Sum Rule for Heavy Meson Decay Widths

Abstract

A sum rule relating the widths of the decays of mesons belonging to heavy quark multiplets, having the same parity and light quark spin j, into the low lying $0^-$ and $1^-$ multiplet is obtained. As this sum rule follows from properties of the axial charges, it is protected from heavy quark spin dependent $1/m_Q$ corrections. The sum rule works well for mesons containing a heavy charmed quark and, surprisingly, for resonances containing a strange quark.