Hadro-Production of Quarkonia in Fixed Target Experiments

Abstract

In this talk I review the recent progress made in the calculations of quarkonia production in fixed target experiments. NRQCD organizes the calculations in a systematic expansion in ${\alpha }_s$ and $v$, the relative velocity between the heavy quarks. Within this formalism there are octet contributions which are not included in the color singlet model. These contributions depend upon unknown matrix elementsof local operators which are fit to the data. Using these fits, there are several predictions which do indeed improve agreement with the data. However, the prediction for the polarization of the produced states as well as the ratio of the ${\chi }_1$ to ${\chi }_2$ cross sections differ substantially from the data for the case of pion beams. Possible large corrections from higher twist effects are discussed as is the issue of the the proper choice of masses.

10 pages, 2 figures included. To appear in the Proceedings of the University of Illinois, Chicago, Quarkonium Workshop, June 13-15, 1996

References in corpus (1)

• Quarkonium production and decays

Cited by in corpus (6)

• Measurement of $J/\psi$ polarization in $pp$ collisions at $\sqrt{s}=7$ TeV
• Event activity dependence of Y(nS) production in sqrt(s[NN]) = 5.02 TeV pPb and sqrt(s) = 2.76 TeV pp collisions
• NRQCD Factorization and Velocity-dependence of NNLO Poles in Heavy Quarkonium Production
• J/psi Production at LEP: Revisited and Resummed
• Fixed-target charmonium production and pion parton distributions
• Color Octet Contribution to J/psi Photoproduction Asymmetries