Observations of High Vibrational Levels of the 4fσ 41Σ+ u State of H2

Resonantly enhanced multiphoton ionization via the EF 1Σg+, v′ = 6 double-well state has been used to probe the energy region below the third dissociation limit of H2 where several high vibrational levels of the 41Σu+ state are expected. Theoretical ab initio potential energy curves for this state predict a deep inner well and shallow outer well where vibrational levels above v = 8 are expected to exhibit the double-well character of the state. Since the 41Σu+ state has f-state character, transitions to it from the ground state are nominally forbidden. However, the d character of the outer well of the EF 1Σg+ state allows access to this state. We report observations of transitions to the v = 9–12 levels of the 41Σu+ state and compare their energies to predicted energies calculated from an ab initio potential energy curve with adiabatic corrections. Assignments are based on measured energies and linewidths, rotational constants, and expected transition strengths. The amount of agreement between the predicted values and the observations is mixed, with the largest discrepancies arising for the v = 9 level, owing to strong nonadiabatic electronic mixing in this energy region

Observations of High Vibrational Levels of the 4fσ 41Σ+ u State of H2

Resonantly enhanced multiphoton ionization via the EF 1Σg+, v′ = 6 double-well state has been used to probe the energy region below the third dissociation limit of H2 where several high vibrational levels of the 41Σu+ state are expected. Theoretical ab initio potential energy curves for this state predict a deep inner well and shallow outer well where vibrational levels above v = 8 are expected to exhibit the double-well character of the state. Since the 41Σu+ state has f-state character, transitions to it from the ground state are nominally forbidden. However, the d character of the outer well of the EF 1Σg+ state allows access to this state. We report observations of transitions to the v = 9–12 levels of the 41Σu+ state and compare their energies to predicted energies calculated from an ab initio potential energy curve with adiabatic corrections. Assignments are based on measured energies and linewidths, rotational constants, and expected transition strengths. The amount of agreement between the predicted values and the observations is mixed, with the largest discrepancies arising for the v = 9 level, owing to strong nonadiabatic electronic mixing in this energy region

Observations of the high vibrational levels of the B′′B̄ 1Σu+ state of H2

Double-resonance laser spectroscopy via the E F 1Σg+, v\u27=6, J\u27=0-2 state was used to probe the high vibrational levels of the B B-bar 1Σu+ state of molecular hydrogen. Resonantly-enhanced multiphoton ionization spectra were recorded by detecting ion production as a function of energy using a time of flight mass spectrometer. New measurements of energies for the v=51-66 levels for the B B-bar state of H2 are reported, which, taken with previous results, span the v=46-69 vibrational levels. Results for energy levels are compared to theoretical close-coupled calculations [L. Wolniewicz, T. Orlikowski, and G. Staszewska, J. Mol. Spec. 238, 118 (2006)]. The average difference between the 84 measured energies and calculated energies is -3.8 cm-1 with a standard deviation of 5.3 cm-1. This level of agreement showcases the success of the theoretical calculations in accounting for the strong rovibronic mixing of the 1Σu+ and 1Πu+ states. Due to the ion-pair character of the outer well, the observed energies of the vibrational levels below the third dissociation limit smoothly connect with previously observed energies of ion-pair states above this limit. The results provide an opportunity for testing a heavy Rydberg multi-channel quantum defect analysis of the high vibrational states below the third dissociation limit

Observations of the high vibrational levels of the B′′B̄ 1Σu+ state of H2

Double-resonance laser spectroscopy via the E F 1Σg+, v\u27=6, J\u27=0-2 state was used to probe the high vibrational levels of the B B-bar 1Σu+ state of molecular hydrogen. Resonantly-enhanced multiphoton ionization spectra were recorded by detecting ion production as a function of energy using a time of flight mass spectrometer. New measurements of energies for the v=51-66 levels for the B B-bar state of H2 are reported, which, taken with previous results, span the v=46-69 vibrational levels. Results for energy levels are compared to theoretical close-coupled calculations [L. Wolniewicz, T. Orlikowski, and G. Staszewska, J. Mol. Spec. 238, 118 (2006)]. The average difference between the 84 measured energies and calculated energies is -3.8 cm-1 with a standard deviation of 5.3 cm-1. This level of agreement showcases the success of the theoretical calculations in accounting for the strong rovibronic mixing of the 1Σu+ and 1Πu+ states. Due to the ion-pair character of the outer well, the observed energies of the vibrational levels below the third dissociation limit smoothly connect with previously observed energies of ion-pair states above this limit. The results provide an opportunity for testing a heavy Rydberg multi-channel quantum defect analysis of the high vibrational states below the third dissociation limit

Continuity of heavy Rydberg behaviour in the ungerade ion-pair states of H 2

Heavy Rydberg behaviour and absolute quantum defects are reported for resonances in the ungerade manifold of H2 above the (1s, 3l) dissociation limit. The continuity of the vibrational progression of the B\u27\u27B-bar state through the crossing with the 3p asymptote is demonstrated and a predominantly diabatic picture of the vibrational motion emerges, indicating that the ion-pair resonances possess little 61Σu+ state character

Double resonance spectroscopy of the D1Πu+ and B\u27\u27B-bar 1Σu+ states near the third dissociation threshold of H2

