The neutron electric dipole form factor in the perturbative chiral quark   model
  We calculate the electric dipole form factor of the neutron in a perturbative chiral quark model, parameterizing CP-violation of generic origin by means of effective electric dipole moments of the constituent quarks and their CP-violating couplings to the chiral fields. We discuss the relation of these effective parameters to more fundamental ones such as the intrinsic electric and chromoelectric dipole moments of quarks and the Weinberg parameter. From the existing experimental upper limits on the neutron EDM we derive constraints on these CP-violating parameters. 
Claudio Dib, Amand Faessler, Thomas Gutsche, Sergey Kovalenko, Jan   Kuckei, Valery E. Lyubovitskij, Kem Pumsa-ard