On three-body $B^0\to D^{\ast -}{D}^{(\ast )0}{K}^{+}$ decays and couplings of heavy mesons to light pseudoscalar mesons

We analyze the decay modes $B^0\to D^{\ast -}{D}^0{K}^{+}$ and $B^0 \to D^{*-} D^{*0} K^+$ and, using the available experimental data, we find bounds for the constants g and h describing the strong coupling of heavy mesons to light pseudoscalar mesons. Both the decay channels are dominated by broad L=1 charm resonances; the dominance is effective also in $B^0\to D^{-}{D}^0{K}^{+}$ and $B^0 \to D^{-} D^{*0} K^+$.