muEDM: Towards a search for the muon electric dipole moment at PSI using the frozen-spin technique

TL;DR

The paper proposes a novel muon EDM search at PSI using the frozen-spin technique, aiming for unprecedented sensitivity and discussing experimental concepts and preparatory studies.

Contribution

It introduces the first dedicated muon EDM experiment employing the frozen-spin method at PSI, significantly improving sensitivity over previous limits.

Findings

Characterization of a potential muon beamline at PSI.

Measurement of Coulomb scattering of low-momentum positrons.

Development of experimental concepts for the muEDM search.

Abstract

The search for a permanent electric dipole moment (EDM) of the muon is an excellent probe for physics beyond the Standard Model of particle physics. We propose the first dedicated muon EDM search employing the frozen-spin technique at the Paul Scherrer Institute (PSI), Switzerland, with a sensitivity of $6 \times 10^{-23}~e\!\cdot\!\mathrm{cm}$, improving the current best limit set by the E821 experiment at Brookhaven National Laboratory by more than three orders of magnitude. In preparation for a high precision experiment to measure the muon EDM, several R&D studies have been performed at PSI: the characterisation of a possible beamline to host the experiment for the muon beam injection study and the measurement of the multiple Coulomb scattering of positrons in potential detector materials at low momenta for the positron tracking scheme development. This paper discusses experimental concepts and the current status of the muEDM experiment at PSI.