%0 Journal Article %T Measurements of b-jet tagging efficiency with the ATLAS detector using t(t)over-bar events at root s=13 TeV %A ATLAS Collaboration (Aaboud, M. et al %A Alvarez Piqueras, D. %A Bailey, A. J. %A Barranco Navarro, L. %A Cabrera Urban, S. %A Castillo, F. L. %A Castillo Gimenez, V. %A Cerda Alberich, L. %A Costa, M. J. %A Escobar, C. %A Estrada Pastor, O. %A Ferrer, A. %A Fiorini, L. %A Fuster, J. %A Garcia, C. %A Garcia Navarro, J. E. %A Gonzalez de la Hoz, S. %A Higon-Rodriguez, E. %A Jimenez Pena, J. %A Lacasta, C. %A Lozano Bahilo, J. J. %A Madaffari, D. %A Mamuzic, J. %A Marti-Garcia, S. %A Melini, D. %A Mitsou, V. A. %A Pedraza Lopez, S. %A Rodriguez Bosca, S. %A Rodriguez Rodriguez, D. %A Salt, J. %A Soldevila, U. %A Sanchez, J. %A Valero, A. %A Valls Ferrer, J. A. %A Vos, M. %J Journal of High Energy Physics %D 2018 %V 08 %N 8 %I Springer %@ 1029-8479 %G English %F ATLASCollaborationAaboud_etal2018 %O WOS:000442113300001 %O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=3719), last updated on Tue, 18 Sep 2018 11:50:12 +0000 %X The efficiency to identify jets containing b-hadrons (b-jets) is measured using a high purity sample of dileptonic top quark-antiquark pairs (t (t) over bar) 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 root s = 13 TeV. Two methods are used to extract the efficiency from t (t) over bar 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. %K Hadron-Hadron scattering (experiments) %R 10.1007/JHEP08(2018)089 %U http://arxiv.org/abs/1805.01845 %U https://doi.org/10.1007/JHEP08(2018)089 %P 089-47pp