Double-resonance laser spectroscopy via the E, F 1Σg+, v\u27 = 6, J\u27 state was used to probe the energy region below the third dissociation limit of molecular hydrogen. Resonantly enhanced multi-photon ionization spectra were recorded by detecting ion production as a function of energy using a time-of-flight mass spectrometer. Energies and line widths for the v = 14–17 levels of the D1Πu+ state of H2 are reported and compared to experimental data obtained by using VUV synchrotron light excitation (Dickenson et al. 2010 J. Chem. Phys. 133 144317) and fully ab initio non-adiabatic calculations of D1Πu+ state energies and line widths (Glass-Maujean et al. 2012 Phys. Rev. A 86 052507). Several high vibrational levels of the B\u27\u27B-bar 1Σu+ state were also observed in this region. Term energies and rotational constants for the v = 67–69 vibrational levels are reported and compared to highly accurate ro-vibrational energy level predictions from fully ab initio non-adiabatic calculations of the first six 1Σu+ levels of H2 (Wolniewicz et al 2006 J. Mol. Spectrosc. 238 118). While additional observed transitions can be assigned to other states, several unassigned features in the spectra highlight the need for a fully integrated theoretical treatment of dissociation and ionization to understand the complex pattern of highly vibrationally excited states expected in this region

Double resonance spectroscopy of the D1Πu+ and B\u27\u27B-bar 1Σu+ states near the third dissociation threshold of H2

Double-resonance laser spectroscopy via the E, F 1Σg+, v\u27 = 6, J\u27 state was used to probe the energy region below the third dissociation limit of molecular hydrogen. Resonantly enhanced multi-photon ionization spectra were recorded by detecting ion production as a function of energy using a time-of-flight mass spectrometer. Energies and line widths for the v = 14–17 levels of the D1Πu+ state of H2 are reported and compared to experimental data obtained by using VUV synchrotron light excitation (Dickenson et al. 2010 J. Chem. Phys. 133 144317) and fully ab initio non-adiabatic calculations of D1Πu+ state energies and line widths (Glass-Maujean et al. 2012 Phys. Rev. A 86 052507). Several high vibrational levels of the B\u27\u27B-bar 1Σu+ state were also observed in this region. Term energies and rotational constants for the v = 67–69 vibrational levels are reported and compared to highly accurate ro-vibrational energy level predictions from fully ab initio non-adiabatic calculations of the first six 1Σu+ levels of H2 (Wolniewicz et al 2006 J. Mol. Spectrosc. 238 118). While additional observed transitions can be assigned to other states, several unassigned features in the spectra highlight the need for a fully integrated theoretical treatment of dissociation and ionization to understand the complex pattern of highly vibrationally excited states expected in this region

Photoelectron angular distributions from rotationally resolved autoionizing states of N2

The single-photon, photoelectron-photoion coincidence spectrum of N2 has been recorded at high (~1.5 cm–1 ) resolution in the region between the N2+ X 2Σg+, v+ = 0 and 1 ionization thresholds by using a double-imaging spectrometer and intense vacuum-ultraviolet light from the Synchrotron SOLEIL. This approach provides the relative photoionization cross section, the photoelectron energy distribution, and the photoelectron angular distribution as a function of photon energy. The region of interest contains autoionizing valence states, vibrationally autoionizing Rydberg states converging to vibrationally excited levels of the N2+ X 2Σg+ ground state, and electronically autoionizing states converging to the N2+ A 2Π and B 2Σu+ states. The wavelength resolution is sufficient to resolve rotational structure in the autoionizing states, but the electron energy resolution is insufficient to resolve rotational structure in the photoion spectrum. A simplified approach based on multichannel quantum defect theory is used to predict the photoelectron angular distribution parameters, β, and the results are in reasonably good agreement with experiment

Photoelectron angular distributions from rotationally resolved autoionizing states of N2

The single-photon, photoelectron-photoion coincidence spectrum of N2 has been recorded at high (~1.5 cm–1 ) resolution in the region between the N2+ X 2Σg+, v+ = 0 and 1 ionization thresholds by using a double-imaging spectrometer and intense vacuum-ultraviolet light from the Synchrotron SOLEIL. This approach provides the relative photoionization cross section, the photoelectron energy distribution, and the photoelectron angular distribution as a function of photon energy. The region of interest contains autoionizing valence states, vibrationally autoionizing Rydberg states converging to vibrationally excited levels of the N2+ X 2Σg+ ground state, and electronically autoionizing states converging to the N2+ A 2Π and B 2Σu+ states. The wavelength resolution is sufficient to resolve rotational structure in the autoionizing states, but the electron energy resolution is insufficient to resolve rotational structure in the photoion spectrum. A simplified approach based on multichannel quantum defect theory is used to predict the photoelectron angular distribution parameters, β, and the results are in reasonably good agreement with experiment

Facial mimcry and emotion consistency : Influences of memory and context.

This study investigates whether mimicry of facial emotions is a stable response or can instead be modulated and influenced by memory of the context in which the emotion was initially observed, and therefore the meaning of the expression. The study manipulated emotion consistency implicitly, where a face expressing smiles or frowns was irrelevant and to be ignored while participants categorised target scenes. Some face identities always expressed emotions consistent with the scene (e.g., smiling with a positive scene), whilst others were always inconsistent (e.g., frowning with a positive scene). During this implicit learning of face identity and emotion consistency there was evidence for encoding of face-scene emotion consistency, with slower RTs, a reduction in trust, and inhibited facial EMG for faces expressing incompatible emotions. However, in a later task where the faces were subsequently viewed expressing emotions with no additional context, there was no evidence for retrieval of prior emotion consistency, as mimicry of emotion was similar for consistent and inconsistent individuals. We conclude that facial mimicry can be influenced by current emotion context, but there is little evidence of learning, as subsequent mimicry of emotionally consistent and inconsistent faces is similar