Electromagnetic Simulation ofTViolation in Beta Decay

$\beta$-decay correlation terms of the form $\mathrm{J}·{\mathrm{p}}_e\times {\mathrm{p}}_{\nu }$ can arise, insofar as time-reversal invariance is valid, only from the influence of final-state electromagnetic interactions. For allowed transitions governed by $V$, $A$ couplings, the effects are recoil-dependent. They are computed here, to lowest relevant recoil and electro-magnetic orders, for the special class of spin-½ mirror transitions, of which the decay process ${\mathrm{Ne}}^{19}\to {\mathrm{F}}^{19}+e^{+}+\nu$ is an example. On the conserved-vector-current hypothesis, the correlation effect in question is seen to be dominated by the phenomenon of weak magnetism.