Center for Molecular Modeling - W.H. Dickhoff

Saturation of Nuclear Matter and Short-Range Correlations

wim — Fri, 30 Sep 2011 11:50:05 +0000

Y. Dewulf, W.H. Dickhoff, D. Van Neck, E.R. Stoddard, M. Waroquier

Physical Review Letters

90 (15), 152501

2003

Abstract

A fully self-consistent treatment of short-range correlations in nuclear matter is presented. Different implementations of the determination of the nucleon spectral functions for different interactions are shown to be consistent with each other. The resulting saturation densities are closer to the empirical result when compared with (continuous choice) Brueckner-Hartree-Fock values. Arguments for the dominance of short-range correlations in determining the nuclear matter saturation density are presented. A further survey of the role of long-range correlations suggests that the inclusion of pionic contributions to ring diagrams in nuclear matter leads to higher saturation densities than empirically observed. A possible resolution of the nuclear matter saturation problem is suggested.

DOI

http://dx.doi.org/10.1103/PhysRevLett.90.152501

Private attachment

03 phys rev lett 90(15)152501 dewulf.pdf

Nonlocal extension of the dispersive optical model to describe data below the Fermi energy

wim — Tue, 13 Sep 2011 11:01:58 +0000

W.H. Dickhoff, D. Van Neck, S.J. Waldecker, R.J. Charity, L.G. Sobotka

Physical Review C

82, 054306

2010

Abstract

Present applications of the dispersive-optical-model analysis are restricted by the use of a local but energy-dependent version of the generalized Hartree-Fock potential. This restriction is lifted by the introduction of a corresponding nonlocal potential without explicit energy dependence. Such a strategy allows for a complete determination of the nucleon propagator below the Fermi energy with access to the expectation value of one-body operators (like the charge density), the one-body density matrix with associated natural orbits, and complete spectral functions for removal strength. The present formulation of the dispersive optical model (DOM) therefore allows the use of elastic electron-scattering data in determining its parameters. Application to 40Ca demonstrates that a fit to the charge radius leads to too much charge near the origin using the conventional assumptions of the functional form of the DOM. A corresponding incomplete description of high-momentum components is identified, suggesting that the DOM formulation must be extended in the future to accommodate such correlations properly. Unlike the local version, the present nonlocal DOM limits the location of the deeply bound hole states to energies that are consistent with (e,e′p) and (p,2p) data.

DOI

http://dx.doi.org/10.1103/PhysRevC.82.054306

Private attachment

10_phys.rev_.c_82_054306_dickhoff.pdf

Many-Body Theory Exposed! Propagator Description of Quantum Mechanics in Many-Body Systems

wim — Mon, 03 Oct 2011 13:44:33 +0000

W.H. Dickhoff, D. Van Neck

World Scientific Publishing Company

2006

ISBN

978-9812813794

Short content

This comprehensive textbook on the quantum mechanics of identical particles includes a wealth of valuable experimental data, in particular recent results from direct knockout reactions directly related to the single-particle propagator in many-body theory. The comparison with data is incorporated from the start, making the abstract concept of propagators vivid and accessible. Results of numerical calculations using propagators or Green's functions are also presented. The material has been thoroughly tested in the classroom and the introductory chapters provide a seamless connection with a one-year graduate course in quantum mechanics. While the majority of books on many-body theory deal with the subject from the viewpoint of condensed matter physics, this book emphasizes finite systems as well and should be of considerable interest to researchers in nuclear, atomic, and molecular physics. A unified treatment of many different many-body systems is presented using the approach of self-consistent Green's functions. The second edition contains an extensive presentation of finite temperature propagators and covers the technique to extract the self-energy from experimental data as developed in the dispersive optical model.
The coverage proceeds systematically from elementary concepts, such as second quantization and mean-field properties, to a more advanced but self-contained presentation of the physics of atoms, molecules, nuclei, nuclear and neutron matter, electron gas, quantum liquids, atomic Bose Einstein and fermion condensates, and pairing correlations in finite and infinite systems, including finite temperature.

Contents: Identical Particles; Second Quantization; Independent-Particle Model for Fermions in Finite Systems; Two-Particle States and Interactions; Noninteracting Bosons and Fermions; Propagators in One-Particle Quantum Mechanics; Single-Particle Propagator in the Many-Body System; Perturbation Expansion of the Single-Particle Propagator; Dyson Equation and Self-consistent Green's Functions; Mean-Field or Hartree Fock Approximation; Beyond the Mean-Field Approximation; Interacting Boson Systems; Excited States in Finite Systems; Excited States in Infinite Systems; Excited States in N Â± 2 Systems and In-Medium Scattering; Dynamical Treatment of the Self-energy in Infinite Systems; Dynamical Treatment of the Self-energy in Finite Systems; Bogoliubov Perturbation Expansion for the Bose Gas; Boson Perturbation Theory Applied to Physical Systems; In-Medium Interaction and Scattering of Dressed Particles; Conserving Approximations and Excited States; Pairing Phenomena; Elastic Scattering and the Self-Energy in Finite Systems; Finite Temperature Formalism and Applications. | 2nd edition, 2008.

http://www.amazon.com/Many-Body-Theory-Exposed-Propagator-Description/dp...