Reactor antineutrinos CE$\nu$NS on germanium: CONUS+ and TEXONO as a new gateway to SM and BSM physics

TL;DR

This paper discusses how reactor-based CE$ u$NS experiments like CONUS+ and TEXONO enhance our understanding of the Standard Model and BSM physics by providing high-precision data to constrain neutrino properties and new interactions.

Contribution

It introduces new constraints on neutrino electromagnetic properties and nonstandard interactions using reactor CE$ u$NS data, strengthening the role of these experiments in fundamental physics tests.

Findings

Validated CE$ u$NS at low energies with reactor data

Set improved bounds on neutrino charge radius and magnetic moment

Provided the best limit on electron neutrino millicharge

Abstract

Coherent elastic neutrino-nucleus scattering (CE$\nu$NS) is a key process for probing Standard Model and beyond the Standard Model (BSM) properties. Following its first detection by the COHERENT Collaboration, recent reactor-based experiments provide a unique opportunity to refine our current understanding. In particular, the high-precision data from CONUS+, combined with the strong bounds from TEXONO, not only validate the CE$\nu$NS process at low energies but also provide improved constraints on the weak mixing angle, neutrino electromagnetic properties (including the charge radius, millicharge, and magnetic moment), and nonstandard interactions and light mediators. We also examine the role of elastic neutrino-electron scattering, which gains significance in certain BSM scenarios and allows us to obtain the best limit for the millicharge of the electron neutrinos. By combining reactor and higher-energy spallation neutron source measurements, this work strengthens CE$\nu$NS as a precision tool for testing the Standard Model and beyond.