${\eta }^{(\prime )}$-meson twist-2 distribution amplitude within QCD sum rule approach and its application to the semi-leptonic decay $D_s^{+}\to {\eta }^{(\prime )}{\ell }^{+}{\nu }_{\ell }$

Dan-Dan Hu, Hai-Bing Fu, Tao Zhong +3

In this paper, we make a detailed discussion on the $\eta$ and ${\eta }^{\prime }$-meson leading-twist light-cone distribution amplitude ${\varphi }_{2;{\eta }^{(\prime )}}(u,\mu )$ by using QCD sum rules approach und…