On threshold resummation of the longitudinal structure function

Georges Grunberg

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arXiv · 0910.3894

On threshold resummation of the longitudinal structure function

Georges Grunberg

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Abstract

The validity of a previously proposed momentum space ansatz for threshold resummation of the non-singlet longitudinal structure function F_L is checked against existing finite order three-loop results. It is found that the ansatz, which is an assumption for the large-x behavior of the physical evolution kernel, does not work beyond the leading logarithmic contributions to the kernel even at {\cal O}(1/(1-x)) order (except at large-β_0), which is consistent with a recent observation of Moch and Vogt. Corrections down by one power of 1-x are also studied. At {\cal O}((1-x)^0) order, the corresponding ansatz fails already at the leading logarithmic level, where the situation appears similar to that encountered in the case of the F_i (i=1,2,3) structure functions. At the next-to-leading logarithmic level, the same term (with opposite sign) responsible for the failure of the ansatz at {\cal O}(1/(1-x)) order is found to occur.

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Georges Grunberg. 2009-10-20. On threshold resummation of the longitudinal structure function. https://arxiv.org/abs/0910.3894

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