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## Full-Text Articles in Physics

Dramatic Nondipole Effects In Low-Energy Photoionization: Experimental And Theoretical Study Of Xe 5s, Oliver Hemmers, Renaud Guillemin, E. P. Kanter, B. Krassig, Dennis W. Lindle, S. H. Southworth, R. Wehlitz, J. Baker, A. C. Hudson, M. Lotrakul, D. Rolles, Wayne C. Stolte, I. Tran, A. Wolska, S. Yu, M. Ya Amusia, K. T. Cheng, L. V. Chernysheva, W. R. Johnson, S. T. Manson

#### Dramatic Nondipole Effects In Low-Energy Photoionization: Experimental And Theoretical Study Of Xe 5s, Oliver Hemmers, Renaud Guillemin, E. P. Kanter, B. Krassig, Dennis W. Lindle, S. H. Southworth, R. Wehlitz, J. Baker, A. C. Hudson, M. Lotrakul, D. Rolles, Wayne C. Stolte, I. Tran, A. Wolska, S. Yu, M. Ya Amusia, K. T. Cheng, L. V. Chernysheva, W. R. Johnson, S. T. Manson

*Environmental Studies Faculty Publications*

The Xe 5s nondipole photoelectron parameter γ is obtained experimentally and theoretically from threshold to ∼200 eV photon energy. Significant nondipole effects are seen even in the threshold region of this valence shell photoionization. In addition, contrary to previous understanding, clear evidence of interchannel coupling among quadrupole photoionization channels is found.

E1-E2 Interference In The Vuv Photoionization Of He, E. P. Kanter, B. Krassig, S. H. Southworth, Renaud Guillemin, Oliver Hemmers, Dennis W. Lindle, R. Wehlitz, M. Ya Amusia, L. V. Chernysheva, N. L. S. Martin

#### E1-E2 Interference In The Vuv Photoionization Of He, E. P. Kanter, B. Krassig, S. H. Southworth, Renaud Guillemin, Oliver Hemmers, Dennis W. Lindle, R. Wehlitz, M. Ya Amusia, L. V. Chernysheva, N. L. S. Martin

*Environmental Studies Faculty Publications*

We have measured the forward-backward asymmetry of photoelectron angular distributions produced in the vacuum ultraviolet photoionization of helium. This asymmetry, a consequence of the breakdown of the dipole approximation, measures the real part of the ratio of the quadrupole and dipole matrix elements. In the autoionization region, the strong energy dependence of the asymmetry permits an experimental separation of the ratio of those magnitudes from their phase difference. We experimentally determined the Fano parameters of the 2p^{2}^{1}D_{2} quadrupole resonance, and report improved values of the width Γ and line profile parameter q from those previously available ...

Theoretical Models Of Many-Quark Bound States , Richard Jeffrey Lloyd

#### Theoretical Models Of Many-Quark Bound States , Richard Jeffrey Lloyd

*Retrospective Theses and Dissertations*

The foundations of Many-Fermion Dynamics (MFD) are developed with special attention paid to a treatment of color and flavor degrees of freedom. From these ingredients a framework was developed to calculate the properties of many-fermion bound states. The quark implementation of MFD (MFDq) was extensively tested on the 2-body problem against the established nucleon implementation of MFD (MFDn). We were able to perform a limited set of self-consistency checks of MFDq in the 4-body problem to test a proper treatment of all computed matrix elements.;Finally, calculations are presented using MFDn to predict the properties of 4-body charmonium bound states ...

Statistical And Thermal Properties Of Mesoscopic Systems: Application To The Many-Nucleon System , Bassam A. Shehadeh

#### Statistical And Thermal Properties Of Mesoscopic Systems: Application To The Many-Nucleon System , Bassam A. Shehadeh

*Retrospective Theses and Dissertations*

The dissertation investigates the statistical and thermal properties of mesoscopic systems and applies it to the multi-nucleon systems. The investigation was carried out using four approaches starting from the simplest and progressing to the more sophisticated. The first approach develops and employs the three-dimensional simple harmonic oscillator (3D-SHO) quantum statistics to obtain the thermal properties of multi-particle systems. The recently discovered method that relates the single particle oscillator properties to the multi particle oscillator is applied. The approach is successful in predicting observables at temperatures beginning slightly above the ground state domain for nuclear systems. The 3D-SHO potential function is ...