Constraints on a long-range spin-dependent interaction from precision atomic physics

Abstract

We present a phenomenological constraint on a pseudovector light boson beyond the Standard Model, which can induce a long-range spin-dependent interaction ${\alpha }^{\prime \prime }({\mathbf{s}}_1\cdot {\mathbf{s}}_2){\mathrm{e}}^{-\lambda r}/r$. In the range of masses from $4\mathrm{keV}/c^2$ to those related to macroscopic distances (of ${\lambda }^{-1}\sim 1$cm) the spin-dependent coupling constant ${\alpha }^{\prime \prime }$ of the electron-muon interaction is constrained at the level below a part in $10^{15}$. The constraint is weakened while extending to higher masses. The strongest constraint is related to the lepton-lepton interaction. Constraints on spin-dependent interactions of some other particles are also discussed. The results are obtained from data on the HFS interval of the ground state in muonium and a few other light hydrogen-like atoms.

Comments: Cross references to Arxiv are updated (arXiv:1005.4859, arXiv:1005.4872)