Triatomic Hydrogen
Welcome to the Triatomic Hydrogen Group at the Department of Molecular and Optical Physics - University of Freiburg, Germany

Rotational Channel Interactions of Vibrationally Excited np-Rydberg States of the Triatomic Hydrogen Molecule
R. Reichle, I. Mistrík, U. Müller and H. Helm
Department of Molecular and Optical Physics, Albert-Ludwigs-Universität, Hermann-Herder-Strasse 3, D-79104  Freiburg, Germany


We have carried out a precise measurement of the wavelength dependence of the two-step photoionization cross section of triatomic hydrogen via the 3s2 A1' Rydberg state at energies beyond the ionization limits that belong to the first symmetric-stretch excited vibrational state \{1,00\} of the ion core. In this energy region, rotational and vibrational channel couplings due to the interaction between the outer p electron and the H3+ core are expected. We find strong coupling between the two p series with total angular momentum N=2 which converge to the rotational levels N+=1 and 3 of the underlying H3 + \{1,00\} core. Surprisingly, regular perturbations are also detected in the symmetric-stretch-excited N=1 p series. Rydberg levels of the ndE' \{1,00\} series are identified as the perturbing channel. This implies a change in the orbital angular momentum of the Rydberg electron during the short-range interaction. The experimental spectra are analyzed in two-channel quantum-defect models. Eigenchannel quantum defects, coupling constants, and transition moment ratios are determined and compared to the results of recent ab initio calculations. ©1999 The American Physical Society

©1999 Physical Review A 60, 3929 (1999)

DOI: 10.1103/PhysRevA.60.3929
PACS: 33.80.Rv, 33.80.Eh

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