P-wave radial mixing in mesons

Mixings between P-wave mesons and their radial excitations are shown to have a significant effect on standard evaluations of E1 radiative decays. The mixings, which are naturally induced by the one-gluon-exchange Fermi-Breit hamiltonian, also improve the predicted P-wave charmonium masses. Width calculations are performed for charmonium states and the usual prediction of $\text{Г(ψ′→}{}^3\text{P}{}_{\mathrm{0\gamma }}\text{)=40–50 KeV}$, for example, is reduced by a factor of two. Agreement with experiment is considerably improved.