ATLAS b-jet identification performance and efficiency measurement with tt¯ events in pp collisions at s√=13 TeV

Date

2019

Authors

Aad, G.
Abbott, B.
Abbott, D.C.
Abed Abud, A.
Abeling, K.
Abhayasinghe, D.K.
Abidi, S.H.
AbouZeid, O.S.
Abraham, N.L.
Abramowicz, H.

Journal Title

Journal ISSN

Volume Title

Publisher

The European Physical Journal C

Abstract

The algorithms used by the ATLAS Collaboration during Run 2 of the Large Hadron Collider to identify jets containing b-hadrons are presented. The performance of the algorithms is evaluated in the simulation and the efficiency with which these algorithms identify jets containing b-hadrons is measured in collision data. The measurement uses a likelihood-based method in a sample highly enriched in tt¯ events. The topology of the t→Wb decays is exploited to simultaneously measure both the jet flavour composition of the sample and the efficiency in a transverse momentum range from 20 to 600 GeV. The efficiency measurement is subsequently compared with that predicted by the simulation. The data used in this measurement, corresponding to a total integrated luminosity of 80.5 fb−1, were collected in proton–proton collisions during the years 2015–2017 at a centre-of-mass energy s√= 13 TeV. By simultaneously extracting both the efficiency and jet flavour composition, this measurement significantly improves the precision compared to previous results, with uncertainties ranging from 1 to 8% depending on the jet transverse momentum.

Description

Keywords

Citation

Aad, G., Abbott, B., Abbott, D. C., Abed Abud, A., Abeling, K., Abhayasinghe, D. K., … Zwalinski, L. (2019). ATLAS b-jet identification performance and efficiency measurement with tt events in pp collisions at s√=13TeV. The European Physical Journal C, 79(11). https://doi.org/10.1140/epjc/s10052-019-7450-8