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 → W b 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.

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

De Castro , S.;Fabbri , L.;Gabrielli , A.;Rinaldi , L.;Semprini Cesari , N.;Sioli , M.;Villa , M.;Zoccoli , A.;Bellagamba , L.;Boscherini , D.;Giacobbe , B.;Polini , A.;Sbarra , C.;Franchini , M.;Mengarelli , A.;Romano , M.;Valentinetti , S.;Biondi , S.;Fabbri , F.;Lasagni Manghi , F;Massa , L.;Ucchielli , G.;Vittori , C.;Cabras , G.;Giangiacomi , N.;
2019

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 → W b 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.
De Castro , S. ; Fabbri , L. ; Gabrielli , A. ; Rinaldi , L. ; Semprini Cesari , N. ; Sioli , M. ; Villa , M. ; Zoccoli , A. ; Bellagamba , L. ; Boscherini , D. ; Bruni , A. ; Bruni , G. ; D’Amen , G. ; Giacobbe , B. ; Polini , A. ; Sbarra , C. ; Sidoti , A. ; Spighi , R. ; Franchini , M. ; Mengarelli , A. ; Romano , M. ; Valentinetti , S. ; Alberghi , G. L. ; Biondi , S. ; Fabbri , F. ; Lasagni Manghi , F; Massa , L. ; Ucchielli , G. ; Vittori , C. ; Alfonsi , F: ; Cabras , G. ; Cervelli , A. ; Giangiacomi , N. ; Negrini , M. ; ATLAS collaboration
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11585/724765
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