Leptoquark flavor patterns & B decay anomalies

Flavor symmetries that explain masses and mixings of the standard model fermions dictate flavor patterns for the couplings of scalar and vector leptoquarks to the standard model fermions. a generic feature is that couplings to su(2)-doublet leptons are suppressed at least by one spurion of the discrete non-abelian symmetry breaking, responsible for neutrino mixing, while couplings to charged lepton singlets can be order one. we obtain testable patterns including those that predominantly couple to a single lepton flavor, or two, or in a skewed way. they induce lepton non-universality, which we contrast to current anomalies in b-decays. we find maximal effects in r d and $$ {r_d}_{{}^{ast }} $$ at the level of ∼10 percent and few percent, respectively, while leptoquark effects in $$ {r_k}_{{}^{left(ast right)}} $$ can reach order few×10 percent. predictions for charm and kaon decays and μ − e conversion are worked out.