Constraining Spacetime Nonmetricity with Neutron Spin Rotation in Liquid He-4
arXiv:1707.09630 · doi:10.1016/j.physletb.2017.07.059
Abstract
General spacetime nonmetricity coupled to neutrons is studied. In this context, it is shown that certain nonmetricity components can generate a rotation of the neutron's spin. Available data on this effect obtained from slow-neutron propagation in liquid helium are used to constrain isotropic nonmetricity components at the level of $10^{-22}\,$GeV. These results represent the first limit on the nonmetricity $ζ^{(6)}_2S_{000}$ parameter as well as the first measurement of nonmetricity inside matter.
5 pages, accepted for publication in Physics Letters B