Zeros inγ+e→W+ν

We point out a misprint in the differential cross section for $\gamma e\to W\nu$ reported recently by Ginzburg, Kotkin, Panfil, and Serbo. The corrected expression has a zero in accordance with the general formula derived earlier by Mikaelian. We plot the angular distributions for different values of $\kappa$, the anomalousmagnetic-moment parameter of the $W$. We suggest that the reaction $\gamma e\to W\nu$ is an attractive way to measure $\kappa$ because the distributions are sensitive to it and the zero exists only if $\kappa =+1\mathrm{}$ as in the standard electroweak theory.