Left-right asymmetry in polarised neutron scattering

In the paper the two principal origins of the appearance of LRA in the pola rised neutron scattering are discussed, the space (P) and the time (T) pari ty violations. The first takes place for instance, in crystals without a ce ntre of symmetry, or in the presence of an electric field. The second occur s in a ferromagnet, or in other magnetic structures under applied magnetic fields. Several examples of P- and T-symmetry breaking are discussed using results from polarised neutron scattering experiments on helical magnetic s tructures, critical spin fluctuations and spin waves. A short review of exp erimental work involving the static and dynamical chirality is given. (C) 1 999 Elsevier Science B.V. All rights reserved.