Revisiting the new-physics interpretation of the b → cτν data

Shi, Rui-Xiang; Geng, Li-Sheng; Grinstein, Benjamín; Jäger, Sebastian; Martin Camalich, Jorge
Bibliographical reference

Journal of High Energy Physics

Advertised on:
12
2019
Number of authors
5
IAC number of authors
1
Citations
111
Refereed citations
83
Description
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.
Type