The Weak Neutral Current

TL;DR

This review discusses low-energy electroweak neutral current measurements, their role in testing the Standard Model, and their importance in exploring new physics beyond it, including future experimental and theoretical challenges.

Contribution

It provides a comprehensive overview of low-energy neutral current experiments, emphasizing their significance in precision tests and new physics searches within the Standard Model framework.

Findings

Neutral current measurements determine the weak mixing angle.

These measurements are competitive with Z-resonance results.

They help discriminate between Standard Model extensions like supersymmetry.

Abstract

This is a review of electroweak precision physics with particular emphasis on low-energy precision measurements in the neutral current sector of the electroweak theory and includes future experimental prospects and the theoretical challenges one faces to interpret these observables. Within the minimal Standard Model they serve as determinations of the weak mixing angle which are competitive with and complementary to those obtained near the Z-resonance. In the context of new physics beyond the Standard Model these measurements are crucial to discriminate between models and to reduce the allowed parameter space within a given model. We illustrate this for the minimal supersymmetric Standard Model with or without R-parity.