SU(3) CORRECTIONS TO B-]DL(V)OVER-BAR FORM-FACTORS AT O(1/M)

We compute the O(1/M, m(s)) heavy quark and SU(3) corrections to (B) over bar(s) --> D(s)ev form factors. In the limit of vanishing light quark mass, (B) over bar(s) --> D(s)ev form factors are given in terms of the the (B) over bar --> Dev form factors, the leading order chiral parameter g, and two O(1/M) chiral parameters g(1) and g(2). All the chiral parameters can be extracted, in principle, from other heavy meson decays. Analytic counterterms proportional to the strange quark mass are presented for completeness, but no predictive power remains when they are included. Anomalously large loop corrections warn of poor convergence of the heavy quark chiral symmetry expansion for these processes. This suggests that naive extrapolations of (B) over bar --> D form factors relying on heavy quark and chiral symmetries, as often used in monte carlo simulations of lattice QCD, may incur large errors.