Note on recent measurements of the \psi(1S)\to\ga \eta_C(1S) and \psi(2S)\to\ga \eta_C(1S) branching ratios

Recently published measurements of the branching ratios {\cal B}(\psi(1S)\to\ga \eta_C(1S)) and {\cal B}(\psi(2S)\to\ga \eta_C(1S)) by the CLEO collaboration are examined in the context of a potential model that includes both relativistic and one-loop QCD corrections to the quark-antiquark interaction. The prediction for the width \Gamma(\psi(1S)\to\ga \eta_C(1S)) is in excellent agreement with the new data but the prediction for \Gamma(\psi(2S)\to\ga \eta_C(1S)) is too small. In an effort to understand this discrepancy, we derive an upper bound on \Gamma(\psi(2S)\to\ga \eta_C(1S)) and point out its experimental value saturates this bound.Comment: Corrected typos, addeded referenc

Recent developments in the modeling of heavy quarkonia

We examine the spectra and radiative decays of the cc-bar and bb-bar systems using a model which incorporates the complete one-loop spin-dependent perturbative QCD short distance potential, a linear confining term including (spin-dependent) relativistic corrections to order v^2/c^2, and a fully relativistic treatment of the kinetic energy. We compare the predictions of this model to experiments, including states and decays recently measured at Belle, BaBar, CLEO and CDF.Comment: 3 pages, contribution to PANIC05, Santa Fe, NM October 200