Flavour anomalies after the R K ∗ measurement
Abstract
The LHCb measurement of the μ/e ratio R K ∗ indicates a deficit with respect to the Standard Model prediction, supporting earlier hints of lepton universality violation observed in the R K ratio. We show that the R K and R K ∗ ratios alone constrain the chiralities of the states contributing to these anomalies, and we find deviations from the Standard Model at the 4 σ level. This conclusion is further corroborated by hints from the theoretically challenging b → sμ + μ - distributions. Theoretical interpretations in terms of Z', lepto-quarks, loop mediators, and composite dynamics are discussed. We highlight their distinctive features in terms of the chirality and flavour structures relevant to the observed anomalies.
- Publication:
-
Journal of High Energy Physics
- Pub Date:
- September 2017
- DOI:
- 10.1007/JHEP09(2017)010
- arXiv:
- arXiv:1704.05438
- Bibcode:
- 2017JHEP...09..010D
- Keywords:
-
- Beyond Standard Model;
- Technicolor and Composite Models;
- High Energy Physics - Phenomenology
- E-Print:
- Updated including the Moriond 2019 data from LHCb and Belle. 37 pages, 11 figures