CANTON-$\mu$ Proposal: A Next-Generation Muon $g-2$ Measurement at Sub-0.1 ppm Precision

TL;DR

The paper proposes a next-generation muon g-2 experiment at HIAF in China aiming for sub-0.1 ppm precision, surpassing Fermilab and testing Standard Model and CPT symmetry with unprecedented sensitivity.

Contribution

It introduces novel measurement approaches using HIAF's intense muon beams to achieve higher precision in muon g-2 experiments beyond current efforts.

Findings

Achieves 0.13 ppm precision in Phase 1 matching Fermilab's current level.

Plans for 0.05 ppm precision in Phase 2 with HIAF upgrade.

Enables sensitive tests of Standard Model and CPT symmetry beyond existing limits.

Abstract

We propose a next-generation precision measurement of the muon anomalous magnetic moment (muon $g-2$), at the High Intensity Heavy-Ion Accelerator Facility (HIAF) in China. The project, named CANTON-$\mu$ (Coherent Anomalous magNetic momenT ObservatioN with muon), represents the first muon $g-2$ experiment aimed at surpassing Fermilab precision. It introduces novel approaches based on HIAF's intense pulsed GeV-scale muon beams, particularly for negative-muon polarity. This work studies the expected muon beam intensity at HIAF, establishing the statistical reach and level of systematic control required to achieve a precision of 0.13 ppm in Phase 1, matching the current Fermilab precision, and 0.05 ppm in Phase 2 with the HIAF upgrade. This precision enables stringent tests of the Standard Model with sensitivity to new physics beyond current collider scales, and offers a uniquely sensitive test of CPT symmetry within the Standard-Model Extension at the $10^{-24}$ GeV level, improving existing limits by more than an order of magnitude.