The branching fraction ratio R(D*) ≡ B(anti-B0 → D*+ τ− anti-ντ) / B(anti-B0 → D*+ μ− anti-νμ) is measured 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− anti-νμ ντ. The semitauonic decay is sensitive to contributions from non-standard-model particles that preferentially couple to the third generation of fermions, in particular, Higgs-like charged scalars. A multidimensional fit to kinematic distributions of the candidate anti-B0 decays gives R(D*) = 0.336 ± 0.027(stat) ± 0.030(syst). This result, which is the first measurement of this quantity at a hadron collider, is 2.1 standard deviations larger than the value expected from lepton universality in the standard model.

Aaij, R., Adeva, B., Adinolfi, M., Affolder, A., Ajaltouni, Z., Akar, S., et al. (2015). Measurement of the Ratio of Branching Fractions B(anti-B0 → D*+ τ− anti-ντ) / B(anti-B0 → D*+ μ− anti-νμ). PHYSICAL REVIEW LETTERS, 115(11), 1-10 [10.1103/PhysRevLett.115.111803].

Measurement of the Ratio of Branching Fractions B(anti-B0 → D*+ τ− anti-ντ) / B(anti-B0 → D*+ μ− anti-νμ)

Capriotti, L.;CARBONE, ANGELO;FERRARI, FABIO;GALLI, DOMENICO;MUSSINI, MANUEL;PATRIGNANI, CLAUDIA;PERAZZINI, STEFANO;VAGNONI, VINCENZO MARIA;ZANGOLI, MARIA;ZUCCHELLI, STEFANO
2015

Abstract

The branching fraction ratio R(D*) ≡ B(anti-B0 → D*+ τ− anti-ντ) / B(anti-B0 → D*+ μ− anti-νμ) is measured 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− anti-νμ ντ. The semitauonic decay is sensitive to contributions from non-standard-model particles that preferentially couple to the third generation of fermions, in particular, Higgs-like charged scalars. A multidimensional fit to kinematic distributions of the candidate anti-B0 decays gives R(D*) = 0.336 ± 0.027(stat) ± 0.030(syst). This result, which is the first measurement of this quantity at a hadron collider, is 2.1 standard deviations larger than the value expected from lepton universality in the standard model.
2015
Aaij, R., Adeva, B., Adinolfi, M., Affolder, A., Ajaltouni, Z., Akar, S., et al. (2015). Measurement of the Ratio of Branching Fractions B(anti-B0 → D*+ τ− anti-ντ) / B(anti-B0 → D*+ μ− anti-νμ). PHYSICAL REVIEW LETTERS, 115(11), 1-10 [10.1103/PhysRevLett.115.111803].
Aaij, R.; Adeva, B.; Adinolfi, M.; Affolder, A.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Cartelle, P...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11585/515569
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