Scientific Results

Measurement of the helium 2 P-3(0)-2(3)P(1) fine structure interval

Year: 1999

Authors: Minardi F., Bianchini G., Cancio Pastor P., Giusfredi G., Pavone FS., Inguscio M.

Autors Affiliation: European Laboratory for Non-linear Spectroscopy (LENS), Largo E. Fermi 2, Firenze, 50125, Italy; Istituto Nazionale di Ottica (INO), Largo E. Fermi 6, Firenze, I-50125, Italy

Abstract: We report the most accurate measurement of the helium fine structure splitting. The 2(3)P(0)-2(3)P(1) energy splitting is 29 616 949.7 +/- 2.0 kHz. Laser saturation spectroscopy, heterodyne pure frequency determination, and fluorescence detection were combined in a novel experimental approach. The absence of external perturbing magnetic fields, used in earlier experiments, lends confidence to our determined value and allows us to discriminate between contradictory results previously reported. This result, when combined with expected advances in theory, should yield a new value of the fine structure alpha, which may help clarify a presently puzzling experimental situation. [S0031-9007(99)08416-1].


Volume: 82      Pages from: 1112  to: 1115

KeyWords: Helium; fine-structure; spectroscopy
DOI: 10.1103/PhysRevLett.82.1112

Citations: 77
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