Speaker
Detlev Gotta
Description
An electric dipole moment (EDM) aligned with the spin of a fundamental
particle violates both parity conservation and time reversal
invariance, or, via the presumed CPT conservation, CP invariance.
Standard Model predictions are much below current or anticipated
experimental sensitivity levels; an observation within the next
generation of searches will represent a new signature of CP violation
and possibly contribute to our understanding of the matter-antimatter
asymmetry of the universe.
This presentation outlines the possibility to use an electromagnetic
storage ring to directly probe charged particles for an EDM at a
sensitivity level approaching 10^-29 e.cm.
Every sensitive electric dipole moment measurement proceeds in three
steps: preparation of an intense highly polarized ensemble of
particles; interaction of the EDM with a strong electric field for as
long as possible; measurement of the spin evolution. For the storage
ring technique, a polarized beam is accelerated and injected into the
storage ring. Here the polarization is rotated to point along the
momentum of the particles. While circling the ring the particles
interact with a combination of a vertically oriented magnetic field
and a radially oriented electric field. With a carefully controlled
combination of electric and magnetic field strengths, the precession
of the polarization caused by the interaction of the magnetic moment
can be halted. The interaction between the EDM and the electric field
causes the polarization to develop a vertical component, out of the
ring plane.
The setup, status and R&D efforts of several experimental EDM
searches based on the storage ring technique will be discussed,
including those on the muon, proton and deuteron.
Primary author
Dr
Gerco Onderwater
(KVI, University of Groningen)
