## Publications [#3910] of Thomas C. Mehen

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Papers Published
1. T. Mehen, Leptoproduction of $J/\Psi$, in Proceedings of the 29th International Conference on High Energy Physics (ICHEP 98), edited by A. Astbury, D. Axen, J. Robinson (1999), World Scientific .

Abstract:
I review the status of the extraction of NRQCD color-octet $J/\psi$ production matrix elements. Large theoretical uncertainties in current extractions from hadroproduction and photoproduction are emphasized. Leptoproduction of $J/\psi$ is calculated within the NRQCD factorization formalism. Color-octet contributions dominate the cross section, allowing for a reliable extraction of $<{\cal O}_8^{J/\psi}(^1S_0)>$ and $<{\cal O}_8^{J/\psi}(^3P_0)>$. A comparison with preliminary data from the H1 collaboration shows that leading order color-octet mechanisms agree with the measured total cross section for $Q^2 > 4m_c^2$, while the color-singlet model underpredicts the cross section by a factor of 5.