Relativistic correction to gluon fragmentation function into pseudoscalar quarkonium

Abstract

Inspired by the recent measurements of the ${\eta }_c$ meson production at LHC, we investigate the relativistic correction effect for the fragmentation function of the gluon into ${\eta }_c$, which constitutes the crucial nonperturbative elements to understand ${\eta }_c$ production at high $p_T$. Employing three distinct methods, we calculate the leading relativistic correction to the $g\to {\eta }_c$ fragmentation function in the NRQCD factorization framework, as well as verify the existing NLO result for the $c\to {\eta }_c$ fragmentation function. We also study the evolution behavior of these fragmentation functions with the aid of DGLAP equation.

Comments: 15 pages, 4 figures, 1 table, submitted to Chinese Physics C