Flavor phenomenology of the leptoquark singlet-triplet model

Abstract In recent years, experiments revealed intriguing hints for new physics (NP) in semi-leptonic B decays. Both in charged current processes, involving b → cτν transitions, and in the neutral currents b → sℓ + ℓ − , a preference for NP compared to the standard model (SM) of more that 3σ and 5σ was found, respectively. In addition, there is the long-standing tension between the theory prediction and the measurement of the anomalous magnetic moment (AMM) of the muon (a μ ) of more than 3σ. Since all these observables are related to the violation of lepton flavor universality (LFU), a common NP explanation seems not only plausible but is even desirable. In this context, leptoquarks (LQs) are especially promising since they give tree-level effects in semi-leptonic B decays, but only loop-suppressed effects in other flavor observables that agree well with their SM predictions. Furthermore, LQs can lead to a m t /m μ enhanced effect in a μ , allowing for an explanation even with (multi) TeV particles. However, a single scalar LQ representation cannot provide a common solution to all three anomalies. In this article we therefore consider a model in which we combine two scalar LQs: the SU(2) L singlet and the SU(2) L triplet. Within this model we compute all relevant 1-loop effects and perform a comprehensive phenomenological analysis, pointing out various interesting correlations among the observables. Furthermore, we identify benchmark points which are in fact able to explain all three anomalies (b → cτν, b → sℓ + ℓ − and a μ ), without violating bounds from other observables, and study their predictions for future measurements.