Explaining the Flavor Anomalies with a Vector Leptoquark

Several experiments revealed intriguing hints for lepton flavor universality(LFU) violating new physics (NP) in semi-leptonic B meson decays, mainly in $b \rightarrow c\tau \nu$ and $b \rightarrow sl^+ l^-$ transitions at the 3−5 σ level. Leptoquarks (LQ) are primecandidates to address these anomalies as they contribute to semi-leptonic decaysalready at tree level while effects in other flavor observables, agreeing withthe standard model (SM), are loop suppressed. In these proceedings we review thevector leptoquark SU(2)L singlet, contained in the famous Pati-Salam model,which is able to address both $b \rightarrow c\tau \nu$ and $b \rightarrow s\mu^+ \mu^-$ data simultaneously. Dueto the large couplings to tau leptons needed to account for the $b \rightarrow c\tau \nu$ data,sizable loop effects arise which we include in our phenomenological analysis.Updating our result of Ref.$^1$ with the recent measurements of LHCb$^2$ and BELLE$^{3, 4}$ we find an even better fit to data than before.