Pinning down electron correlations in RaF via spectroscopy of excited states and high-accuracy relativistic quantum chemistry

Abstract

We report the spectroscopy of the 14 lowest excited electronic states in the radioactive molecule radium monofluoride (RaF). The observed excitation energies are compared with fully relativistic state-of-the-art Fock-space coupled cluster (FS-RCC) calculations, which achieve an agreement of >=99.64% (within ~12 meV) with experiment for all states. Guided by theory, a firm assignment of the angular momentum and term symbol is made for 10 states and a tentative assignment for 4 states. The role of high-order electron correlation and quantum electrodynamics effects in the excitation energy of excited states is studied, found to be important for all states. Establishing the simultaneous accuracy and precision of calculations is an important step for research at the intersection of particle, nuclear, and chemical physics, including searches of physics beyond the Standard Model, for which RaF is a promising probe.

Significant changes compared to previous version with additional experimental data. Accepted for publication under a different title

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Cited by in corpus (8)

• Estimating complete basis set extrapolation error through random walk
• Laser spectroscopy and CP-violation sensitivity of actinium monofluoride
• Ionization potential of radium monofluoride
• Production and spectroscopy of cold radioactive molecules
• Theoretical determination of the ionization potentials of ScF, YF, LaF and AcF
• Relativistic quintuple-zeta basis sets for the s block
• Commissioning and Full Realization of the PLASEN System at BRIF
• Radioactive Molecules as Laboratories of Fundamental Physics