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On power corrections to the event shape distributions in QCD

G. P. Korchemsky·S. Tafat
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Abstract

We study power corrections to the differential thrust, heavy jet mass and C-parameter distributions in the two-jet kinematical region in e^+e^- annihilation. We argue that away from the end-point region, e>> Λ_{QCD}/Q, the leading 1/Q-power corrections are parameterized by a single nonperturbative scale while for e Λ_{QCD}/Q one encounters a novel regime in which power corrections of the form 1/(Qe)^n have to be taken into account for arbitrary n. These nonperturbative corrections can be resummed and factor out into a universal nonperturbative distribution, the shape function, and the differential event shape distributions are given by convolution of the shape function with perturbative cross-sections. Choosing a simple ansatz for the shape function we demonstrate a good agreement of the obtained QCD predictions for the distributions and their lowest moments with the existing data over a wide energy interval.

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G. P. Korchemsky, S. Tafat. 2000-07-02. On power corrections to the event shape distributions in QCD. https://doi.org/10.1088/1126-6708%2F2000%2F10%2F010

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