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We investigate the origin of the double logarithms of Q^2/m_c^2 that appearin the calculation of the cross section for e+e- -> J/psi + eta_c atnext-to-leading order in alpha_s. We find that, diagram-by-diagram, the doublelogarithms are accounted for by Sudakov double logarithms and endpoint doublelogarithms. The Sudakov double logarithms cancel in the sum over all diagrams,but the endpoint double logarithms do not. We reinterpret the endpoint doublelogarithms in terms of a leading region of loop integration in which aspectator fermion line becomes soft. This reinterpretation may simplify theprocess of establishing an all-orders factorization theorem for thishelicity-flip process, which, in turn, might allow one to resum logarithms ofQ^2/m_c^2 to all orders in alpha_s.

Endpoint Logarithms in e+e- -> J/psi + eta_c