Observation of diffractive orbits in the spectrum of excited NO in a magnetic field

We investigate the experimental spectra of excited NO molecules in the diamagnetic regime and develop a quantitative semiclassical framework to account for the results. We show the dynamics can be interpreted in terms of classical orbits provided that in addition to the geometric orbits, diffractive effects are appropriately taken into account. We also show how individual orbits can be extracted from the experimental signal and use this procedure to reveal the first experimental manifestation of inelastic diffractive orbits.Comment: 4 fig

Contribution of forbidden orbits in the photoabsorption spectra of atoms and molecules in a magnetic field

In a previous work [Phys. Rev. A \textbf{66}, 0134XX (2002)] we noted a partial disagreement between quantum R-matrix and semiclassical calculations of photoabsorption spectra of molecules in a magnetic field. We show this disagreement is due to a non-vanishing contribution of processes which are forbidden according to the usual semiclassical formalism. Formulas to include these processes are obtained by using a refined stationary phase approximation. The resulting higher order in $\hbar$ contributions also account for previously unexplained ``recurrences without closed-orbits''. Quantum and semiclassical photoabsorption spectra for Rydberg atoms and molecules in a magnetic field are calculated and compared to assess the validity of the first-order forbidden orbit contributions.Comment: 12 pages, 6 figure

Molecules in external fields: a semiclassical analysis

We undertake a semiclassical analysis of the spectral properties (modulations of photoabsorption spectra, energy level statistics) of a simple Rydberg molecule in static fields within the framework of Closed-Orbit/Periodic-Orbit theories. We conclude that in addition to the usual classically allowed orbits one must consider classically forbidden diffractive paths. Further, the molecule brings in a new type of 'inelastic' diffractive trajectory, different from the usual 'elastic' diffractive orbits encountered in previous studies of atomic and analogous systems such as billiards with point-scatterers. The relative importance of inelastic versus elastic diffraction is quantified by merging the usual Closed Orbit theory framework with molecular quantum defect theory.Comment: 4 pages, 3 figure

Statistical Properties of Fano Resonances in Atomic and Molecular Photoabsorption

Statistical properties of Fano resonances occurring in photoabsorption to highly excited atomic or molecular states are derived. The situation with one open and one closed channel is analyzed when the classical motion of the excited complex in the closed channel is chaotic. The closed channel subspace is modeled by random matrix theory. The probability distribution of the Fano parameter is derived both for the case of time reversal symmetry (TRS) and broken time reversal symmetry. For the TRS case the area distribution under a resonance profile relevant for low resolution experiments is discussed in detail.Comment: 4 pages, 4 figure

Photoabsorption spectra of the diamagnetic hydrogen atom in the transition regime to chaos: Closed orbit theory with bifurcating orbits

With increasing energy the diamagnetic hydrogen atom undergoes a transition from regular to chaotic classical dynamics, and the closed orbits pass through various cascades of bifurcations. Closed orbit theory allows for the semiclassical calculation of photoabsorption spectra of the diamagnetic hydrogen atom. However, at the bifurcations the closed orbit contributions diverge. The singularities can be removed with the help of uniform semiclassical approximations which are constructed over a wide energy range for different types of codimension one and two catastrophes. Using the uniform approximations and applying the high-resolution harmonic inversion method we calculate fully resolved semiclassical photoabsorption spectra, i.e., individual eigenenergies and transition matrix elements at laboratory magnetic field strengths, and compare them with the results of exact quantum calculations.Comment: 26 pages, 9 figures, submitted to J. Phys.

The salience of children increases adult prosocial values

Organizations often put children front and center in campaigns to elicit interest and support for prosocial causes. Such initiatives raise a key theoretical and applied question that has yet to be addressed directly: Does the salience of children increase prosocial motivation and behavior in adults? We present findings aggregated across eight experiments involving 2,054 adult participants: Prosocial values became more important after completing tasks that made children salient compared to tasks that made adults (or a mundane event) salient or compared to a no-task baseline. An additional field study showed that adults were more likely to donate money to a child-unrelated cause when children were more salient on a shopping street. The findings suggest broad, reliable interconnections between human mental representations of children and prosocial motives, as the child salience effect was not moderated by participants’ gender, age, attitudes, or contact with children

Attitudes toward children : distinguishing affection and stress

This project was supported by funding from the Economic and Social Research Council (ESRC) under grant agreement ES/P002463/1.Background Adults' views and behaviors toward children can vary from being supportive to shockingly abusive, and there are significant unanswered questions about the psychological factors underpinning this variability. Objective The present research examined the content of adults' attitudes toward children to address these questions. Method Ten studies (N?=?4702) identified the factor structure of adults' descriptions of babies, toddlers, and school-age children and examined how the resulting factors related to a range of external variables. Results Two factors emerged?affection toward children and stress elicited by them?and this factor structure was invariant across the United Kingdom, the United States, and South Africa. Affection uniquely captures emotional approach tendencies, concern for others, and broad positivity in evaluations, experiences, motivations, and donation behavior. Stress relates to emotional instability, emotional avoidance, and concern about disruptions to a self-oriented, structured life. The factors also predict distinct experiences in a challenging situation?home-parenting during COVID-19 lockdown?with affection explaining greater enjoyment and stress explaining greater perceived difficulty. Affection further predicts mentally visualizing children as pleasant and confident, whereas stress predicts mentally visualizing children as less innocent. Conclusions These findings offer fundamental new insights about social cognitive processes in adults that impact adult?child relationships and children's well-being.Publisher PDFPeer reviewe

the State of Utah v. Walter Preston Boggess, Jr. : Brief of Respondent

An Appeal from a Judgment of the District Court of the Fourth Judicial District, The Honorable J, Robert Bullock, District Court Judg