Improved limit on electron neutrino charge radius through a new evaluation of the weak mixing angle

TL;DR

This paper presents a new, tighter limit on the electron neutrino charge radius by evaluating the weak mixing angle from various scattering measurements, enhancing previous bounds and discussing future experimental prospects.

Contribution

It provides the first combined fit of all relevant scattering data to refine the electron neutrino charge radius and weak mixing angle measurements at low energies.

Findings

Weak mixing angle found to be sin^2 θ_W=0.259 ± 0.025

Electron neutrino charge radius squared constrained to -0.13×10^-32 cm^2 < r^2 < 3.32×10^-32 cm^2

Results improve upon previous analyses

Abstract

We have obtained a new limit on the electron neutrino effective charge radius from a new evaluation of the weak mixing angle by a combined fit of all electron-(anti)neutrino electron elastic scattering measurements. Weak mixing angle is found to be sin^2 theta_W=0.259 \pm 0.025 in the low energy regime below 100 MeV. The electron neutrino charge radius squared is bounded to be in the range -0.13 10^-32 cm^2 < r^2 < 3.32 10^-32 cm^2 at 90 % C.L. Both results improve previously published analyses. We also discuss perspectives of future experiments to improve these constraints.