Measurement of the cross section of high transverse momentum Z → b¯b production in proton–proton collisions at √s = 8TeVwith the ATLAS detector

Aad, G.; Abbott, B.; Abdallah, J.; Adomeit, Stefanie; Becker, S.; Biebel, Otmar; Bock, Christopher; Bortfeldt, Jonathan; Calfayan, Philippe; Chow, Bonnie Kar Bo; Duckeck, Günter; Ebke, J.; Elmsheuser, Johannes; Heller, C.; Hertenberger, Ralf; Legger, Federica; Lorenz, J.; Mann, A.; Meineck, C.; Mitrevski, Jovan; Nunnemann, Thomas; Rauscher, F.; Ruschke, Alexander; Sanders, Michiel Paul; Schaile, Dorothee; Schieck, J.; Schmitt, C.; Vladoiu, Dan-Nicolae; Walker, R.; Will, J. Z. and Wittkowski, J. (2014): Measurement of the cross section of high transverse momentum Z → b¯b production in proton–proton collisions at √s = 8TeVwith the ATLAS detector. In: Physics Letters B, Vol. 738: pp. 25-43

Abstract

This Letter reports the observation of a high transverse momentum Z→bb signal in proton–proton collisions at √s = 8TeV and the measurement of its production cross section. The data analysed were collected in 2012 with the ATLAS detector at the LHC and correspond to an integrated luminosity of 19.5 fb − 1. The Z → bb decay is reconstructed from a pair of b -tagged jets, clustered with the anti- k t jet algorithm with R = 0.4, that have low angular separation and form a dijet with p T > 200 eV. The signal yield is extracted from a fit to the dijet invariant mass distribution, with the dominant, multi-jet background mass shape estimated by employing a fully data-driven technique that reduces the dependence of the analysis on simulation. The fiducial cross section is determined to be σ fid Z → b ̄ b = 2.02 ± 0.20 (stat.) ± 0.25 (syst.) ± 0.06 (lumi.) pb = 2.02 ± 0.33 pb , in good agreement with next-to-leading-order theoretical predictions.

• Item Type: Journal article
• Form of publication: Publisher's Version
• Keywords: LHC;Boosted b(b)over-bar topologies
• Faculties: Physics
• Subjects: 500 Science > 530 Physics
• ISSN: 0370-2693
• Alliance/National Licence: This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.
• Language: English