The branching fraction ratio R(Dâ )â ¡B(B¯0â Dâ +Ï -Î½Â¯Ï )/B(B¯0â Dâ +μ-ν¯μ) is measured using a sample of proton-proton collision data corresponding to 3.0fb-1 of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode Ï -â μ-Î½Â¯Î¼Î½Ï . 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 B¯0 decays gives R(Dâ )=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.

Measurement of the Ratio of Branching Fractions B(antiB0 -> D*+ tau- antinu_tau) / B(antiB0 -> D*+ mu- antinu_mu) / Aaij, R., Adeva, B., Adinolfi, M., Affolder, A., Ajaltouni, Z., Akar, S., Albrecht, J., Alessio, F., Alexander, M., Ali, S., Alkhazov, G., Alvarez Cartelle, P., Alves, A.A., Amato, S., Amerio, S., Amhis, Y., An, L., Anderlini, L., Anderson, J., Andreassi, G., et al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 115:11(2015), pp. 111803-111803. [10.1103/PhysRevLett.115.111803]

Measurement of the Ratio of Branching Fractions B(antiB0 -> D*+ tau- antinu_tau) / B(antiB0 -> D*+ mu- antinu_mu)

Bizzeti, A.;
2015

Abstract

The branching fraction ratio R(Dâ )â ¡B(B¯0â Dâ +Ï -Î½Â¯Ï )/B(B¯0â Dâ +μ-ν¯μ) is measured using a sample of proton-proton collision data corresponding to 3.0fb-1 of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode Ï -â μ-Î½Â¯Î¼Î½Ï . 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 B¯0 decays gives R(Dâ )=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
9-set-2015
115
11
111803
111803
Measurement of the Ratio of Branching Fractions B(antiB0 -> D*+ tau- antinu_tau) / B(antiB0 -> D*+ mu- antinu_mu) / Aaij, R., Adeva, B., Adinolfi, M., Affolder, A., Ajaltouni, Z., Akar, S., Albrecht, J., Alessio, F., Alexander, M., Ali, S., Alkhazov, G., Alvarez Cartelle, P., Alves, A.A., Amato, S., Amerio, S., Amhis, Y., An, L., Anderlini, L., Anderson, J., Andreassi, G., et al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - 115:11(2015), pp. 111803-111803. [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.; Alvarez Car...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11380/1156488
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