Charged- and neutral-current interference inνe−escattering

Abstract

In the scattering of electronic neutrinos ${\nu }_e$ by electrons, charged- and neutral-current weak interactions can interfere with each other. According to all the popular gauge models that are consistent with neutralcurrent data, including the measurements of polarized-electron-deuteron scattering, this interference should be negative. The conditions under which a beam-dump experiment can be used to study charged- and neutralcurrent interference are studied in detail. It appears that if the interference is assumed to be present in the first place, then a 25% measurement of the integrated cross section will allow one to determine its sign. Greater accuracy is required to show that the interference actually does occur in ${\nu }_e-e$ scattering. Tests for the presence of the helicity-flipping covariants $S$, $P$, $T$ are also discussed.