Improved limits on scalar weak couplings

Abstract

I point out that \ensuremath{\beta}-delayed proton spectroscopy is a powerful probe of possible scalar contributions to nuclear \ensuremath{\beta} decay, and use Schardt and Riisager's data on the shape of the beta-delayed proton peaks from the superallowed decays of $^{32}\mathrm{Ar}$ and $^{33}\mathrm{Ar}$ to set improved upper limits on such couplings. Implications of these limits for leptoquark masses are mentioned.