A measurement is presented of the inclusive cross-section for b-jet production in association with a Z boson in pp collisions at a centre-of-mass energy of root s = 7 TeV. The analysis uses the data sample collected by the ATLAS experiment in 2010, corresponding to an integrated luminosity of approximately 36 pb(-1). The event selection requires a Z boson decaying into high P-T electrons or muons, and at least one b-jet, identified by its displaced vertex, with transverse momentum p(T) > 25 GeV and rapidity vertical bar y vertical bar < 2.1. After subtraction of background processes, the yield is extracted from the vertex mass distribution of the candidate b-jets. The ratio of this cross-section to the inclusive Z cross-section (the average number of b-jets per Z event) is also measured. Both results are found to be in good agreement with perturbative QCD predictions at next-to-leading order. (C) 2011 CERN. Published by Elsevier B.V. All rights reserved. RI della Volpe, Domenico/B-4482-2012; Wolter, Marcin/A-7412-2012; valente, paolo/A-6640-2010; O'Shea, Val/G-1279-2010; Doyle, Anthony/C-5889-2009; Ferrando, James/A-9192-2012; Li, Xuefei/C-3861-2012; Buttar, Craig/D-3706-2011; Pina, Joao /C-4391-2012; Takai, Helio/C-3301-2012; St.Denis, Richard/C-8997-2012; Jones, Roger/H-5578-2011; Robson, Aidan/G-1087-2011; Britton, David/F-2602-2010; Smirnova, Lidia/D-8089-2012; Sivoklokov, Sergey/D-8150-2012; Smirnov, Sergei/F-1014-2011; Gladilin, Leonid/B-5226-2011; Barreiro, Fernando/D-9808-2012; Kramarenko, Victor/E-1781-2012; Prokoshin, Fedor/E-2795-2012; Alexa, Calin/F-6345-2010; Gutierrez, Phillip/C-1161-2011; Pacheco Pages, Andres/C-5353-2011; Moorhead, Gareth/B-6634-2009; Livan, Michele/D-7531-2012; Petrucci, Fabrizio/G-8348-2012; Wemans, Andre/A-6738-2012; Fabbri, Laura/H-3442-2012; Kurashige, Hisaya/H-4916-2012; Villa, Mauro/C-9883-2009; Kuzhir, Polina/H-8653-2012; Delmastro, Marco/I-5599-2012

Measurement of the cross-section for b-jets produced in association with a Z boson at root s=7 TeV with the ATLAS detector ATLAS Collaboration

CALDERINI, GIOVANNI;CAVASINNI, VINCENZO;