hc production at hadron colliders

In this paper, we present the study of the hadroproduction rate of h(c) at next-to-leading order in a(s) under the nonrelativisitic QCD (NRQCD) factorization framework, using color-octet long-distance matrix elements obtained from a global fit of experimental measurements on chi(c) yield and the ratio d sigma(chi(c2))/d sigma(chi(c1)) from the CDF, LHCb, CMS, and ATLAS Collaborations. This paper considers the problem of NRQCD scale dependence for the first time, and finds that, for some experimental conditions, the choice of this scale can significantly affect the final results, which indicates that, for these conditions, theoretical evaluation up to next-to-leading order cannot provide sufficiently precise predictions. We also present a brief analysis on the NRQCD scale dependence problem, and provide a criterion to determine in which case next-to-leading order prediction would be ruined by the scale dependence.