Fourier transform spectroscopy, relativistic electronic structure calculation, and coupled-channel deperturbation analysis of the fully mixed $A^1{\Sigma }_u^{+}$ and $b^3{\Pi }_u$ states of Cs${}_2$

Abstract

The 4503 rovibronic term values belonging to the mutually perturbed $A^1{\Sigma }_u^{+}$ and $b^3{\Pi }_u$ states of Cs${}_2$ were extracted from laser induced fluorescence (LIF) $A\sim b\to X^1{\Sigma }_g^{+}$ Fourier transform spectra with the 0.01 cm${}^{-1}$ uncertainty. The experimental term values of the $A^1{\Sigma }_u^{+}\sim b^3{\Pi }_u$ complex covering the rotational levels $J\in [4,395]$ in the excitation energy range $[9655,13630]$ cm${}^{-1}$ were involved into coupled-channel (CC) deperturbation analysis. The deperturbation model takes explicitly into account spin-orbit coupling of the $A^1{\Sigma }_u^{+}(A{0}_u^{+})$ and $b^3{\Pi }_{0_u}^{+}(b{0}_u^{+})$ states as well as spin-rotational interaction between the $\Omega =0$, $1$ and $2$ components of the $b^3{\Pi }_{{\Omega }_u}^{+}$ state. The \emph{ab initio} relativistic calculations on the low-lying electronic states of Cs${}_2$ were accomplished in the framework of Fock space relativistic coupled cluster (FSRCC) approach to provide the interatomic potentials of the interacting $A{0}_u^{+}$ and $b{0}_u^{+}$ states as well as the relevant $A\sim b$ spin-orbit coupling function. To validate the present CC deperturbation analysis solely obtained by energy-based data, the $A\sim b\to X(v_X^{\prime \prime })$ LIF intensity distributions were measured and compared with their theoretical counterparts obtained by means of the non-adiabatic vibrational wave functions of the $A\sim b$ complex and the FSRCC $A\sim b\to X$ transition dipole moments calculated by the finite-field method.

13 pages, 13 figures

References in corpus (10)

• Quantum Gas of Deeply Bound Ground State Molecules
• Quantum gas of rovibronic ground-state molecules in an optical lattice
• Optical pumping and vibrational cooling of molecules
• Precision Test of Mass Ratio Variations with Lattice-Confined Ultracold Molecules
• Duo: a general program for calculating spectra of diatomic molecules
• Enhanced sensitivity to variation of $m_e/m_p$ in molecular spectra
• Measurement of the variation of electron-to-proton mass ratio using ultracold molecules produced from laser-cooled atoms
• Dark resonances for ground state transfer of molecular quantum gases
• Global analysis of data on the spin-orbit coupled $A^1{\Sigma }_u^{+}$ and $b^3{\Pi }_u$ states of Cs2
• Precision molecular spectroscopy for ground state transfer of molecular quantum gases

Cited by in corpus (3)

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• Fourier-transform spectroscopy and relativistic electronic structure calculation on the $c^3{\Sigma }^{+}$ state of KCs
• Genetics-based deperturbation analysis for the spin-orbit coupled ${\mathrm{A}}^1{\Sigma }^{+}$ and ${\mathrm{b}}^3{\Pi }_{0^{+}}$ states of LiRb