“…At NLO, the direct-and resolved-photon contributions both strongly depend on the factorization scheme and scale, and must be combined in order to give a well-defined physical observable. From previous experience in connection with inclusive pion, kaon [15], and D * ± [16,17] photoproduction at HERA, one may infer that, in the case of J/ψ photoproduction via fragmentation, the resolved-photon contribution, which was disregarded in Ref. [14], is likely to be much more important than the direct one.…”