Modern Status of Searches for nEDM, using Neutron Optics and Diffraction in Noncentrosymmetric Crystals. (Proc. Int. Conf. Neutron Optics (NOP2017))
V.V. Fedorov, V.V. Voronin
Abstract
New neutron-optics effects in crystals, which can be used to study the fundamental properties of neutron are discussed. Predicted and discovered not long ago strong electric fields of strength up to 10^8
or 10^9 V/cm, which in noncentrosymmetric crystals may act on the neutron, provide new possibilities for measuring the neutron electric dipole moment (nEDM) by the crystal-diffraction method and
also become possible to perform a search for pseudomagnetic forces acting on neutrons and violating CP invariance. For the interaction range of such forces lambda < 10^-5 cm, the best constraints on the
product of the scalar and pseudoscalar coupling constants have already been obtained for the interaction induced by the exchange of a light pseudoscalar (axion-like) particle. The present-day status
and prospects of neutron-optics crystal-diffraction experiments aimed at searches for the nEDM and
pseudomagnetic forces are considered.