Inverse moment of the $B_s$-meson distribution amplitude from QCD sum rule

Abstract

We derive a QCD sum rule for the inverse moment of the $B_s$-meson light-cone distribution amplitude in HQET. Within this method, the $SU(3{)}_{fl}$ symmetry violation is traced to the strange quark mass and to the difference between strange and nonstrange quark condensate densities. We predict the ratio of inverse moments ${\lambda }_{B_s}/{\lambda }_B=1.19\pm 0.14$ which can be used in various applications of these distribution amplitudes to the analyses of $B_s$-meson decays, provided an accurate value of ${\lambda }_B$ is available from other sources, such as the $B\to \ell {\nu }_{\ell }\gamma$ decay.

Comments: Matches with the published version