  It has been suggested in Ref. [A. E. Bondar and V. L. Chernyak, Phys. Lett. B
612, 215 (2005)] that the disagreement between theoretical calculations and
experimental observations for the rate for the process e+ e- -> J/psi + eta_c
at the B factories might be resolved by using the light-cone method to take
into account the relative momentum of the heavy-quark and antiquark in the
quarkonia. The light-cone result for the production cross section in Ref. [A.
E. Bondar and V. L. Chernyak, Phys. Lett. B 612, 215 (2005)] is almost an order
of magnitude larger than existing NRQCD factorization results. We investigate
this apparent theoretical discrepancy. We compute light-cone distribution
functions by making use of quarkonium wave functions from the Cornell potential
model. Our light-cone distribution functions are similar in shape to those of
Ref. [A. E. Bondar and V. L. Chernyak, Phys. Lett. B 612, 215 (2005)] and yield
a similar cross section. However, when we subtract parts of the light-cone
distribution functions that correspond to corrections of relative-order alpha_s
in the NRQCD approach, we find that the cross section decreases by about a
factor of three. When we set certain renormalization factors Z_i in the
light-cone calculation equal to unity, we find a further reduction in the cross
section of about a factor of two. The resulting light-cone cross section is
similar in magnitude to the NRQCD factorization cross sections and shows only a
modest enhancement over the light-cone cross section in which the relative
momentum of the heavy-quark and antiquark is neglected.
