Heavy Hadron Chiral Perturbation Theory

Abstract

The formalism and applications of chiral perturbation theory for hadrons containing a single heavy quark are discussed. We emphasize the utility of working directly with the velocity dependent ``super'' fields which appear in the chiral Lagrangian and whose interactions manifestly preserve heavy quark spin symmetry rather than their individual spin components. Chiral logarithm corrections to meson and baryon Isgur-Wise functions are found using these fields. We also identify a unique dimension-five operator which couples the axial vector Goldstone current to the heavy antitriplet baryon field $T_\Q$. We then compute the differential rate for the spin symmetry violating decay $T_b(v) \to T_c(v') \ell \bar{\v}_\ell π$. The ratio of this decay rate to that for the corresponding pure semileptonic transition can be studied away from the zero recoil point.