# Measurement of the c-jet mistagging efficiency in t(t)over-bar events using pp collision data at root s=13 TeV collected with the ATLAS detector

Aad, G, Abbott, B, Abbott, DC, Abud, A Abed, Abeling, K, Abhayasinghe, DK, Abidi, SH, Aboulhorma, A, Abramowicz, H, Abreu, H
et al (show 2890 more authors) (2022) Measurement of the c-jet mistagging efficiency in t(t)over-bar events using pp collision data at root s=13 TeV collected with the ATLAS detector. EUROPEAN PHYSICAL JOURNAL C, 82 (1). 95-.

Access the full-text of this item by clicking on the Open Access link.

## Abstract

A technique is presented to measure the efficiency with which $c$-jets are mistagged as b-jets (mistagging efficiency) using $t\bar{t}$ 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 $W\to cs$ 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 $\sqrt{s} = 13$ 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 $t\bar{t}$ 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.

Item Type: Article 39 pages in total, author list starting page 23, 6 figures, 2 tables, published in EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/FTAG-2020-08 hep-ex, hep-ex Faculty of Science and Engineering > School of Physical Sciences Symplectic Admin 07 Feb 2022 09:00 18 Jan 2023 21:13 10.1140/epjc/s10052-021-09843-w https://link.springer.com/article/10.1140%2Fepjc%2... https://livrepository.liverpool.ac.uk/id/eprint/3148380