  New interactions with Lorentz scalar structure, arising from physics beyond
the standard model of electroweak interactions, will induce effective
pseudoscalar interactions after renormalization by weak interaction loop
corrections. Such induced pseudoscalar interactions are strongly constrained by
data on $\pi^\pm \to l^\pm \nu_l$ decay. These limits on induced pseudoscalar
interactions imply limits on the underlying fundamental scalar interactions
that in many cases are substantially stronger than limits on scalar
interactions from direct Beta-decay searches.
