Abstract: The ratio of the production cross sections times branching fractions (s(B±c)B(B±c?J/?p±))/(s(B±)B(B±?J/?K±)) is studied in proton-proton collisions at a center-of-mass energy of 7 TeV with the CMS detector at the LHC. The kinematic region investigated requires Bc± and B± mesons with transverse momentum pT > 15 GeV and rapidity |y| < 1.6. The data sample corresponds to an integrated luminosity of 5.1 fb-1. The ratio is determined to be [0.48±0.05(stat)±0.03(syst)±0.05 (tBc)]%. The Bc±???J/?p±p±p± decay is also observed in the same data sample. Using a model-independent method developed to measure the efficiency given the presence of resonant behaviour in the three-pion system, the ratio of the branching fractions B(B±c?J/?p±p±p±)/B(B±c?J/?p±) is measured to be 2.55±0.80(stat)±0.33(syst)+0.04-0.01(tBc), consistent with the previous LHCb result.

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