B Meson Decays

We briefly review recent developments in the study of the quantum nature of flavor mixing; in particular, the attention will be devoted to neutrino and neutral meson oscillations. We employ Leggett-Garg type inequalities and no-signaling-in-time conditions to probe the intrinsic quantumness of such a physical manifestation, showing how the analysis is not affected by the wave-packet spreading (for neutrinos) and the intrinsic particle instability (for mesons).

Finite energy QCD sum rules with Legendre polynomial integration kernels are used to determine the heavy meson decay constant f Bc , and revisit f B and f Bs. Results exhibit excellent stability in a wide range of values of the integration radius in the complex squared energy plane, and of the order of the Legendre polynomial. Results are f Bc = 528 ± 19 MeV, f B = 186 ± 14 MeV, and f Bs = 222 ± 12 MeV.

A search for the X(4140) state in B + → J/ψφK + decays is performed with 0.37 fb −1 of pp collisions at √ s = 7 TeV collected by the LHCb experiment. No evidence for this state is found, in 2.4 σ disagreement with a measurement by CDF. An upper limit on its production rate is set, B(B + → X(4140)K +) × B(X(4140) → J/ψ φ)/B(B + → J/ψ φK +) < 0.

A peaking structure in the J/psi phi mass spectrum near threshold is observed in B(+/-) to J/psi phi K(+/-) decays, produced in pp collisions at sqrt(s) = 7 TeV collected with the CMS detector at the LHC. The data sample, selected on the basis of the dimuon decay mode of the J/psi, corresponds to an integrated luminosity of 5.2 inverse femtobarns. Fitting the structure to an S-wave relativistic Breit-Wigner lineshape above a three-body phase-space nonresonant component gives a signal statistical significance exceeding five standard deviations. The fitted mass and width values are m=4148.0 +/-2.4 (stat.) +/-6.3 (syst.) MeV and Gamma=28-11+15 (stat.) +/-19 (syst.) MeV, respectively. Evidence for an additional peaking structure at higher J/psi phi mass is also reported.

J= mesons have been reconstructed from their decay t o + and e + e , using the data collected by the DELPHI experiment during 1991 and 1992 at the LEP collider. From about 1 million hadronic Z decays 153 17 J= were found, 5.4 2.3 0 were obtained in the channel J= (! +) + and 6.4 2.7 c in the channel J= (! +). As the dominant source of J= mesons is from b quarks, the following branching ratios: Br(b!J= X) = (1 : 12 0:12 (stat.) 0:10 (syst.))% Br(b! 0 X) = (0 : 48 0:22 (stat.) 0:10 (syst.))% Br(b! c1 X) = (1 : 4 0 : 6 (stat.) +0:4 0:2 (syst.))% were measured. From the proper time distribution of the J= sample, the average lifetime o f b-hadrons decaying into J= was found to be: B = 1 : 50 +0:24 0:21 (stat.) 0:03 (syst.) ps: A search for completely reconstructed B meson decays to nal states including a J= gave a signal of 15 5 e v ents.

The decay B + → ψ(2S)φ(1020)K + is observed for the first time using data collected from pp collisions at √ s = 8 TeV by the CMS experiment at the LHC, corresponding to an integrated luminosity of 19.6 fb −1. The branching fraction of this decay is measured, using the mode B + → ψ(2S)K + as normalization, to be (4.0 ± 0.4 (stat) ± 0.6 (syst) ± 0.2 (B)) × 10 −6 , where the third uncertainty is from the measured branching fraction of the normalization channel.

A peaking structure in the J/psi phi mass spectrum near threshold is observed in B(+/-) to J/psi phi K(+/-) decays, produced in pp collisions at sqrt(s) = 7 TeV collected with the CMS detector at the LHC. The data sample, selected on the basis of the dimuon decay mode of the J/psi, corresponds to an integrated luminosity of 5.2 inverse femtobarns. Fitting the structure to an S-wave relativistic Breit-Wigner lineshape above a three-body phase-space nonresonant component gives a signal statistical significance exceeding five standard deviations. The fitted mass and width values are m=4148.0 +/-2.4 (stat.) +/-6.3 (syst.) MeV and Gamma=28 -11+15 (stat.) +/-19 (syst.) MeV, respectively. Evidence for an additional peaking structure at higher J/psi phi mass is also reported.

