Stability of the proton-to-electron mass ratio

Abstract

We report a limit on the fractional temporal variation of the proton-to-electron mass ratio as, obtained by comparing the frequency of a rovibrational transition in SF6 with the fundamental hyperfine transition in Cs. The SF6 transition was accessed using a CO2 laser to interrogate spatial 2-photon Ramsey fringes. The atomic transition was accessed using a primary standard controlled with a Cs fountain. This result is direct and model-free.

References in corpus (2)

• Enhanced sensitivity to time-variation of m_p/m_e in the inversion spectrum of ammonia
• Laboratory Limits on Temporal Variations of Fundamental Constants: An Update

Cited by in corpus (1)

• $\Lambda$-doublet spectra of diatomic radicals and their dependence on fundamental constants