  Studies of non-Fermi liquid properties in heavy fermions have led to the
current interest in the Bose-Fermi Kondo model. Here we use a dynamical large-N
approach to analyze an SU(N)xSU($\kappa N$) generalization of the model. We
establish the existence in this limit of an unstable fixed point when the
bosonic bath has a sub-ohmic spectrum ($|\omega|^{1-\epsilon} \sgn \omega$,
with $0<\epsilon<1$). At the quantum critical point, the Kondo scale vanishes
and the local spin susceptibility (which is finite on the Kondo side for \kappa
<1) diverges. We also find an \omega/T scaling for an extended range (15
decades) of \omega/T. This scaling violates (for $\epsilon \ge 1/2$) the
expectation of a naive mapping to certain classical models in an extra
dimension; it reflects the inherent quantum nature of the critical point.
