Measurement of the Ratio of Branching Fractions B (B[subscript c][superscript +] → J/ψτ[superscript +]ν[superscript τ]) / B (B[subscript c][superscript +] → J/ψμ[superscript +]ν[subscript μ]
A measurement is reported of the ratio of branching fractions R(J/ψ)=B(B[subscript c][superscript +]→J/ψτ[superscript +]ν[subscript τ])/B(B[subscript c][superscript +]→J/ψμ[superscript +]ν[subscript μ]), where the τ[superscript +] lepton is identified in the decay mode τ[superscript +]→μ[superscript...
| Main Authors: | , , , , |
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| Other Authors: | |
| Format: | Article |
| Published: |
American Physical Society
2018
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| Online Access: | http://hdl.handle.net/1721.1/119151 https://orcid.org/0000-0002-3684-1560 https://orcid.org/0000-0001-5534-1732 https://orcid.org/0000-0001-8285-3346 |
| Summary: | A measurement is reported of the ratio of branching fractions R(J/ψ)=B(B[subscript c][superscript +]→J/ψτ[superscript +]ν[subscript τ])/B(B[subscript c][superscript +]→J/ψμ[superscript +]ν[subscript μ]), where the τ[superscript +] lepton is identified in the decay mode τ[superscript +]→μ[superscript +]ν[subscript μ]ν[superscript τ]. This analysis uses a sample of proton-proton collision data corresponding to 3.0 fb[superscript -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[subscript c][superscript +]→J/ψτ[superscript +]ν[subscript τ] 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. |
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