Exclusive decays of heavy and light mesons.

Abstract

In the exclusive decay of the {ital B} meson into a {ital K}{sup *} and a photon, the large recoil momentum creates a difficulty in making a connection between the quark level calculations and the meson states. In the quark model, depending on how the recoil momentum is handled, this can lead to differences of a factor of about 5 in the branching ratio. In order to explore this problem, we look at some other meson processes where there exist some experimental data. For the {pi} form factor we show that, by imposing current conservation together with relativistic meson and spinor normalizations within the quark model, it is possible to remove a parameter {kappa} which had previously been introduced to obtain agreement with the form-factor data. The data on the decay {omega}{r arrow}{pi}{sup 0}{mu}{sup +}{mu}{sup {minus}} and {omega}{r arrow}{pi}{sup 0}{gamma} also show the importance of retaining relativistic meson and spinor normalizations; however, we do not resolve the recoil problem. For the exclusive decays {ital B}{r arrow}{ital K}{sup *}{gamma} and {ital B}{r arrow}{ital K}{sup *}{ital e+}{ital e{minus}} we show the extent to which the heavy-quark symmetries determine these decays, even in regions of large recoil.