Detailed spectroscopy of the Cs2a3Σu+state and implications for measurement

Abstract

We present spectroscopic data on moderately bound levels in the Cs2 a 3 Σ + u state. The data have sufficient resolution to be sensitive to rotational and second-order spin-orbit splittings as well as hyperfine and vibrational structure. Quantum numbers are assigned to the levels via selection rules and a global fit to other available data for the a 3 Σ + u and coupled X 1 Σ + g states. The analysis focuses in particular on nearly degenerate pairs of a and X state levels, energy differences between which can be highly sensitive to possible variations in the electron-to-proton mass ratio (cf. DeMille et al., Phys. Rev. Lett. 100, 043202 (2008)). We also characterize the electric (E1) and magnetic (M1) dipole transition strengths between nearly degenerate a and X ro-vibrational levels and find that both types of transitions are feasible with current technology and could give complementary information.

Hyperfine and vibrational structure of weakly bound levels of the lowest1gstate of molecular87Rb2

“…Since g/u parity does not apply in the atomic limit, this transformation effectively couples g and u states, and singlet and triplet states, as in the case of the X 1 + g and a 3 + u states of Cs 2 in Ref. [45]. A discussion of the details is beyond the scope of this work since the analysis of the experimental data could not be extended into the highly congested spectral region near the dissociation limit.…”

Bichromatic Photoassociation Spectroscopy for the Determination of Rotational Constants of Cs2 0 u + Long-Range State below the 6S1/2 + 6P1/2 Asymptote

“…In this sense, the PAS is often advantageous in the detection of molecular ro-vibrational energy levels and hyperfine structures over traditional thermo-luminescence spectroscopy or fluorescence spectroscopy techniques [20]. PAS has enabled one to obtain information of molecular structures [21], to determine the long-range behaviour of the potential energy curves and molecular constants [22,23], and to measure the s-wave scattering lengths [4] as well as the time variations of fundamental physical constants [24].…”

Experimental study of the 61Σg+ state of the rubidium dimer

“…This gives rise to unusual properties including extremely long-range vibrations, large dipole moments, and a near-infinite manifold of vibrational states. They are attractive for the detection of ultracold molecules using resonantly enhanced multiphoton ionization (REMPI) technique [67][68][69][70][71][72][73] in a broad internuclear range. They can also be used for Raman transfer of molecular population from large internuclear distance to the covalent bonding region.…”