Experimental determination of the field shift factor and the mass shift coefficient for the 1S0–3P1 spin-forbidden transition at 791 nm in neutral barium

Abstract

The experimental measurements of the isotope shifts (ISs) for the 1S0–3P1 spin-forbidden transition at 791 nm in neutral barium have been carried out with a thermal barium atom beam. The hyperfine structure (HFS) constants a and b of the odd isotopes [Formula: see text]Ba and [Formula: see text]Ba for this transition have been extracted from the experimental results: a([Formula: see text]Ba) = 1149.9(1.0) MHz, b([Formula: see text]Ba)= −41.6(0.5) MHz, a([Formula: see text]Ba) = 1028.0(1.0) MHz, b([Formula: see text]Ba) = −27.5(0.5) MHz. The measured IS results with the reference isotope [Formula: see text]Ba are 183.7(1.0) MHz ([Formula: see text]Ba–[Formula: see text]Ba), 108.5(0.3) MHz ([Formula: see text]Ba–[Formula: see text]Ba) and 218.9(1.0) MHz ([Formula: see text]Ba–[Formula: see text]Ba). Our IS measurements are in good agreement with the previous experiments. The field shift (FS) factor [Formula: see text] and the mass shift (MS) coefficient [Formula: see text] for this spin-forbidden transition have be determined experimentally as −3.19(4) GHz ⋅ fm[Formula: see text] and −242(20) GHz ⋅ amu, respectively. The results provided herein could be used for further checks theoretically and experimentally, and could also contribute to the study on the nuclear structure of the barium isotopic nuclei.