Searches for Permanent Electric Dipole Moments.pdf

Searches for Permanent Electric Dipole Moments Contribution to the proceedings of HQL06, Munich, October 16th-20th 2006 Klaus Jungmann 7 0 Kernfysisch Versneller Instituut 0 University of Groningen 2 NL-9747 AA Groningen, THE NETHERLANDS r a M 8 1 1 Introduction 1 v The Standard Model (SM) of particle physics provides a theoretical framework which 1 3 allows to describe all observations in particle physics to date. Even those recent 0 observations in neutrino physics which strongly indicate the existence of neutrino os- 3 cillations can be accommodated with small modification. However, contrary to this 0 7 the great success of the SM there remains a number of most intriguing questions in 0 modern physics to which the SM can not provide further clues about the underlying / x physical processes, although the facts are can be described often to very high accuracy. e - Among those puzzling issue are the existence of exactly three generations of funda- p e mental particles, i.e. quarks and leptons, and the hierarchy of the masses of these h fundamental fermions. In addition, the electro-weak SM has a rather large number : v of some 27 free parameters, which all need to be extracted from experiments[1]. i X In modern physics - and in particular in the SM - symmetries play an important r and central role. We know that global symmetries relate to conservation laws and local a symmetries give forces [2]. Within the SM the physical origin of the observed breaking of discrete symmetries in weak interactio