SEMILEPTONIC DECAYS OF HEAVY MESONS TO LIGHT PSEUDOSCALAR MESONS IN THE BS FORMALISM

The decay processes from heavy to light pseudoscalar mesons such as pi , K, eta, eta' are studied in a relativistic constituent quark model b ased on the BS formalism. It is emphasized that the negative energy pr ojector operators's contributions in the BS wavefunctions for light ps eudoscalar mesons have to be considered. By taking into account these contributions, the previously encountered difficulties in calculating the decay constants and form factors are found to le removed. All the form factors for transitions such as D --> pi, D --> K, D-s --> K, D-s --> eta, D-s --> eta', B --> pi, B-s --> K are estimated and the bran ching ratios for these semileptonic decays are calculated. The results of our calculations are consistent with experimental values.