Measurements of b-jet tagging efficiency with the ATLAS detector using t(t)over-bar events at root s=13 TeV



Aaboud, M, Aad, G, Abbott, B, Abdinov, O, Abeloos, B, Abhayasinghe, DK, Abidi, SH, AbouZeid, OS, Abraham, NL, Abramowicz, H
et al (show 2903 more authors) (2018) Measurements of b-jet tagging efficiency with the ATLAS detector using t(t)over-bar events at root s=13 TeV. JOURNAL OF HIGH ENERGY PHYSICS, 08 (8). 89-.

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Abstract

The efficiency to identify jets containing $b$-hadrons ($b$-jets) is measured using a high purity sample of dileptonic top quark-antiquark pairs ($t\bar{t}$) selected from the 36.1 fb$^{-1}$ of data collected by the ATLAS detector in 2015 and 2016 from proton-proton collisions produced by the Large Hadron Collider at a centre-of-mass energy $\sqrt{s}=13$ TeV. Two methods are used to extract the efficiency from $t\bar{t}$ events, a combinatorial likelihood approach and a tag-and-probe method. A boosted decision tree, not using $b$-tagging information, is used to select events in which two $b$-jets are present, which reduces the dominant uncertainty in the modelling of the flavour of the jets. The efficiency is extracted for jets in a transverse momentum range from 20 to 300 GeV, with data-to-simulation scale factors calculated by comparing the efficiency measured using collision data to that predicted by the simulation. The two methods give compatible results, and achieve a similar level of precision, measuring data-to-simulation scale factors close to unity with uncertainties ranging from 2% to 12% depending on the jet transverse momentum.

Item Type: Article
Additional Information: 49 pages in total, author list starting page 33, 12 figures, 6 tables, published in JHEP. All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/PERF-2016-05/
Uncontrolled Keywords: Hadron-Hadron scattering (experiments)
Depositing User: Symplectic Admin
Date Deposited: 10 Sep 2018 06:46
Last Modified: 19 Jan 2023 01:25
DOI: 10.1007/JHEP08(2018)089
Open Access URL: https://link.springer.com/article/10.1007/JHEP08(2...
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URI: https://livrepository.liverpool.ac.uk/id/eprint/3025938