ON (P)OVER-BAR-P DECAY WIDTHS OF HEAVY QUARKONIUM STATES

We discuss the decay widths and branching ratios of charmonium and bottomonium levels into ppBAR final states. The values of these widths and corresponding branching ratios determine quarkonia production cross-sections as s-channel resonances in ppBAR annihilation. From the known values of charmonia decay widths into different channels and using non-relativistic formulas for S-, P- and D-state transitions into gluons we obtain the predictions for decay widths of 1P1, and 3D1 charmonium levels into the ppBAR final state. To estimate ppBAR decay widths for 3P0, 3D2, 3D3 and 1D2 charmonium levels we made some plausible assumptions on the dependence of the amplitude of the gluon transition into the pp state on angular momentum and parity. Then, using the energy behavior of the amplitude of ppBAR annihilation into gluons given by the non-perturbative quark-gluon model we come to estimates of ppBAR decay widths and branching ratios for the 2 1S0 level of charmonium and the S- and P-levels of bottomonium.