A channelled particle, which moves in a crystal, alongside with electromagnetic interaction also experiences weak interaction with electrons and nuclei, as well as strong interaction with nuclei. Measurements of polarization vector and angular distribution of particles scattered by axes (planes) of unbent crystal enable to obtain limits for the EDM value and for values of constants describing P- and T-odd interactions. The same measurements also allow studying magnetic dipole moment of charged and neutral particles. Investigation of left-right asymmetry by the use of two unbent crystals makes it possible to measure EDM, MDM and other constants without studying the angular distribution of decay products of scattered particles: it is sufficient to measure the intensity of flow of particles experienced double scattering. Spin precession of channelled particles in bent crystals at the LHC gives unique possibility for measurement of constants determining T-odd, P-odd (CP) violating interactions and P-odd, T-even interactions of baryons with electrons and nucleus (nucleons), similarly to the possibility of measuring electric and magnetic moments of charm, beauty and strange charged baryons. Methods to separate P-noninvariant rotation from the MDM- and EDM-induced (T-odd) spin rotations are discussed.
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