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Polarization of Charmonium in πN Collisions

Wai-Keung Tang
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Abstract

Measurements of the polarization of $\jp$ produced in pion-nucleus collisions are in disagreement with leading twist QCD prediction where $\jp$ is observed to have negligible polarization whereas theory predicts substantial polarization. We argue that this discrepancy cannot be due to poorly known structure functions nor the relative production rates of $\jp$ and $χ_J$. The disagreement between theory and experiment suggests important higher twist corrections, as has earlier been surmised from the anomalous non-factorized nuclear $A$-dependence of the $\jp$ cross section.

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Wai-Keung Tang. 1994-10-06. Polarization of Charmonium in πN Collisions. https://arxiv.org/abs/hep-ph/9410238

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