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Towards a solution of the charmonium production controversy: k_t-factorization versus color octet mechanism

Ph. Hagler·R. Kirschner·A. Schafer·L. Szymanowski·O. V. Teryaev
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Abstract

The cross section of χ_{cJ} hadroproduction is calculated in the k_t-factorization approach. We find a significant contribution of the χ_{c1} state due to non-applicability of the Landau-Yang theorem because of off-shell gluons. The results are in agreement with data and, in contrast to the collinear factorization, show a dominance of the color singlet part and a strong suppression of the color octet contribution. Our results could therefore lead to a solution of the longstanding controversy between the color singlet model and the color octet mechanism.

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Ph. Hagler, R. Kirschner, A. Schafer, L. Szymanowski, O. V. Teryaev. 2001-03-14. Towards a solution of the charmonium production controversy: k_t-factorization versus color octet mechanism. https://doi.org/10.1103/physrevlett.86.1446

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