We perform calculations of the dependence of nuclear magnetic moments on quark masses and obtain limits on the variation of the ratio of quark mass and strong interaction scale (m_q/Lambda_{ QCD}) from recent atomic clock experiments with hyperfine transitions in H, Rb, Cs, Yb+, Hg+ and optical transition in Hg+. Experiments with Cd+, deuterium/hydrogen, molecule SF_6, Zeeman transitions in He_3/Xe are also discussed.
Categories: physics.atom-ph hep-ph nucl-th