  We present a simple yet effective theory that predicts the existence of
resonant radiation bands in the deep normal group velocity dispersion region of
a medium, even in absence of a zero-group velocity dispersion point. This
radiation is evident when the medium is pumped with high-energy ultrashort
pulses, and it is driven by the interplay between the Kerr and the shock terms
in the NLSE. Accurate experiments performed in bulk silica fully support the
theoretical phase-matching condition found by our theory.
