  Motivated by an apparent paradox in [X L. Qi, E.Witten, S-C. Zhang, Phys.
Rev. B 87 134519 (2013)] we use the method of gauged Wess-Zumino-Witten
functionals to construct an effective action for a Weyl fermion whose Majorana
mass arises from coupling to a charged condensate. We obtain expressions for
the current induced by an external gauge field and observe that the topological
part of the current is only one-third of that that might have been expected
from the gauge anomaly. The anomaly is not changed by the induced mass gap
however. The topological current is supplemented by a conventional supercurrent
that supplies the remaining two-thirds of the anomaly once the equation of
motion for the Goldstone mode is satisfied. We apply our formula for the
current to resolve the apparent paradox, and also to the chiral magnetic effect
(CME) where it predicts a reduction of the CME current to one third of its
value for a free Weyl gas in thermal equilibrium. We attribute this reduction
to a partial cancelation of the CME by a chiral vortical effect (CVE) current
arising from the persistent rotation of the fluid induced by the external
magnetic field.
