Charmonium Production via Fragmentation at Higher Orders in alpha_s
摘要
Quarkonium production at a given large p_T is dominated by parton fragmentation: a parton which is produced with transverse momentum p_T/z fragments into a quarkonium state which carries a fraction z of the parton momentum. Since parton production cross sections fall steeply with p_T, high z fragmentation is favored. However, quantum number constraints may require the emission of gluons in the fragmentation process, and this softens the z dependence of the fragmentation function. We discuss the possibility that higher- order processes may enhance the large z part of fragmentation functions and thus contribute significantly to the quarkonium cross section. An explicit calculation of light quark fragmentation into eta_c shows that the higher-order process q -> q eta_c in fact dominates the lowest-order process q -> qg eta_c.
引用
@article{arxiv.hep-ph/9601333,
title = {Charmonium Production via Fragmentation at Higher Orders in alpha_s},
author = {P. Ernstrom and P. Hoyer and M. Vanttinen},
journal= {arXiv preprint arXiv:hep-ph/9601333},
year = {2007}
}
备注
14 pages, LaTeX, 6 Postscript figures, uses epsf.sty