Chiral corrections to the fV⊥/fV ratio for vector mesons

In this paper we compute the leading chiral corrections to the ratio between the tensor and the vector decay couplings for the lowest lying vector meson multiplet (ρ, K∗, ϕ). We show that the leading chiral logarithms arise from tadpole contributions and are therefore entirely fixed by chiral symmetry, while the next to leading corrections are purely analytic. Interestingly, the flavour structure of the chiral logarithms implies that only the ρ meson is sensitive to pion logarithms at leading order: the K∗ channel is free from pion logarithms and only tiny O(mπ2NC−2) contributions affect the ϕ channel. By examining SU(2)L×SU(2)R×U(1)S theories we show that this result can be easily understood and that it holds to all orders in the ms expansion. Recent lattice data seem to comply with our results.