3S1-3D1 mixing and E1 radiative transitions in charmonium

The radiative tansitions psi'->γ+chisub(J) and chisub(J)->γ+psi are studied in the quark model with the psi and psi' interpreted conventionally as 3S1 canti c states and the chisub(J) as 3Psub(J) canti c states. In particular, the effect of 3S1-3D1 mixing on the decay widths is calculated. The photon angular distributions in these decays are also studied and are found to be a more sensitive test of 3D1 admixture in the psi states. The 3D1 content of the psi is found to be large but the estimate is very sensitive to the photon angular distributions. More precise measurements could help to explain the large psi'' leptonic width. (orig.)