  We study electrical transport at quantum critical points (QCPs) associated
with loop current ordering in a metal, focusing specifically on models of the
"Hertz-Millis" type. At the infrared (IR) fixed point and in the absence of
disorder, the simplest such models have infinite DC conductivity and zero
incoherent conductivity at nonzero frequencies. However, we find that a
particular deformation, involving $N$ species of bosons and fermions with
random couplings in flavor space, admits a finite incoherent,
frequency-dependent conductivity at the IR fixed point,
$\sigma(\omega>0)\sim\omega^{-2/z}$, where $z$ is the boson dynamical exponent.
Leveraging the non-perturbative structure of quantum anomalies, we develop a
powerful calculational method for transport. The resulting "anomaly-assisted
large $N$ expansion" allows us to extract the conductivity systematically.
Although our results imply that such random-flavor models are problematic as a
description of the physical $N = 1$ system, they serve to illustrate some
general conditions for quantum critical transport as well as the
anomaly-assisted calculational methods. In addition, we revisit an old result
that irrelevant operators generate a frequency-dependent conductivity,
$\sigma(\omega>0) \sim \omega^{-2(z-2)/z}$, in problems of this kind. We show
explicitly, within the scope of the original calculation, that this result does
not hold for any order parameter.
