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arXiv · hep-ph/9908334

NLO corrections and contribution of a tensor gluon operator to the process $γ^*γ\to ππ$

N. Kivel·L. Mankiewicz·M. V. Polyakov
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Abstract

We have calculated the NLO corrections for the leading twist amplitude of the reaction $γ^*γ\toππ$ at large virtuality of the photon and at $W^2\ll Q^2$. With a simple model for the two-pion quark and gluon distribution amplitudes we have estimated that the NLO effects may reduce the leading-order amplitude by as much as 30%. We have found that besides the usual twist-2 quark and gluon operators the NLO amplitude receives contribution from a distribution associated with twist-2 tensor gluon operator. The new gluon distribution can be investigated by studying the azimuthal asymmetry of the cross section for $e+γ\to e'+ππ$.

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N. Kivel, L. Mankiewicz, M. V. Polyakov. 1999-09-28. NLO corrections and contribution of a tensor gluon operator to the process $γ^*γ\to ππ$. https://doi.org/10.1016/s0370-2693(99)01148-x

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