AbstractA symmetry-preserving regularisation of a vector $$\times $$
×
vector contact interaction (SCI) is used to deliver a unified treatment of semileptonic transitions involving $$\pi $$
π
, K, $$D_{(s)}$$
D
(
s
)
, $$B_{(s,c)}$$
B
(
s
,
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 $$B_{s,c}$$
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 $$B_{(s)}\rightarrow D_{(s)}$$
B
(
s
)
→
D
(
s
)
transitions yield a prediction for the Isgur–Wise function in fair agreement with contemporary data.
Pseudoscalar meson transition form factors
