Comments on "Limits on possible new nucleon monopole-dipole interactions from the spin relaxation rate of polarized 3^3He gas"

In the article "Limits on possible new nucleon monopole-dipole interactions from the spin relaxation rate of polarized $^3$He gas", new limits on short-range, Axion-like interactions are presented. In this comment it is shown that the theoretical treatement of the data overestimates the sensitivity of the proposed method. We provide the corrected limits

Frequency shifts and relaxation rates for spin 1/2 particles moving in electromagnetic fields

We discuss the behaviour of the Larmor frequency shift and the longitudinal relaxation rate due to non-uniform electromagnetic fields on an assembly of spin 1/2 particles, in adiabatic and nonadiabatic regimes. We also show some general relations between the various frequency shifts and between the frequency shifts and relaxation rates. The remarkable feature of all our results is that they were obtained without any specific assumptions on the explicit form of the correlation functions of the fields. Hence, we expect that our results are valid both for diffusive and ballistic regime of motion and arbitrary cell shapes and surface scattering. These results can then be applied to a wide variety of realistic systems

Constraining short-range spin-dependent forces with polarized helium 3 at the Laue-Langevin Institute

We have searched for a short-range spin-dependent interaction mediated by a hypothetical light scalar boson with CP-violating couplings to the neutron using the spin relaxation of hyperpolarized $^3$He. The walls of the $^3$He cell would generate a depolarizing pseudomagnetic field.Comment: Twelfth Conference on the Intersections of Particle and Nuclear Physics (CIPANP2015), Vail Marriott Mountain Resort, Vail, Colorado, US