In:
Journal of High Energy Physics, Springer Science and Business Media LLC, Vol. 2018, No. 8 ( 2018-08)
Abstract:
The efficiency to identify jets containing b -hadrons ( b -jets) is measured using a high purity sample of dileptonic top quark-antiquark pairs ( $$ t\overline{t} $$ t 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 $$ \sqrt{s}=13 $$ s = 13 TeV. Two methods are used to extract the efficiency from $$ t\overline{t} $$ t 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.
Type of Medium:
Online Resource
ISSN:
1029-8479
DOI:
10.1007/JHEP08(2018)089
Language:
English
Publisher:
Springer Science and Business Media LLC
Publication Date:
2018
detail.hit.zdb_id:
2027350-2
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