  The chiral anomaly in Weyl semimetals states that the left- and right-handed
Weyl fermions, constituting the low energy description, are not individually
conserved, resulting, for example, in a negative magnetoresistance in such
materials. Recent experiments see strong indications of such an anomalous
resistance response; however, with a response that at strong fields is more
sharply peaked for parallel magnetic and electric fields than expected from
simple theoretical considerations. Here, we uncover a mechanism, arising from
the interplay between the angle-dependent Landau level structure and long-range
scalar disorder, that has the same phenomenology. In particular, we ana-
lytically show, and numerically confirm, that the internode scattering time
decreases exponentially with the angle between the magnetic field and the Weyl
node separation in the large field limit, while it is insensitive to this angle
at weak magnetic fields. Since, in the simplest approximation, the internode
scattering time is proportional to the anomaly-related conductivity, this
feature may be related to the experimental observations of a sharply peaked
magnetoresistance.
