Self-consistent description of nuclear compressional modes

Piekarewicz, J.

doi:10.1103/physrevc.64.024307

Cited by 77 publications

(111 citation statements)

References 39 publications

Supporting

Mentioning

106

Contrasting

Order By: Relevance

“…The formalism underlying the calculation of the relativistic mean-field ground state and the corresponding linear response has been reviewed extensively in earlier publications [16,41,42]. Although a full review of the formalism is no longer necessary, we nevertheless highlight those points that are of relevance to the present work, specifically the role of the continuum on the distribution of low-energy isoscalar monopole strength.…”

Section: A Isoscalar Monopole Responsementioning

confidence: 98%

Nuclear breathing mode in neutron-rich nickel isotopes: Sensitivity to the symmetry energy and the role of the continuum

Piekarewicz

2015

Phys. Rev. C

Self Cite

View full text Add to dashboard Cite

Background: In this new era of radioactive beam facilities, the discovery of novel modes of excitation in nuclei far away from stability represents an area of intense research activity. In addition, some of these modes of excitation, particularly the isoscalar monopole and isovector dipole resonances, appear to be sensitive to the uncertain density dependence of the symmetry energy.Purpose: It is the main goal of this paper to examine the emergence, evolution, and nature of both the soft and giant isoscalar monopole modes as a function of neutron excess in three unstable Nickel isotopes: 56 Ni, 68 Ni, and 78 Ni.Methods: The distribution of isoscalar monopole strength is computed in a relativistic random-phase approximation using several accurately calibrated effective interactions. In particular, a non-spectral Green's function approach is adopted that allows for an exact treatment of the continuum without any reliance on discretization. The discretization of the continuum is neither required nor admitted.Results: In the case of 56 Ni, the lack of low-energy strength results in a direct correlation between the centroid energy of the giant monopole resonance and the incompressibility coefficient of symmetric nuclear matter. In contrast, the large neutron excess in both 68 Ni and 78 Ni generates a significant, yet relatively featureless, amount of low-energy strength that is driven by transitions into the continuum. Moreover, the evolution of monopole strength with neutron excess displays sensitivity to the density dependence of the symmetry energy.Conclusions: It is suggested that future measurements of the distribution of isoscalar monopole strength at radioactive beam facilities using a very long chain of both stable and unstable isotopes could place important constraints on the equation of state of neutron-rich matter and ultimately on the properties of neutron stars. However, given the nature of the low-energy monopole excitations, a proper treatment of the continuum is absolutely essential.

show abstract

Section: A Isoscalar Monopole Responsementioning

confidence: 98%

Nuclear breathing mode in neutron-rich nickel isotopes: Sensitivity to the symmetry energy and the role of the continuum

Piekarewicz

2015

Phys. Rev. C

Self Cite

View full text Add to dashboard Cite

show abstract

“…The macroscopic-microscopic approach has enjoyed its greatest success in the work of Möller and collaborators [1,2,3], and Duflo and Zuker [4,5,6]. Although refinements to the mass formula have been made to meet new and increasing challenges, the structure of this 75 year-old formula remains practically unchanged. We now consider the thermodynamic limit of the liquiddrop formula in which both the number of nucleons and the volume are taken to infinity, but their ratio remains fixed at the saturation density.…”

Section: Introductionmentioning

confidence: 99%

Symmetry energy constraints from giant resonances: A relativistic mean-field theory overview

Piekarewicz

2014

Eur. Phys. J. A

Self Cite

View full text Add to dashboard Cite

Abstract. Giant resonances encapsulate the dynamic response of the nuclear ground state to external perturbations. As such, they offer a unique view of the nucleus that is often not accessible otherwise. Although interesting in their own right, giant resonances are also enormously valuable in providing stringent constraints on the equation of state of asymmetric matter. We this view in mind, we focus on two modes of excitation that are essential in reaching this goal: the isoscalar giant monopole resonance (GMR) and the isovector giant dipole resonance (GDR). GMR energies in heavy nuclei are sensitive to the symmetry energy because they probe the incompressibility of neutron-rich matter. Unfortunately, access to the symmetry energy is hindered by the relatively low neutron-proton asymmetry of stable nuclei. Thus, the measurement of GMR energies in exotic nuclei is strongly encouraged. In the case of the GDR, we find the electric dipole polarizability of paramount importance. Indeed, the electric dipole polarizability appears as one of two laboratory observables-with the neutron-skin thickness being the other-that are highly sensitive to the density dependence of the symmetry energy. Finally, we identify the softness of skin and the nature of the pygmy resonance as important unsolved problems in nuclear structure.

show abstract

“…Theoretical interpretations of the PDR have been attempted utilizing a variety of sometimes conflicting models ranging from hydrodynamical descriptions [2,3], neutron excess surface density oscillations [4][5][6], fluid-dynamical approaches [7][8][9] to local isospin breaking in heavy nuclei by clustering [10]. Recent work has focused on microscopic nonrelativistic [11,12] and relativistic [13][14][15] random phase approximation (RPA) calculations which predict a strong isoscalar E1 mode well below the GDR with toroidal current distributions [16].…”

mentioning

confidence: 99%

Nature of Low-Energy Dipole Strength in Nuclei: The Case of a Resonance at Particle Threshold inP208b

et al. 2002

View full text Add to dashboard Cite

A high-resolution (gamma,gamma') study of the electric dipole response in 208Pb at the S-DALINAC reveals a resonance structure centered around the neutron emission threshold. Microscopic quasiparticle phonon model calculations in realistic model spaces including the coupling to complex configurations are able to describe the data in great detail. The resonance is shown to result from surface density oscillations of the neutron skin relative to an approximately isospin-saturated core. It also forms an integral part of a toroidal E1 mode representing an example of vortex collective motion in nuclei.

show abstract

Self-consistent description of nuclear compressional modes

Cited by 77 publications

References 39 publications

Nuclear breathing mode in neutron-rich nickel isotopes: Sensitivity to the symmetry energy and the role of the continuum

Nuclear breathing mode in neutron-rich nickel isotopes: Sensitivity to the symmetry energy and the role of the continuum

Symmetry energy constraints from giant resonances: A relativistic mean-field theory overview

Nature of Low-Energy Dipole Strength in Nuclei: The Case of a Resonance at Particle Threshold inP208b

Contact Info

Product

Resources

About