Leading twist distribution amplitudes ofP-wave nonrelativistic mesons

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 $P$-wave charmonia mesons are considered. Within QCD sum rules the model for the universal function of $P$-wave charmonia mesons is built. In addition, relations are found 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 $\ensuremath{\sim}30%$.