Structure and dynamics of HD+ in the vicinity of the H+ + D and D+ + H dissociation thresholds: Feshbach resonances and the role of g/u-symmetry breaking.

We report on the measurement and analysis of photoionisation, mass-analysed-threshold-ionisation and pulsed-field-ionisation zero-kinetic-energy photoelectron spectra of HD in the vicinity of the dissociative-ionisation thresholds H + + D(1s) + e − and H(1s) + D + + e − . The spectra were recorded via the v = 11 − 13 vibrational levels of the H ¯ and B ¯ outer wells of the H H ¯ 1 Σ g + and B ′ ′ B ¯ 1 Σ u + states and provide information on the weakly bound levels of the X + 2 Σ g + ground state of HD + with vibrational quantum numbers v + = 16 − 21 and rotational angular-momentum quantum numbers N + = 0 − 10. The spectra also reveal for the first time shape and Feshbach resonances of HD + located energetically above the H + + D(1s) dissociation limit. The structure and dissociation dynamics of the H ¯ and B ¯ states of HD and of the X + 2 Σ g + and A + 2 Σ u + states of HD + near the dissociation thresholds are strongly influenced by the g/u-symmetry breaking caused by the nuclear-mass asymmetry. [ABSTRACT FROM AUTHOR]