The σ and ρ in D and B decays

We study the D → σπ, D → ρπ, B− → σπ−, B− → ρ0π− and B̄ → ρ±π∓ decays in a valence quark triangle model, incorporating chiral symmetries. We find a good agreement with recent experimental data for D → σπ and for D → ρπ. We point out that a long-distance contribution due to the axial vector a1 meson pole, calculated by using chiral symmetry, can be relevant to explain D → ρπ and for lowering the ratio R = B ( B̄ → ρ±π∓ ) B (B− → ρ0π−) to be consistent with its phenomenological determination, within the large experimental uncertainity.