The Effective ${\eta }^{\prime }{g}^{\ast }{g}^{\ast }$ Vertex at Arbitrary Gluon Virtualities

Abstract

The effective ${\eta }^{\prime }{g}^{\ast }{g}^{\ast }$ vertex is studied in the standard (Brodsky-Lepage) and modified hard scattering approaches for arbitrary gluon virtualities in the time-like and space-like regions. The contribution of the gluons in the ${\eta }^{\prime }$-meson is taken into account, and the wave-function is constrained using data on the electromagnetic transition form factor of the ${\eta }^{\prime }$ meson. Our results have implications for the inclusive decay $B\to {\eta }^{\prime }X$ and exclusive decays, such as $B\to {\eta }^{\prime }(K,K^{\ast })$, and in hadronic production processes $N+N(\bar{N})\to {\eta }^{\prime }X$.

19 pages, 6 figures (requires amssymb, epsf); Invited Talk; Conference of the Nuclear Physics Department of the Russian Academy of Sciences: Fundamental Interactions of Elementary Particles, Moscow, November 27 -- December 1, 2000