Published: 2009
Total Pages: 7
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We update the study of the QCD corrections to direct J/? and? hadroproduction in association with a photon in the QCD-based approach of the Colour-Singlet (CS) Model. After comparison with the recent full next-to-leading-order (NLO) computation for this process, we provide an independent confirmation to the inclusive case that NLO QCD corrections to quarkonium-production processes whose LO exhibits a non-leading P{sub T} behavior can be reliably computed at mid and large P{sub T} by considering only the real emission contributions accompanied with a kinematical cut. In turn, we evaluate the leading part of the?{sub S}4? contributions, namely those coming from (J/?,?) +? associated with two light partons. We find that they are dominant at mid and large P{sub T}. This confirms our expectations from the leading P{sub T} scaling of the new topologies appearing at NNLO. We obtain that the yield from the CS becomes one order of magnitude larger than the upper value of the potential Colour-Octet yield. The polarization of the 3S1 quarkonia produced in association with a photon is confirmed to be longitudinal at mid and large P{sub T}.