T. Madhu Trivikram, M.L. Niu, P. Wcisło, W. Ubachs, E.J. Salumbides
Accurate EF 1 Σ + g - X 1 Σ + g transition energies in molecular hydrogen were determined for transitions originating from levels with highly excited vibrational quantum number, Ν = 11, in the ground electronic state. Doppler-free two-photon spectroscopy was applied on vibrationally excited H * 2 , produced via the photodissociation of H2S, yielding transition frequencies with accuracies of 45 MHz or 0.0015 cm -1 . An important improvement is the enhanced detection efficiency by resonant excitation to autoionizing 7π electronic Rydberg states, resulting in narrow transitions due to reduced ac-Stark effects. Using known EF level energies, the level energies of X(Ν = 11, J = 1, 3-5) states are derived with accuracies of typically 0.002 cm -1 . These experimental values are in excellent agreement with and are more accurate than the results obtained from the most advanced ab initio molecular theory calculations including relativistic and QED contributions. © The Author(s) 2018.
Department of Physics and Astronomy, Vrije Universiteit Amsterdam, De Boelelaan 1081, Amsterdam, 1081 HV, Netherlands; Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, Toruń, 87-100, Poland; Department of Physics, University of San Carlos, Cebu City, 6000, Philippines
