Sensitivity to a variation of m_e/m_p from splittings between ~(12)C_2HD reference frequencies

摘要

The sensitivity to a variation of μ of the 2v_1 and v_1+v_3+v_5 bands transitions of ~(12)C_2HD in the 193-199 THz spectral domain is calculated with an effective Hamiltonian for the Coriolis interaction between the [200(00)~(0e)] and [101(01)~(1e)] energy levels. The frequency splittings between near resonant transitions have sensitivity coefficients to a variation of μ of both signs in the range of 10-10~5. The degeneracy is due to a cancellation of effective rotational intervals with frequency shifts associated to the vibrational band origins, the anharmonicity and the rotation-vibration interactions. The measurements of a temporal drift of a frequency splitting against the Cs hyperfine frequency may constrain the time variation of μ better than the time variations of α, g_(Cs). The systematic frequency shifts are evaluated for intracavity saturated absorption spectroscopy measurements and constrain the measurement of a variation of μ at ～10~(-10). The comparison between measurements of frequency splittings with sensitivity coefficients of both signs may discriminate a variation of μ at ～8×10~(-11).