Neutrino production, oscillation and detection in the presence of general four-fermion interactions

Abstract

In this note we investigate the impact of new physics in the form of general four-fermion interactions on neutrino oscillation signals. We develop a field theoretic description of the overall oscillation process which includes the non-standard interactions during the neutrino production, propagation and detection stages. Insights gained during the development of this formalism regarding the possibility of new interactions mimicking neutrino mass differences are expounded. The impact of possible new physics is assessed by studying the $ν_μ\toν_τ$ oscillation channel in vacuum and the $ν_e\to ν_μ$ channel in matter. Although it is known that the effects of new interactions can only act as a perturbation to the leading oscillation parameters, we find that great care needs to be taken when drawing conclusions regarding the strength of new couplings from oscillation measurements.