The ground-state positive-parity charmonia \ (₂₀ (1P) \), \ (₂₁ (1P) \), \ (hc (1P) \), and \ (₂₂ (1P) \) are generally well described in static (“quenched”) quark models, in which dynamical effects of actual or virtual strong decay are neglected. In contrast, the five PDG candidates for \ (P\) -wave charmonia in the energy region of 3. 85–3. 95 GeV, probably including the first radial excitations of the above ones, display a totally different and quite disparate mass pattern. Moreover, two scalar states are listed, viz. \ (₂₀ (3860) \) and \ (₂₀ (3915) \), the former one apparently being very broad. Preliminary results will be presented here for the first radial excitations of the lowest \ (P\) -wave \ (c c\) states, obtained with the Resonance-Spectrum Expansion while including in the calculation all OZI-allowed decay channels of the most relevant charm-meson pairs. Employing a generalised scheme of computing coupling constants for decays based on the \ (^3\!P₀\) model ensures that no distortion of the spectra will occur due to the different classes of allowed decay channels for the various positive-parity charmonia. Abstract Published by the Jagiellonian University 2026 authors
George Rupp (Fri,) studied this question.