Measurement of the B c ± production cross section in pp¯ collisions at √s = 1.96 TeV

Abstract

We describe a measurement of the ratio of the cross sections times branching fractions of the B+c meson in the decay mode B+c → J/ψ µ+ν to the B+ meson in the decay mode B+ → J/ψ K+ in proton-antiproton collisions at center-of-mass energy √s = 1.96 TeV. The measurement is based on the complete CDF Run II data set, which comes from an integrated luminosity of 8.7 −1. The ratio of the production cross sections times branching fractions for B + c and B + mesons with momentum transverse to the beam greater than 6 GeV/c and rapidity magnitude smaller than 0.6 is 0.211 ± 0.012 (stat)+0.021−0.020 (syst). Using the known B + → J/ψ K+ branching fraction, the known B + production cross section, and a selection of the predicted B + c → J/ψ µ+ν branching fractions, the range for the total B+c production cross section is estimated.