Relativistic corrections to $\psi (nS)\to \rho \pi$ exclusive decays and their role in the understanding of the $\rho \pi$-puzzle

Nikolay Kivel

We study relativistic corrections to exclusive $S$-wave charmonium decays into $\rho \pi$ and $\gamma \pi$ final states. The contribution of relative order $v^2$ and the set of associated higher…