Temporal variation of the fine structure constant and the strong interaction parameter in the 229Th transition Original Research Article

The very low energy (7.6±0.5 eV) of the long-lived isomer state in 229Th has inspired the idea that the transition between this isomer and the ground state might be used to measure the temporal variation of some fundamental physical constants with great enhanced sensitivity in laboratory. Physicists have used several models to test whether this significantly enhanced sensitivity does exist. However, incongruous conclusions were reached. Based on the formulae derived from Feynman–Hellmann theorem, we reexamine the physics involved in those argument by the relativistic mean field theory. The results show that the correlation between the nuclear strong interaction and Coulomb force is important and cannot be neglected. The sensitivity to variations of fine structure constant, nucleon mass and meson masses could be enhanced by several orders of magnitude in the 229Th transition.