Constraining Nonstandard Neutrino-Electron Interactions due to a New Light Spin-1 Boson

TL;DR

This paper investigates constraints on a hypothetical light spin-1 boson mediating nonstandard neutrino-electron interactions, using various experimental data to limit its couplings and mass, without assuming gauge symmetry.

Contribution

It provides a model-independent analysis of constraints on a new light spin-1 boson affecting neutrino-electron interactions, considering flavor-conserving and -violating couplings from multiple experiments.

Findings

Constraints depend on the boson's mass and width.

One data set provides stronger bounds depending on parameters.

Complementary limits are derived for flavor-specific couplings.

Abstract

We consider nonstandard interactions of neutrinos with electrons arising from a new light spin-1 particle with mass of tens of GeV or lower and couplings to the neutrinos and electron. This boson is not necessarily a gauge boson and is assumed to have no mixing with standard-model gauge bosons. Adopting a model-independent approach, we study constraints on the flavor-conserving and -violating couplings of the boson with the leptons from a number of experimental data. Specifically, we take into account the (anti)neutrino-electron scattering and e^+ e^- -> nu nubar gamma measurements and keep explicitly the dependence on the new particle mass in all calculations. We find that one of the two sets of data can provide the stronger constraints, depending on the mass and width of the boson. Also, we evaluate complementary constraints on its separate flavor-conserving couplings to the electron and neutrinos from other latest experimental results.