Search for the muon electric dipole moment using frozen-spin technique at PSI

TL;DR

This paper discusses a novel experimental effort at PSI to measure the muon electric dipole moment using a frozen-spin technique, aiming to detect physics beyond the Standard Model related to charge-parity violation.

Contribution

It introduces a dedicated experimental setup employing a 3-T solenoid storage ring and frozen-spin technique to improve sensitivity in muon EDM measurements beyond traditional methods.

Findings

Projected sensitivity of $6\times10^{-23}$ $e\cdot$cm after one year

Potential to probe Standard Model extensions not accessible by muon g-2 experiments

Use of a compact 3-T solenoid storage ring for EDM measurement

Abstract

The presence of a permanent electric dipole moment in an elementary particle implies Charge-Parity symmetry violation and thus could help explain the matter-antimatter asymmetry observed in our universe. Within the context of the Standard Model, the electric dipole moment of elementary particles is extremely small. However, many Standard Model extensions such as supersymmetry predict large electric dipole moments. Recently, the muon electric dipole moment has become a topic of particular interest due to the tensions in the magnetic anomaly of the muon and the electron, and hints of lepton-flavor universality violation in B-meson decays. In this article, we discuss a dedicated effort at the Paul Scherrer Institute in Switzerland to search for the muon electric dipole moment using a 3-T compact solenoid storage ring and the frozen-spin technique. This technique could reach a sensitivity of $6\times10^{-23}$ $e\cdot$cm after a year of data taking with the $p=125$ MeV/$c$ muon beam at the Paul Scherrer Institute. This allows us to probe various Standard Model extensions not reachable by traditional searches using muon $g-2$ storage rings.