Measurements of b-jet tagging efficiency with the ATLAS detector using tt¯ events at √s=13 TeV Aaboud, M. Atlas Collaboration Aguilar Saavedra, Juan Antonio The efficiency to identify jets containing b-hadrons (b-jets) is measured using a high purity sample of dileptonic top quark-antiquark pairs (tt¯) 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 s√=13 TeV. Two methods are used to extract the efficiency from tt¯ 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 2019-11-14T10:59:28Z 2019-11-14T10:59:28Z 2018-08-16 info:eu-repo/semantics/article Rimoldi, M., Mullier, G., Miucci, A., Merlassino, C., Haug, S., Weber, M., ... & Ereditato, A. (2018). Measurements of b-jet tagging efficiency with the ATLAS detector using tt events at√ s= 13 TeV. Journal of High Energy Physics, 2018(8). http://hdl.handle.net/10481/57891 10.1007/JHEP08(2018)089 eng http://creativecommons.org/licenses/by/3.0/es/ info:eu-repo/semantics/openAccess Atribución 3.0 España Springer Nature