B-anomalies related to leptons and lepton flavour universality violation

TL;DR

This paper reviews recent experimental anomalies involving muons and taus that challenge the Standard Model, exploring potential models that could simultaneously explain these deviations and their implications for lepton flavor universality.

Contribution

It provides a comprehensive review of the latest anomalies related to leptons and discusses models that could explain multiple deviations simultaneously.

Findings

Multiple experiments observe deviations from the SM in lepton flavor transitions.

Anomalies are primarily associated with muons and taus, not electrons.

Potential models can address several anomalies at once.

Abstract

Several experiments observed deviations from the Standard Model (SM) in the flavour sector: LHCb found a $4-5\,\sigma$ discrepancy compared to the SM in $b\to s\mu^+\mu^-$ transitions (recently supported by an Belle analysis) and CMS reported a non-zero measurement of $h\to\mu\tau$ with a significance of $2.4\,\sigma$. Furthermore, BELLE, BABAR and LHCb founds hints for the violation of flavour universality in $B\to D^{(*)}\tau\nu$. In addition, there is the long-standing discrepancy in the anomalous magnetic moment of the muon. Interestingly, all these anomalies are related to muons and taus, while the corresponding electron channels seem to be SM like. This suggests that these deviations from the SM might be correlated and we briefly review some selected models providing simultaneous explanations.