS Collaboration CERN
Publisher:
Published: 2022
Total Pages: 0
ISBN-13:
DOWNLOAD EBOOKAbstract: A technique is presented to measure the efficiency with which c-jets are mistagged as b-jets (mistagging efficiency) using tt ̄ events, where one of the W bosons decays into an electron or muon and a neutrino and the other decays into a quark-antiquark pair. The measurement utilises the relatively large and known W→cs branching ratio, which allows a measurement to be made in an inclusive c-jet sample. The data sample used was collected by the ATLAS detector at s√=13 TeV and corresponds to an integrated luminosity of 139 fb−1. Events are reconstructed using a kinematic likelihood technique which selects the mapping between jets and tt ̄ decay products that yields the highest likelihood value. The distribution of the b-tagging discriminant for jets from the hadronic W decays in data is compared with that in simulation to extract the mistagging efficiency as a function of jet transverse momentum. The total uncertainties are in the range 3-17%. The measurements generally agree with those in simulation but there are some differences in the region corresponding to the most stringent b-jet tagging requirement