Correlators of vector, tensor, and scalar composite vertices of order $O({\alpha }_s^2{\beta }_0)$

Abstract

We present analytical results for massless correlators of two vector, tensor, and scalar composite vertices with the Bjorken fractions $x$ and $y$ of order ${\alpha }_s^2{\beta }_0$ of QCD. The structure of these correlators ${\Pi }^{\text{V,T,S}}(x,y;p^2)$ and properties of its main elements are discussed in detail. Special attention is paid to verifying the results and comparing them with known particular cases. We apply the correlators to evaluate radiative corrections to the distribution amplitudes of light mesons within the QCD sum rules.

Comments: 25 pages, 4 figures; v4 corrects Eqs. (3.3d), (4.4d), (4.7), (B.14), and (D.3)