Isotope shift metrology in the deep-UV region has been performed for all bosonic isotopes of mercury with a zero nuclear spin, using the technique of frequency-comb referenced, wavelength-modulated, saturated absorption spectroscopy. The absolute center frequencies of the 6s2 1S0 → 6s6p 3P1 transition have been measured with precision in the range of 2.5–5.9 10−12 in temperature-stabilized Hg vapor samples with natural abundances. Frequency shifts in four isotope pairs have been determined with unprecedented accuracy, the global uncertainty being improved by a factor greater than 20 with respect to the best experimental data of the past literature. Our dataset, when combined with previous measurements on the 6s6p 3P2 → 6s7s 3S1 transition at 546 nm, allows us to build a King plot that reveals a nonlinearity with a statistical significance of 4.6σ.
Isotope shift spectroscopy in mercury vapors: A promising alternative to ytterbium for new physics search
Stefania Gravina;Antonio Castrillo;Livio Gianfrani
2026
Abstract
Isotope shift metrology in the deep-UV region has been performed for all bosonic isotopes of mercury with a zero nuclear spin, using the technique of frequency-comb referenced, wavelength-modulated, saturated absorption spectroscopy. The absolute center frequencies of the 6s2 1S0 → 6s6p 3P1 transition have been measured with precision in the range of 2.5–5.9 10−12 in temperature-stabilized Hg vapor samples with natural abundances. Frequency shifts in four isotope pairs have been determined with unprecedented accuracy, the global uncertainty being improved by a factor greater than 20 with respect to the best experimental data of the past literature. Our dataset, when combined with previous measurements on the 6s6p 3P2 → 6s7s 3S1 transition at 546 nm, allows us to build a King plot that reveals a nonlinearity with a statistical significance of 4.6σ.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
