Limits on variations of the quark masses, QCD scale, and fine structure constant

We perform calculations of the dependence of nuclear magnetic moments on quark masses and obtain limits on the variation of the fine structure constant α and (mq/ΛQCD) from recent measurements of hydrogen hyperfine (21 cm) and molecular rotational transitions in quasar absorption systems, atomic clock experiments with hyperfine transitions in H, Rb, Cs, Yb⁺, Hg⁺, and optical transition in Hg⁺. Experiments with Cd⁺, deuterium/hydrogen, molecular SF₆, and Zeeman transitions in ³He/Xe are also discussed.