EXCITED CHARM MESONS IN SEMILEPTONIC BBAR DECAY AND THEIR CONTRIBUTIONS TO A BJORKEN SUM-RULE

It has recently been shown that hadrons containing a single heavy quark exhibit a new flavor-spin symmetry of QCD. We exploit this symmetry to obtain model-independent predictions for the 14 form factors in weak decays from the ground-state pseudoscalar meson P(Q)i of a heavy quark Q(i) to the low-lying positive-parity excited states of a heavy quark Q(j) in terms of two universal functions of momentum transfer. These predictions are of interest in the study of BBAR --> D2* (2460), D1(2420), D1(approximately 2360), and D0* (approximately 2360) semileptonic decays. We also discuss the connection between these results and the slope of the function xi (which determines the BBAR --> D and BBAR --> D* transition form factors) given by a heavy-quark sum rule suggested by Bjorken.