par Aaron, Francise;Favart, Laurent ;Ceccopieri, Federico ;Hreus, Tomas ; [et al.]
Référence European Physical Journal C. Particles and Fields, C72, page (2047), 1205.2495
Publication Publié, 2012
Article révisé par les pairs
Résumé : Measurements of cross sections for beauty and charm events with dijets and a muon in the photoproduction regime at HERA are presented. The data were collected with the H1 detector and correspond to an integrated luminosity of 179 pb-1. Events with dijets of transverse momentum PTjet1 > 7 GeV and PTjet2 > 6 GeV in the pseudorapidity range -1.5 < ηjet < 2.5 in the laboratory frame are selected in the kinematic region of photon virtuality Q2 < 2.5 GeV2 and inelasticity 0.2 < y < 0.8. One of the two selected jets must be associated to a muon with PTμ > 2.5 GeV in the pseudorapidity range -1.3 < η μ < 1.5. The fractions of beauty and charm events are determined using the impact parameters of the muon tracks with respect to the primary vertex and their transverse momentum relative to the axis of the associated jet. Both variables are reconstructed using the H1 vertex detector. The measurements are in agreement with QCD predictions at leading and next-to-leading order. © 2012 The Author(s).