The ratios of branching fractions R(D*) ≡ B(anti-B → D* τ− anti-ν_τ) / B(anti-B → D* μ− anti-ν_μ) and R(D0) ≡ B(B− → D0 τ− anti-ν_τ) / B(B− → D0 μ− anti-ν_μ) are measured, assuming isospin symmetry, using a sample of proton-proton collision data corresponding to 3.0 fb^−1 of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode τ− → μ− ν_τ anti-ν_μ. The measured values are R(D*) = 0.281 ± 0.018 ± 0.024 and R(D0) = 0.441 ± 0.060 ± 0.066 , where the first uncertainty is statistical and the second is systematic. The correlation between these measurements is ρ = −0.43. The results are consistent with the current average of these quantities and are at a combined 1.9 standard deviations from the predictions based on lepton flavor universality in the standard model.

Aaij, R., Abdelmotteleb, A.S.W., Abellan Beteta, C., Abudinén, F., Ackernley, T., Adeva, B., et al. (2023). Measurement of the Ratios of Branching Fractions R(D*) and R(D0). PHYSICAL REVIEW LETTERS, 131(11), 1-13 [10.1103/PhysRevLett.131.111802].

Measurement of the Ratios of Branching Fractions R(D*) and R(D0)

Carbone, A;Ferrari, F;Galli, D;Manuzzi, D;Patrignani, C;Spedicato, E;Villa, A;Zucchelli, S;
2023

Abstract

The ratios of branching fractions R(D*) ≡ B(anti-B → D* τ− anti-ν_τ) / B(anti-B → D* μ− anti-ν_μ) and R(D0) ≡ B(B− → D0 τ− anti-ν_τ) / B(B− → D0 μ− anti-ν_μ) are measured, assuming isospin symmetry, using a sample of proton-proton collision data corresponding to 3.0 fb^−1 of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode τ− → μ− ν_τ anti-ν_μ. The measured values are R(D*) = 0.281 ± 0.018 ± 0.024 and R(D0) = 0.441 ± 0.060 ± 0.066 , where the first uncertainty is statistical and the second is systematic. The correlation between these measurements is ρ = −0.43. The results are consistent with the current average of these quantities and are at a combined 1.9 standard deviations from the predictions based on lepton flavor universality in the standard model.
2023
Aaij, R., Abdelmotteleb, A.S.W., Abellan Beteta, C., Abudinén, F., Ackernley, T., Adeva, B., et al. (2023). Measurement of the Ratios of Branching Fractions R(D*) and R(D0). PHYSICAL REVIEW LETTERS, 131(11), 1-13 [10.1103/PhysRevLett.131.111802].
Aaij, R; Abdelmotteleb, A S W; Abellan Beteta, C; Abudinén, F; Ackernley, T; Adeva, B; Adinolfi, M; Adlarson, P; Afsharnia, H; Agapopoulou, C; Aidala,...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/953269
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