Determination of the spin-spin coupling constant of the HD isotopologue of hydrogen for the estimate of existence of nonelectromagnetic spin-dependent interaction

Abstract

A new experimental value Jpd = 43.115(9) Hz of the spin-spin coupling constant in the HD isotopologue of hydrogen has been obtained. It does not coincide with the value Jpd = 43.31(5) Hz found theoretically by Helgaker et al. in the development of new methods of precise quantum-mechanical calculations at t ≈ 300 K. As was shown by Ledbetter et al., the difference between the experimental and theoretical data for the spinspin coupling constant Jpd in HD allows estimating the limits of existence of anomalous spin-dependent potentials between the nucleons on the atomic scale with orders-of-magnitude higher accuracy than other methods. From the earlier data on this difference (ΔJpd ≈ 0.24 Hz), Ledbetter et al. estimated the upper limit for the mass of pseudoscalar (axion-like) bosons as ma ≤ 1000 eV. By analogy with these estimates, the discrepancy ΔJpd ≈ (0.195 ± 0.051) Hz of the new results can be interpreted as the manifestation of the anomalous interaction. This interaction can be attributed to the exchange of axion-like particles with the mass ma ≈ (800 ± 200) eV.