Potential measurement of the weak mixing angle with neutrino-electron scattering at low energy

TL;DR

This paper explores measuring the weak mixing angle using low-energy neutrino-electron scattering, aiming for high precision with a large water Cherenkov detector and a proton beam dump source.

Contribution

It proposes a novel experimental setup to measure sin^2 theta_W at low momentum transfer with unprecedented precision close to LEP-I results.

Findings

Achieves 0.24% precision in measuring sin^2 theta_W

Utilizes a 100 kt water Cherenkov detector with 20 million events

Demonstrates feasibility of low-energy weak mixing angle measurement

Abstract

We study the possibility to measure sin^2 theta_W by neutrino-electron scattering at a value of the momentum transfer Q ~ 30 MeV with a precision of 0.24% which is only a factor three below the one obtained by LEP-I at the Z-pole. The neutrino source is a proton beam dump providing a clean beam from muon decay at rest and the detector is a 100 kt scale water Cerenkov detector, which results in about 20 million signal events.