The double minimum E1Σu+ state in caesium dimer was investigated by analysing spectra of the E1Σu+← X1Σg+ band system, simplified by polarisation labelling. A total of 6727 rotationally resolved transitions to levels situated in the inner well and above the internal barrier were identified and a potential energy curve allowing to reproduce their energies was constructed using the Fourier grid Hamiltonian and inverted perturbation approach methods. The unambiguousness of the potential curve in view of lack of data related to levels located in the outer well is discussed.
@article{arxiv.2501.05271,
title = {The double minimum E(3)$^1\Sigma^{+}_{\mathrm{u}}$ state in Cs$_2$},
author = {W. Jastrzebski and P. Kowalczyk and J. Szczepkowski and A. Pashov},
journal= {arXiv preprint arXiv:2501.05271},
year = {2025}
}