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arXiv · hep-ph/9611218

Direct J/psi and psi' Polarization and Cross Sections at the Tevatron

M. Beneke·M. Kraemer
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Abstract

Transverse polarization of ${}^3 S_1$ charmonium states, produced directly in $p\bar{p}$ collisions at asymptotically large transverse momentum p_t, has emerged as the most prominent test of color octet contributions and spin symmetry in quarkonium production. We present predictions for the polar angle distribution at moderate values of p_t \sim 4 - 20 GeV, covered by the Tevatron Run I data. We update the fits of NRQCD matrix elements and discuss their theoretical uncertainties. With our best fit values, no transverse polarization is expected at p_t \sim 5 GeV, but the angular distribution is predicted to change dramatically as p_t increases to 20 GeV.

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M. Beneke, M. Kraemer. 1996-11-03. Direct J/psi and psi' Polarization and Cross Sections at the Tevatron. https://doi.org/10.1103/physrevd.55.5269

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