Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt{s}=7 TeV with the ATLAS detector
Abstract
The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons ( b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt{s} = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20< p T<400 GeV and rapidity in the range | y|<2.1. The boverline{b}-dijet cross-section is measured as a function of the dijet invariant mass in the range 110< m jj<760 GeV, the azimuthal angle difference between the two jets and the angular variable χ in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured boverline{b}-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.
- Publication:
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European Physical Journal C
- Pub Date:
- December 2011
- DOI:
- 10.1140/epjc/s10052-011-1846-4
- arXiv:
- arXiv:1109.6833
- Bibcode:
- 2011EPJC...71.1846A
- Keywords:
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- High Energy Physics - Experiment
- E-Print:
- 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal C