Leading twist distribution amplitudes of P-wave nonrelativistic mesons

TL;DR

This paper investigates the leading twist distribution amplitudes of P-wave nonrelativistic mesons, expressing them through a universal function and analyzing relativistic corrections for P-wave charmonia using QCD sum rules.

Contribution

It introduces a universal function for P-wave meson distribution amplitudes and relates its moments to nonrelativistic QCD matrix elements, including relativistic correction estimates.

Findings

Distribution amplitudes expressed via a universal function

Relations established between moments and QCD matrix elements

Relativistic corrections estimated to be around 30%

Abstract

This paper is devoted to the study of the leading twist distribution amplitudes of P-wave nonrelativistic mesons. It is shown that at the leading order approximation in relative velocity of quark-antiquark pair inside the mesons these distribution amplitudes can be expressed through one universal function. As an example, the distribution amplitudes of the P-wave charmonia mesons are considered. Within QCD sum rules the model for the universal function of P-wave charmonia mesons is built. In addition, it is found the relations between the moments of the universal function and the nonrelativistic QCD matrix elements that control relativistic corrections to any amplitude involving P-wave charmonia. Our calculation shows that characteristic size of these corrections is of order of ~30 %.