Elastic neutrino-electron scattering perspectives at nuclear reactors

TL;DR

This paper evaluates the potential of reactor neutrino experiments to measure the weak mixing angle and probe new physics through elastic neutrino-electron scattering, showing promising sensitivities for current and future setups.

Contribution

It provides the first detailed sensitivity analysis of EνES at reactor experiments for measuring the weak mixing angle and constraining non-standard neutrino interactions.

Findings

CLOUD and TAO could surpass current global measurements of the weak mixing angle.

DANSS is expected to outperform the TEXONO benchmark in measuring the weak mixing angle.

Projected limits on neutrino magnetic moments and NSI are competitive with existing bounds.

Abstract

The determination of the weak mixing angle, $\sin^2\theta_W$, at low momentum transfers remains a powerful test of the Standard Model and its potential new physics extensions. In this paper, we explore some physics opportunities at present and future reactor neutrino experiments through elastic neutrino-electron scattering (E$\nu$ES). We assess the expected sensitivity to the weak mixing angle considering the CLOUD, TAO, and DANSS experimental configurations. We find that both CLOUD and TAO may achieve a precision that surpasses the current global fit from reactor experiments, while DANSS alone is expected to surpass the benchmark precision set by TEXONO measurement of the weak mixing angle. Additionally, we derive projected upper limits for the non-standard neutrino interactions (NSI), effective neutrino magnetic moment ($\mu_\nu$) and translate these into constraints on the neutrino transition magnetic moments ($\Lambda_i$). Our results demonstrate the physics potential of the E$\nu$ES channel at current and upcoming reactor-based neutrino experiments.