COHERENT constraints on nonstandard neutrino interactions

TL;DR

This paper uses COHERENT experiment data to set constraints on nonstandard neutrino interactions, especially focusing on the effects of a light vector mediator and the impact of parameter degeneracies.

Contribution

It provides new bounds on the coupling of light mediators inducing nonstandard neutrino interactions and analyzes how degeneracies affect these constraints.

Findings

Constraints on mediator coupling for mediators lighter than 50 MeV.

Degeneracies weaken constraints for heavier mediators.

COHERENT data constrains NSI parameters relevant for Earth matter propagation.

Abstract

Coherent elastic neutrino-nucleus scattering consistent with the standard model has been observed by the COHERENT experiment. We study nonstandard neutrino interactions using the detected spectrum. For the case in which the nonstandard interactions (NSI) are induced by a vector mediator lighter than 50 MeV, we obtain constraints on the coupling of the mediator. For a heavier mediator, we find that degeneracies between the NSI parameters severely weaken the constraints. However, these degeneracies do not affect COHERENT constraints on the effective NSI parameters for matter propagation in the Earth.