English
Related papers

Related papers: Basis truncation, statistical errors, and systemat…

200 papers

The Random Phase and Amplitude Formalism (RPA) has significantly extended the scope of weak turbulence studies. Because RPA does not assume any proximity to the Gaussianity in the wavenumber space, it can predict, for example, how the…

Chaotic Dynamics · Physics 2014-01-15 Mitsuhiro Tanaka , Naoto Yokoyama

We use a continued fraction approximation to calculate the RPA response function of nuclear matter. The convergence of the approximation is assessed by comparing with the numerically exact response function obtained with a typical effective…

Nuclear Theory · Physics 2008-11-26 Jérôme Margueron , J. Navarro , Nguyen Van Giai , P. Schuck

Working within an exactly solvable 3 level model, we discuss am extension of the Random Phase Approximation (RPA) based on a boson formalism. A boson Hamiltonian is defined via a mapping procedure and its expansion truncated at four-boson…

Nuclear Theory · Physics 2016-09-08 F. Catara , M. Grasso , M. Sambataro

We have calculated the strength distributions of the dipole response in spherical nuclei, ranging all over the periodic table. The calculations were performed within two microscopic models: the discretized quasiparticle random phase…

Nuclear Theory · Physics 2011-05-05 I. Daoutidis , P. Ring

The random phase approximation (RPA) has received a considerable interest in the field of modeling systems where noncovalent interactions are important. Its advantages over widely used density functional theory (DFT) approximations are the…

Chemical Physics · Physics 2019-12-04 Marcin Modrzejewski , Sirous Yourdkhani , Jiri Klimes

The radial basis function (RBF) approach is applied in predicting nuclear masses for 8 widely used nuclear mass models, ranging from macroscopic-microscopic to microscopic types. A significantly improved accuracy in computing nuclear masses…

Nuclear Theory · Physics 2013-09-03 Z. M. Niu , Z. L. Zhu , Y. F. Niu , B. H. Sun , T. H. Heng , J. Y. Guo

We investigate collective multipole excitations for closed shell nuclei from 16O to 208Pb using correlated realistic nucleon -nucleon interactions in the framework of the random phase approximation (RPA). The dominant short-range central…

Nuclear Theory · Physics 2009-11-11 N. Paar , P. Papakonstantinou , H. Hergert , R. Roth

A comparative study of the nuclear Gamow-Teller response (GTR) within conceptually different state-of-the-art approaches is presented. Three nuclear microscopic models are considered: (i) the recently developed charge-exchange relativistic…

Nuclear Theory · Physics 2015-06-18 E. Litvinova , B. A. Brown , D. -L. Fang , T. Marketin , R. G. T. Zegers

The self-consistent Relativistic Quasiparticle Random Phase Approximation (RQRPA) is extended by the quasiparticle-phonon coupling (QPC) model using the Quasiparticle Time Blocking Approximation (QTBA). The method is formulated in terms of…

Nuclear Theory · Physics 2008-11-26 E. Litvinova , P. Ring , V. Tselyaev

New results for electric dipole strength in the chain of even-even Calcium isotopes with the mass numbers A = 40 - 54 are presented. Starting from the covariant Lagrangian of Quantum Hadrodynamics, spectra of collective vibrations (phonons)…

Nuclear Theory · Physics 2016-11-03 Irina A. Egorova , Elena Litvinova

The effects of ground-state correlations on the damping of isovector giant dipole resonances in $LS$ closed shell nuclei $^{16}$O and $^{40}$Ca are studied using extended random-phase-approximation (RPA) approaches derived from the…

Nuclear Theory · Physics 2022-02-24 Mitsuru Tohyama

In the paper the non-linear generalization of the time blocking approximation (TBA) is presented. The TBA is one of the versions of the extended random-phase approximation (RPA) developed within the Green-function method and the…

Nuclear Theory · Physics 2018-04-18 V. Tselyaev , N. Lyutorovich , J. Speth , P. -G. Reinhard

Understanding physical mechanisms relies on the accurate determination of fundamental constants, although inherent limitations in experimental techniques introduce uncertainties into these measurements. This paper explores the uncertainties…

General Relativity and Quantum Cosmology · Physics 2024-07-11 Surajit Kalita

We have developed a fully consistent framework for calculations in the Quasiparticle Random Phase Approximation (QRPA) with $NN$ interactions from the Similarity Renormalization Group (SRG) and other unitary transformations of realistic…

Nuclear Theory · Physics 2011-07-04 H. Hergert , P. Papakonstantinou , R. Roth

A microscopic formalism is developed that includes the coupling to two particle-hole phonons in the particle-hole propagator by extending the dressed random phase approximation (DRPA) equation for a finite system. The resulting formalism is…

Nuclear Theory · Physics 2016-09-08 C. Barbieri , W. H. Dickhoff

Response functions in nuclear matter at finite temperature are considered beyond the usual Hartree-Fock (HF) plus Random Phase Approximation (RPA) scheme. The contributions due to the propagator for the dressed nucleons and the…

Nuclear Theory · Physics 2009-11-10 P. Bozek , J. Margueron , H. Muther

In the present contribution, we discuss the behavior of Skyrme forces when they are employed to study both neutron stars and giant resonance states in 208Pb within the fully self-consistent Random Phase Approximation (RPA). We point out…

Nuclear Theory · Physics 2009-06-12 G. Colo'

The question of nuclear response functions in a homogeneous medium is examined. A general method for calculating response functions in the random phase approximation (RPA) with exchange is presented. The method is applicable for…

Nuclear Theory · Physics 2007-05-23 J. Margueron , Nguyen Van Giai , J. Navarro

While the no-core shell model is a state-of-the-art microscopic approach to low-energy nuclear structure, its intense computational requirements lead us to consider time-honored approximations such as the Hartree-Fock (HF) approximation and…

Nuclear Theory · Physics 2007-05-23 Calvin W. Johnson , Ionel Stetcu

A role of \beta-delayed neutron emission and fission in r-process nucleosynthesis attracts a high interest. Although the number of study on them covering r-process nuclei is increasing recently, uncertainties of \beta-delayed neutron and…

Nuclear Theory · Physics 2021-02-24 Futoshi Minato , Tomislav Marketin , Nils Paar