Abstract
The branching fraction ratio R(D∗)≡B(B¯0→D∗+τ-ν¯τ)/B(B¯0→D∗+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 τ-→μ-ν¯μντ. 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(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.
Original language | English |
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Article number | 111803 |
Journal | Physical Review Letters |
Volume | 115 |
Issue number | 11 |
DOIs | |
Publication status | Published - 9 Sept 2015 |
Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2015 CERN.
Copyright:
Copyright 2016 Elsevier B.V., All rights reserved.
All Science Journal Classification (ASJC) codes
- General Physics and Astronomy