Form Factors for Semi-Leptonic and Radiative Decays of Heavy Mesons to Light Mesons

B. Stech

Published 1995-12-24, updated 1996-01-19Version 2

To know and understand form factors of hadronic currents is of decisive importance for analysing exclusive weak decays. The ratios of different form factors of a given process depend on the relativistic spin structure of initial and final particles. It is shown --- assuming simple properties of the spectator particle --- that these ratios can entirely be expresssed in terms of particle and quark mass parameters. For quark masses large compared to the spectator mass the Isgur-Wise relations follow. The corresponding amplitudes for heavy-to-light transitions show a very similar structure. In particular, the $F_0$ and $A_1$ form factors behave again differently from the $F_1, A_2, V$ and $T_1$ form factors.