Scope of the Workshop

The aim of the workshop is to bring together scientists strongly motivated to participate in a search for a muon electric dipole moment (EDM) using the frozen spin technique at PSI. Assuming CPT invariance, electric dipole moments violate the combined symmetry of charge and parity (CP) and are thus of particular interest as probes for CP violation beyond the standard model. Presuming lepton flavor universality (LFU) the stringent limit on the electron EDM (de < 1.1×10-29 e•cm) [1], measured using molecules, translates by mass scaling also to dµ < 2.2×10-27 e•cm, a value about 8 orders of magnitude smaller than the current direct upper limit of dµ < 1.8×10-19 e•cm [2]. However, theories that abandon LFU [3] and references therein generally predict much larger values and are of increasing interest in the light of recent deviations from the SM in B-factories measurement of semileptonic meson decays and the muon g-2 discrepancy. Employing the frozen spin technique [4] in a dedicated compact storage ring [5] at PSI would allow an improvement of the current direct limit by 3 orders of magnitude.


[1] ACME collaboration, Nature 562(2018)355

[2] Bennett et al., PRD80(2009)052008

[3] Crivellin et al., PRD98(2018)113002

[4] Farley et al., PRL93(2004)052001

[5] Adelmann et al., JPG37(2010)085001