Observation and modelling of bound-free transitions to the $X^1{\Sigma }^{+}$ and $a^3{\Sigma }^{+}$ states of KCs

Abstract

The oscillation continuum in laser-induced fluorescence spectra of bound-free $c^3{\Sigma }^{+}\to a^3{\Sigma }^{+}$ and (4)${}^1{\Sigma }^{+}\to X^1{\Sigma }^{+}$ transitions of the KCs molecule were recorded by Fourier-transform spectrometer and modelled under the adiabatic approximation. The required interatomic potentials for ground $a^3{\Sigma }^{+}$ and $X^1{\Sigma }^{+}$ states were reconstructed in an analytical Chebishev-polynomial-expansion form in the framework of the regularization direct-potential-fit procedure based on the simultaneous consideration of experimental line positions from [R. Ferber et al, Phys. Rev. A, \textbf{80}, 062501 (2009)] and the present \emph{ab initio} calculation of short-range repulsive potential data. It was proved that the repulsive part over dissociation limit of the derived $a^3{\Sigma }^{+}$ potential reproduces the experiment better than the potentials reported in literature. It is also shown that all empirical and semi-empirical potentials available for the $X^1{\Sigma }^{+}$ state reproduce the bound-free (4)${}^1{\Sigma }^{+}\to X^1{\Sigma }^{+}$ spectrum with equal quality in the range of observations.

9 pages, 7 figures

References in corpus (3)

• Reactions of ultracold alkali metal dimers
• Observation of interspecies Feshbach resonances in an ultracold ${}^{39}$K-${}^{133}$Cs mixture and refinement of interaction potentials
• Feshbach resonances, molecular bound states and prospects of ultracold molecule formation in mixtures of ultracold K and Cs

Cited by in corpus (1)

• Intensities of KCs $E(4{)}^1{\Sigma }^{+}\to (a^3{\Sigma }^{+},X^1{\Sigma }^{+})$ band system up to dissociation threshold: an interplay between spin-orbit, hyperfine and rovibronic coupling effects