Gyromagnetic factors and atomic clock constraints on the variation of fundamental constants

Feng Luo , Keith A. Olive , Jean-Philippe Uzan (1)

1 IAP - Institut d'Astrophysique de Paris

We consider the effect of the coupled variations of fundamental constants on the nucleon magnetic moment. The nucleon g-factor enters into the interpretation of the measurements of variations in the fine-structure constant, α, in both the laboratory (through atomic clock measurements) and in astrophysical systems (e.g. through measurements of the 21 cm transitions). A null result can be translated into a limit on the variation of a set of fundamental constants, that is usually reduced to α. However, in specific models, particularly unification models, changes in α are always accompanied by corresponding changes in other fundamental quantities such as the QCD scale, Λ_QCD. This work tracks the changes in the nucleon g-factors induced from changes in Λ_QCD and the light quark masses. In principle, these coupled variations can improve the bounds on the variation of α by an order of magnitude from existing atomic clock and astrophysical measurements. Unfortunately, the calculation of the dependence of g-factors on fundamental parameters is notoriously model-dependent.

Keywords: 12.10.Dm; 06.20.Jr; 06.30.Ft; 21.10.Ky; Unified theories and models of strong and electroweak interactions; Determination of fundamental constants; Time and frequency; Electromagnetic moments; High Energy Physics - Phenomenology; Astrophysics - Cosmology and Extragalactic Astrophysics; Nuclear Theory; Physics - Atomic Physics

Domains: Sciences of the Universe [physics]

Feng Luo, Keith A. Olive, Jean-Philippe Uzan. Gyromagnetic factors and atomic clock constraints on the variation of fundamental constants. Physical Review D, 2011, 84, ⟨10.1103/PhysRevD.84.096004⟩. ⟨insu-03645847⟩