Direct excitation of the “dark”b3Πstate predicted by deperturbation analysis of theA

Abstract

The diode-laser-induced fluorescence spectra b 3 + =0 → X 1 + originated from the rovibronic levels of the "dark" triplet b 3 + =0 state of KCs dimers were recorded with a Fourier transform spectrometer with a resolution of 0.03 cm −1 . Term values of 30 rovibronic levels (v * b0 ∈ [14,18]; J ∈ [47,134]) below the minimum of perturbing A 1 + state were determined with 0.003-0.01 cm −1 uncertainty. The optimal excitation and detection lines for very weak spin-forbidden b 3 + =0 -X 1 + transitions have been properly predicted in the framework of the coupled-channels deperturbation analysis recently performed for the singlet-triplet A 1 + -b 3 + =0,1,2 complex [A. Kruzins et al., Phys. Rev. A 81, 042509 (2010)]. The lowest observed triplet level has only 8.6% of singlet admixture.

Extended Fourier-transform spectroscopy studies and deperturbation analysis of the spin-orbit coupled A1Σ+ and b3Π states in RbCs

“…8 for K 2 . Further improvement of the CC approach and elaboration of the FT spectroscopy experiments made it possible to reproduce the data close to the experimental accuracy of about 0.01 cm −1 , for example, in NaRb, 9 NaCs, 10 KCs, [11][12][13] Cs 2 , 14 and Rb 2 . 15 The present work is focused on the A − b complex of the RbCs molecule which is often used to produce cold and ultracold species, see Table I in Ref.…”

Global analysis of data on the spin-orbit-coupledA1Σu+andBai1, Ahmed2, Beser3 et al. 2011Phys. Rev. ASelf Cite

“…At the University of Latvia, FTS data on the A and b states of Cs 2 have been obtained recently in the process of analyzing the A/b → X laser-induced fluorescence (LIF) spectra of KCs [25,26] and RbCs [27] molecules. In these spectra, along with transitions in KCs and RbCs, the A/b → X LIF spectra of Cs 2 molecules were present as well.…”

“…Recently, the methods available for analyzing and modeling spectroscopic data on highly perturbed states have been extended [18][19][20][21][22][23][24][25][26][27] As is evident from the discussion below, each effort to perform a "global analysis" of all available data on these two electronic states raises additional questions about what Hamiltonian elements and functions are required, and what data is required to determine the parameters so as to achieve a fit with residuals comparable to experimental uncertainties. There has been impresssive progress in data acquisition and analysis for the heteronuclear A and b states from work on NaK [28][29][30][31][32] to more recent work on NaRb [19,23], NaCs [24], KCs [25,26], and RbCs [21,27]. For NaRb, NaCs, and KCs, vibrational assignments of both states have been reliably determined, and the perturbative interactions have been modeled to an accuracy of 0.01 cm −1 or better.…”

The $a^3Σ^+$ state of KCs revisited: hyperfine structure analysis and potential refinement

“…Several higher electronic states were also extensively studied: D(2) 1 Π [14,15], (4) 1 Π [16], (5) 1 Π [17], C(3) 1 Σ + [18], (4) 1 Σ + [19,20], and (6) 1 Σ + [21,22]. A number of excited states studies were carried out by advanced multi-channel deperturbation models, which managed to reach the experimental accuracy of about 0.01 cm −1 even for heavily spin-orbit coupled systems [9,10,15,22].…”