Pontificia Universidad Católica de Chile Pontificia Universidad Católica de Chile
Aad G., Abbott B., Abbott D. C., Abud A. A., Abeling K., Abhayasinghe D. K., Abusleme A. (2022)

Measurement of the c-jet mistagging efficiency in tt¯ events using pp collision data at s?=13 TeV collected with the ATLAS detector

Revista : European Physical Journal C
Volumen : 82
Número : 95
Tipo de publicación : ISI Ir a publicación


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.