Neutrino electroweak radius

We study a combination of amplitudes for neutrino scattering that can isolate a (gauge-invariant) difference of chirality-preserving neutrino electroweak radii for ${\ensuremath{\nu}}_{\ensuremath{\mu}}$ and ${\ensuremath{\nu}}_{\ensuremath{\tau}}.$ This involves both photon and ${Z}_{\ensuremath{\mu}}$ exchange contributions. It is shown that the construction singles out the contributions of the hypercharge gauge field ${B}_{\ensuremath{\mu}}$ in the standard model. We comment on how gauge-dependent terms from the charge radii cancel with other terms in the relative electroweak radii.