Saturation spectra of low lying states of Nitrogen: reconciling experiment with theory

TL;DR

This paper reinterprets saturation spectra of nitrogen's low-lying states, resolving discrepancies between experimental hyperfine constants and theoretical predictions by proposing a new interpretation of weak spectral lines as crossover signals.

Contribution

It introduces a novel interpretation of spectral lines as crossover signals, aligning experimental data with ab initio theoretical values.

Findings

Reinterpreted weak spectral lines as crossover signals.

Achieved good agreement between experimental and theoretical hyperfine constants.

Resolved previous discrepancies in nitrogen hyperfine spectra.

Abstract

The hyperfine constants of the levels 2p2(3P)3s 4P_J, 2p2(3P)3p 4Po_J and 2p2(3P)3p 4Do_J, deduced by Jennerich et al. [Eur. Phys. J. D 40 (2006) 81] from the observed hyperfine structures of the transitions 2p2(3P)3s 4P_J - 2p2(3P)3p 4Po_J' and 2p2(3P)3s 4P_J - 2p2(3P)3p 4Do_J' recorded by saturation spectroscopy in the near-infrared, strongly disagree with the ab initio values of J\"onsson et al. [J. Phys. B: At. Mol. Opt. Phys. 43 (2010) 115006]. We propose a new interpretation of the recorded weak spectral lines. If the latter are indeed reinterpreted as crossover signals, a new set of experimental hyperfine constants is deduced, in very good agreement with the ab initio predictions.