A peaking structure in the J/psi phi mass spectrum near threshold is observed in B(+/-) to J/psi phi K(+/-) decays, produced in pp collisions at sqrt(s) = 7 TeV collected with the CMS detector at the LHC. The data sample, selected on the basis of the dimuon decay mode of the J/psi, corresponds to an integrated luminosity of 5.2 inverse femtobarns. Fitting the structure to an S-wave relativistic Breit-Wigner lineshape above a three-body phase-space nonresonant component gives a signal statistical significance exceeding five standard deviations. The fitted mass and width values are m=4148.0 +/-2.4 (stat.) +/-6.3 (syst.) MeV and Gamma=28 -11+15 (stat.) +/-19 (syst.) MeV, respectively. Evidence for an additional peaking structure at higher J/psi phi mass is also reported.

A peaking structure in the J/psi phi mass spectrum near threshold is observed in B(+/-) to J/psi phi K(+/-) decays, produced in pp collisions at sqrt(s) = 7 TeV collected with the CMS detector at the LHC. The data sample, selected on the basis of the dimuon decay mode of the J/psi, corresponds to an integrated luminosity of 5.2 inverse femtobarns. Fitting the structure to an S-wave relativistic Breit-Wigner lineshape above a three-body phase-space nonresonant component gives a signal statistical significance exceeding five standard deviations. The fitted mass and width values are m=4148.0 +/-2.4 (stat.) +/-6.3 (syst.) MeV and Gamma=28-11+15 (stat.) +/-19 (syst.) MeV, respectively. Evidence for an additional peaking structure at higher J/psi phi mass is also reported.

Abstract: The decay constants of the pseudoscalar mesons B and Bs are evaluated from QCD sum rules for the pseudoscalar two-point function. Recently calculated perturbative three-loop QCD corrections are incorporated into the sum rule. An analysis in terms of the bottom quark pole mass turns out to be unreliable due to large higher order corrections. On the contrary, in the MS scheme the radiative corrections are under good theoretical control and a reliable determination of fB and fBs becomes feasible. Including variations of all input parameters within reasonable ranges, our final results for the pseudoscalar meson decay constants are fB = 197±23 MeV and fBs = 232±25 MeV. Employing additional information on the product √ BBfB from global fits to the unitarity triangle, we are in a position to also extract the B-meson B-parameter BB = 1.25 ± 0.41. Our results are very compatible with analogous determinations of the above quantities in lattice QCD, albeit with smaller errors in the ...

The decay B + → ψ(2S)φ(1020)K + is observed for the first time using data collected from pp collisions at √ s = 8 TeV by the CMS experiment at the LHC, corresponding to an integrated luminosity of 19.6 fb −1. The branching fraction of this decay is measured, using the mode B + → ψ(2S)K + as normalization, to be (4.0 ± 0.4 (stat) ± 0.6 (syst) ± 0.2 (B)) × 10 −6 , where the third uncertainty is from the measured branching fraction of the normalization channel.

A search for the X(4140) state in B+ to J/psi phi K+ decays is performed with 0.37 fb-1 of pp collisions at sqrt(s)=7 TeV collected by the LHCb experiment. No evidence for this state is found, in 2.4 sigma disagreement with a measurement by CDF. An upper limit on its production rate is set, BR(B+ to X(4140) K+) BR(X(4140) to J/psi phi) / BR(B+ to J/psi phi K+) &lt; 0.07 at 90% confidence level.

Observation of the decay B + → ψ(2S)φ(1020)K + in pp collisions at √ s = 8 TeV .The CMS Collaboration CERN, Switzerland The decay B + → ψ(2S)φ(1020)K + is observed for the first time using data collected from pp collisions at √ s = 8 TeV by the CMS experiment at the LHC, corresponding to an integrated luminosity of 19.6 fb −1. The branching fraction of this decay is measured, using the mode B + → ψ(2S)K + as normalization, to be (4.0 ± 0.4 (stat) ± 0.6 (syst) ± 0.2 (B)) × 10 −6 , where the third uncertainty is from the measured branching fraction of the normalization channel.