[Triumf-seminars] TRIUMF Colloquium today at 11:00

[TRIUMF Seminars]

Date/Time: Wed 2011-08-03 at 11:00

Location:  Auditorium          

Speaker:   Klaus Kirch (ETH Zürich and Paul Scherrer Institut)

Title:     The search for permanent electric dipole moments

Abstract: While our universe appears to contain much more matter than antimatter, the laws of microscopic physics are mostly symmetric in that respect, i.e. they almost preserve the combined charge and parity symmetry CP. Our Standard Model of particle physics contains some CP violation but this is not sufficient to explain the obvious baryon asymmetry of the universe (BAU). It has been predicted already many years ago that we should find additional CP violation in order to explain the BAU. In most well behaved quantum field theories CP violation is equivalent to time reversal (T) violation because of the conservation of the combined symmetries CPT.

About 60 years ago, Ramsey realized that permanent electric dipole moments of fundamental particles violate, both, parity and time reversal symmetries (and thus CP). Today the non-observation of finite electric dipole moments of various systems so far sets some of the most stringent bounds on physics models that go beyond the Standard Model which, among other things, try to provide the missing CP violation.The talk will start from these considerations, explain measurement principles and give an update on some experimental efforts ongoing today with an emphasis on the search for the electric dipole moment of the neutron (nEDM). I will also introduce the source for ultracold neutrons at PSI and report on the status of the nEDM experiment which is pursued by an international collaboration at PSI.

Stimulants available 15 minutes before the talk.

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