Revisiting the new-physics interpretation of the b → cτν data
Abstract
We revisit the status of the new-physics interpretations of the anomalies in semileptonic B decays in light of the new data reported by Belle on the lepton-universality ratios RD(*) using the semileptonic tag and on the longitudinal polarization of the D* in B → D*τν, FLD ∗. The preferred solutions involve new left-handed currents or tensor contributions. Interpretations with pure right-handed currents are disfavored by the LHC data, while pure scalar models are disfavored by the upper limits derived either from the LHC or from the Bc lifetime. The observable FLD ∗ also gives an important constraint leading to the exclusion of large regions of parameter space. Finally, we investigate the sensitivity of different observables to the various scenarios and conclude that a measurement of the tau polarization in the decay mode B → Dτν would effectively discriminate among them.
- Publication:
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Journal of High Energy Physics
- Pub Date:
- December 2019
- DOI:
- 10.1007/JHEP12(2019)065
- arXiv:
- arXiv:1905.08498
- Bibcode:
- 2019JHEP...12..065S
- Keywords:
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- Beyond Standard Model;
- Heavy Quark Physics;
- High Energy Physics - Phenomenology;
- High Energy Physics - Experiment
- E-Print:
- matches publised version