TY  - JOUR
AU  - LHCb Collaboration (Aaij, R. et al
AU  - Garcia Martin, L. M.
AU  - Henry, L.
AU  - Martinez-Vidal, F.
AU  - Oyanguren, A.
AU  - Remon Alepuz, C.
AU  - Ruiz Valls, P.
AU  - Ruiz Vidal, J.
AU  - Sanchez Mayordomo, C.
PY  - 2018
DA  - 2018//
TI  - Measurement of the Ratio of Branching Fractions B(B-c(+) -> J/psi tau(+)nu(tau))/B(B-c(+) -> J/psi mu(+)nu(mu))
T2  - Phys. Rev. Lett.
JO  - Physical Review Letters
SP  - 121801 - 10pp
VL  - 120
IS  - 12
PB  - Amer Physical Soc
AB  - A measurement is reported of the ratio of branching fractions R(J/psi) = B(B-c(+) -> J/psi tau(+)nu(tau))/B(B-c(+) -> J/psi mu(+)nu(mu)), where the tau(+) lepton is identified in the decay mode tthorn tau(+) -> mu(+)nu(mu)(nu) over bar (tau). This analysis uses a sample of proton-proton collision data corresponding to 3.0 fb(-1) of integrated luminosity recorded with the LHCb experiment at center-of-mass energies of 7 and 8 TeV. A signal is found for the decay B-c(+) -> J/psi tau(+)nu(tau) at a significance of 3 standard deviations corrected for systematic uncertainty, and the ratio of the branching fractions is measured to be R(J/psi) = 0.71 +/- 0.17(stat) +/- 0.18(syst). This result lies within 2 standard deviations above the range of central values currently predicted by the standard model.
SN  - 0031-9007
UR  - http://arxiv.org/abs/1711.05623
UR  - https://doi.org/10.1103/PhysRevLett.120.121801
DO  - 10.1103/PhysRevLett.120.121801
LA  - English
N1  - WOS:000428167200007
ID  - LHCbCollaborationAaij_etal2018
ER  -