Precision physics of simple atoms and constraints on a light boson with ultraweak coupling.

Constraint on spin-dependent and spin-independent Yukawa potential at atomic scale is developed. That covers constraints on a coupling constant of an additional photon γ* and a pseudovector boson. The mass range considered is from 1  eV/c2 to 1  MeV/c2. The strongest constraint on a coupling constant α' is at the level of a few parts in 10913) (for γ*) and below one part in 10(16) (for a pseudovector) corresponding to mass below 1  keV/c2. The constraints are derived from low-energy tests of quantum electrodynamics and are based on spectroscopic data on light hydrogenlike atoms and experiments with magnetic moments of leptons and light nuclei.