Abstract
A measurement is reported of the ratio of branching fractions ℛ(J/ψ)=ℬ(Bc+→J/ψτ+ντ)/ℬ(Bc+→J/ψμ+νμ), where the τ+ lepton is identified in the decay mode τ+→μ+νμv̅τ. 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 Bc+→J/ψτ+ντ at a significance of 3 standard deviations corrected for systematic uncertainty, and the ratio of the branching fractions is measured to be ℛ(J/ψ)=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.
Original language | English |
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Article number | 121801 |
Number of pages | 10 |
Journal | Physical Review Letters |
Volume | 120 |
Issue number | 12 |
DOIs | |
Publication status | Published - 23 Mar 2018 |
ASJC Scopus subject areas
- General Physics and Astronomy