2017/06/03 by Crivellin, Andreas
#FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph)
paper · doi:10.48550/arxiv.1706.00929
LHCb found hints for physics beyond the Standard Model (SM) in B→ K^*μ+μ-, R(K) and Bs→ϕμ+μ-. These intriguing hints for NP have recently been confirmed by the LHCb measurement of R(K^*) giving a combined significance for NP above the 5 σ level. In addition, the BABAR, BELLE and LHCb results for B→ D(*)τν also point towards lepton flavour universality (LFU) violating new physics (NP). Furthermore, there is the long-standing discrepancy between the measurement and the theory prediction of the anomalous magnetic moment of the muon (aμ) at the 3 σ level. Concerning NP effects, b→ sμ+μ- data can be naturally explained with a new neutral gauge bosons, i.e. a Z^′ but also with heavy new scalars and fermions contributing via box diagrams. Another promising solution to b→ sμ+μ-, which can also explain B→ D(*)τν, are leptoquarks. Interestingly, leptoquarks provide also a viable explanation of aμ which can be tested via correlated effects in Z→μ+μ- at future colliders. Considering leptoquark models, we show that an explanation of B→ D(*)τν predicts an enhancement of b→ sτ+τ- processes by around three orders of magnitude compared to the SM. In case of a simultaneous explanation of B→ D(*)τν and b→ sμ+μ- data, sizable effects in b→ sτμ processes are predicted.