Heavy plus light pseudoscalar meson semileptonic transitions

A symmetry-preserving regularisation of a vector x vector contact interaction (SCI) is used to deliver a unified treatment of semileptonic transitions involving pi, K, D-(s), B-(s,B- (c)) initial states. The framework is characterised by algebraic simplicity, few parameters, and the ability to simultaneously treat systems from Nambu-Goldstone modes to heavy+heavy mesons. Although the SCI form factors are typically somewhat stiff, the results are comparable with experiment and rigorous theory results. Hence, predictions for the five unmeasured B(s,c )branching fractions should be a reasonable guide. The analysis provides insights into the effects of Higgs boson couplings via current-quark masses on the transition form factors; and results on B-(s) -> D-(s) transitions yield a prediction for the Isgur-Wise function in fair agreement with contemporary data.

Automated summary

This study uses a symmetry-preserving regularisation to provide a unified treatment of semileptonic transitions involving different initial states, with results indicating that predictions for the unmeasured B(s,c) branching fractions are reliable and offering insights into the effects of Higgs boson couplings on transition form factors.