Parity-Even and Time-Reversal-Odd Neutron Optical Potential in Spinning
  Matter Induced by Gravitational Torsion
  Recent theoretical work has shown that spin $1/2$ particles moving through
unpolarized matter which sources torsion fields experience a new type of
parity-even and time-reversal-odd optical potential if the matter is spinning
in the lab frame. This new type of optical potential can be sought
experimentally using the helicity dependence of the total cross sections for
longitudinally polarized neutrons moving through a rotating cylindrical target.
In combination with recent experimental constraints on short-range P--odd,
T--even torsion interactions derived from polarized neutron spin rotation in
matter one can derive separate constraints on the time components of scalar and
pseudoscalar torsion fields in matter. We estimate the sensitivity achievable
in such an experiment and briefly outline some of the potential sources of
systematic error to be considered in any future experimental search for this
effect.
