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 < 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 −0..04 01 (τBc), consistent with the previous LHCb result.
Measurement of the ratio of the production cross sections times branching fractions of Bc^\pm → J/ψπ^\pm and B^\pm → J/ψK^\pm and Br(Bc^\pm → J/ψπ^\pm π^\pmπ^\pm)/ Br(Bc^\pm → J/ψπ^\pm) in pp collisions at sqrt(s) = 7 TeV
Sola, V.;AMAPANE, Nicola Carlo;ARGIRO', Stefano;BELLAN, Riccardo;COSTA, Marco;MIGLIORE, Ernesto;MONACO, Vincenzo;OBERTINO, Maria Margherita;ROMERO, Alessandra;SACCHI, Roberto;SOLANO, Ada Maria;COVARELLI, Roberto;
2015-01-01
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 < 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 −0..04 01 (τBc), consistent with the previous LHCb result.File | Dimensione | Formato | |
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