Interplay of Confinement and Decay in the Spectrum of Charmonium

Abstract

The spectrum of charmonium in the presence of a charmed-meson continuum is investigated. Radiative rates are in considerably better agreement with data than for the naive model, the largest discrepancy being a factor 2-3 for ${\psi }^{\prime }\to \gamma +{}_{}{}^3{}_{}{}^{}P_0^{}{}_{}{}^{}$. The model accounts for the peak at ∼ 4.2 GeV in $\sigma (e\overline{e}\to \mathrm{had})$, and predicts a further peak at ∼ 3.75 GeV due to $1{}_{}{}^3{}_{}{}^{}D_1^{}{}_{}{}^{}$. The latter would be the most favorable location for a charm search in $e\overline{e}$ collisions.