Measurement of the ratio of the production cross sections times branching fractions of B± c → J / ψπ± and B± → J / ψK± and B (B± c → J / ψπ±π ±π ∓) / B (B± c → J / ψπ±) in pp collisions at √s = 7 TeV
Baarmand, Marc M.
MetadataShow full item record
Abstract: The ratio of the production cross sections times branching fractions σ(B± c )B(B± c → J/ψπ±) / σ(B±)B(B± → J/ψK±) 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 B± c 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 (τBc )]%. The B± c → J/ψπ±π ±π ∓ 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/ψπ±π ±π ∓)/B(B± c → J/ψπ±) is measured to be 2.55±0.80 (stat)±0.33 (syst)+0.04 −0.01 (τBc ), consistent with the previous LHCb result.