A first experimental limit on in-matter torsion from neutron spin rotation in liquid 4He

We report the first experimental upper bound to our knowledge on possible in-matter torsion interactions of the neutron from a recent search for parity violation in neutron spin rotation in liquid He-4. Our experiment constrains a coefficient zeta consisting of a linear combination of parameters involving the time components of the torsion fields T-mu and A(mu) from the nucleons and electrons in helium which violates parity. We report an upper bound of |zeta| < 5.4 x 10(-16) GeV at 68% confidence level and indicate other physical processes that could be analyzed to constrain in-matter torsion. (C) 2014 Elsevier B.V.