HEAVY-QUARK AND CHIRAL-SYMMETRY PREDICTIONS FOR SEMILEPTONIC DECAYS (B)OVER-BAR-]D(D-ASTERISK)PI-L(NU)

We study in detail the prediction for the semileptonic decays BBAR --> D(D)pilnuBAR by heavy quark and chiral symmetry. The branching ratio for BBAR --> DpilnuBAR is quite significant, as big as (0.5-1)%. The branching ratio for BBAR --> DpilnuBAR is only of the order of 10(-4) -10(-5). Numerical results for various single-particle spectra and the ir dependence on the pion momentum cutoff schemes are presented in a s eries of figures, as are the model-independent ratios for differential rates of D and D. We also study the parity-violation effects on the decay rates for different polarization states of the D.