  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.
