Measurement of the relative B^±_c/B^± production cross section with the ATLAS detector at √s = 8 TeV

The total cross section and differential cross sections for the production of B±c mesons, times their branching fraction to J/ψπ^±, are measured relative to those for the production of B± mesons, times their branching fraction to J/ψK^±. The data used for this study correspond to an integrated luminosity of 20.3 fb⁻¹ of pp collisions recorded by the ATLAS detector at the Large Hadron Collider in 2012 at a center-of-mass energy of √s = 8 TeV. The measurement is performed differentially in bins of transverse momentum p_T for 13 GeV <p_T (B^±_c)<22 GeV  and p_T (B^±_c) >22 GeV in bins of rapidity y for|y|<0.75 and 0.75<|y|<2.3 The relative cross section times branching fraction for the full range p_T>13 GeV and |y|<2.3 is (0.34±0.04_stat+^0.06_−0.02sys±0.01_lifetime)%. The differential measurements suggest that the production cross section of the B^±_c decreases faster with pT than the production cross section of the B±, while no significant dependence on rapidity is observed.