Threshold effect and π^\pm ψ(2S) peak

Abstract

A resonance-like structure in the $π^\pm ψ(2S)$ mass spectrum arising in $B \to K π^\pm ψ(2S)$ has recently been reported. It is noted that the mass of this structure, $4433 \pm 4 \pm 1$ MeV, is not far from the threshold for production of $D^* \bar{D}_1(2420)$. A proposed mechanism for production of this state is suggested, and tests are suggested.

4 pages, 1 figure. To be submitted to Phys. Rev. D (Brief Reports). Additional text, acknowledgment, references; note added on other work