Recent measurements by the Belle Collaboration of the exclusive production of two charmonia in e(+)e(-) annihilation differ substantially from theoretical predictions. We suggest that a significant ...part of the discrepancy can be explained by the process e(+)e(-)-->J/psi+J/psi. Because the J/psi+J/psi production process can proceed through fragmentation of two virtual photons into two cc pairs, its cross section may be larger than that for J/psi+eta(c) by about a factor of 3.7, in spite of a suppression factor alpha(2)/alpha(2)(s) that is associated with the QED and QCD coupling constants.
We calculate the decay rates of {ital B} mesons into {ital P}-wave charmonium states using new factorization formulas that are valid to leading order in the relative velocity of the charmed quark and ...antiquark and to all orders in the running coupling constant of QCD. We express the production rates for all four {ital P} states in terms of two nonperturbative parameters: the derivative of the wave function at the origin and another parameter related to the probability for a charmed-quark--antiquark pair in the color-octet {ital S}-wave state to radiate a soft gluon and form a {ital P}-wave bound state. Using existing data on {ital B} meson decays into {chi}{sub {ital c}1} to estimate the color-octet parameter, we find that the color-octet mechanism may account for a significant fraction of the {chi}{sub {ital c}1} production rate and that {ital B} mesons should decay into {chi}{sub {ital c}2} at a similar rate.
Rigorous QCD predictions for the decay rates of the {ital P}-wave states of heavy quarkonia are presented. They are based on a new factorization theorem which is valid to leading order in the ...heavy-quark velocity and to all orders in the running coupling constant of QCD. The decay rates for all four {ital P} states into light-hadronic or electromagnetic final states are expressed in terms of two phenomenological parameters, whose coefficients are perturbatively calculable. Logarithms of the binding energy encountered in previous perturbative calculations of {ital P}-wave decays are factored into a phenomenological parameter that is related to the probability for the heavy--quark-antiquark pair to be in a color-octet {ital S}-wave state. Applying these predictions to charmonium, we use measured decay rates for the {chi}{sub {ital c}1} and {chi}{sub {ital c}2} to predict the decay rates of the {chi}{sub {ital c}0} and {ital h}{sub {ital c}}.
We find that the definition of the heavy-quark fragmentation function given by Jaffe and Randall differs by a factor of the longitudinal-momentum fraction z from the standard Collins-Soper ...definition. Once this factor is taken into account, the explicit calculation of Braaten is found to be in agreement with the general analysis of Jaffe and Randall. We also examine the model of Peterson for heavy-quark fragmentation and find that the quoted values of the width and of the value of z at the maximum are in error. The corrected values are in agreement with the analysis of Jaffe and Randall.
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