Threshold resummation beyond leading eikonal level
Abstract
The modified evolution equation for parton distributions of Dokshitzer, Marchesini and Salam is extended to non-singlet Deep Inelastic Scattering coefficient functions and the physical evolution kernels which govern their scaling violation. Considering the x->1 limit, it is found that the leading next-to-eikonal logarithmic contributions to the momentum space physical kernels at any loop order can be expressed in term of the one loop cusp anomalous dimension, a result which can presumably be extended to all orders in (1-x). Similar results hold for fragmentation functions in semi-inclusive e^{+}e^{-} annihilation. The method does not work for subleading next-to-eikonal logarithms, but, in the special case of the F_1 and F_T structure and fragmentation functions, there are hints of the possible existence of an underlying Gribov-Lipatov like relation.
Keywords
Cite
@article{arxiv.1005.5684,
title = {Threshold resummation beyond leading eikonal level},
author = {Georges Grunberg},
journal= {arXiv preprint arXiv:1005.5684},
year = {2010}
}
Comments
6 pages; to appear in the Proceedings of DIS 2010, XVIII International Workshop on Deep-Inelastic Scattering and Related Subjects, April 2010, Firenze, Italy