Pygmy Dipole Strength in Exotic Nuclei and the Equation of State

Journal Article · Wed Aug 26 04:00:00 EDT 2009 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3232065· OSTI ID:21344570

Klimkiewicz, A; Adrich, P ^[1]; Uniwersytet Jagiellonski, Krakow ^[2]; Paar, N; Vretenar, D ^[3]; Fallot, M; Boretzky, K; Aksouh, F; Chatillon, A; Pramanik, U Datta; Emling, H; Ershova, O; Geissel, H; Gorska, M; Heil, M; Hellstroem, M; Jones, K L; Kurz, N; Litvinov, Y; Mahata, K ; Simon, H ^[1]

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1. GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany)
2. Poland
3. University of Zagreb (Croatia)

A concentration of dipole strength at energies below the giant dipole resonance was observed in neutron-rich nuclei around {sup 132}Sn in an experiment using the FRS-LAND setup. This so-called 'pygmy' dipole strength can be related to the parameters of the symmetry energy and to the neutron skin thickness on the grounds of a relativistic quasiparticle random-phase approximation. Using this ansatz and the experimental findings for {sup 130}Sn and {sup 132}Sn, we derive a value of the symmetry energy pressure of p-bar{sub 0} = 2.2+-0.5 MeV/fm{sup 3}. Neutron skin thicknesses of R{sub n}-R{sub p} 0.23+-0.03 fm and 0.24+-0.03 fm for {sup 130}Sn and {sup 132}Sn, respectively, have been determined. Preliminary results on {sup 68}Ni from a similar experiment using an improved setup indicate an enhanced cross section at low energies, while the results for {sup 58}Ni are in accordance with results from photoabsorption measurements.

• OSTI ID: 21344570
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 1165; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANTIBARYONS
ANTIMATTER
ANTINUCLEI
ANTINUCLEONS
ANTIPARTICLES
ANTIPROTONS
APPROXIMATIONS
BARYONS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CALCULATION METHODS
CROSS SECTIONS
DIPOLES
ELEMENTARY PARTICLES
ENERGY RANGE
EQUATIONS
EQUATIONS OF STATE
EVEN-EVEN NUCLEI
FERMIONS
FUNCTIONS
GIANT RESONANCE
HADRONS
INTERMEDIATE MASS NUCLEI
ISOTOPES
MATHEMATICAL MODELS
MATTER
MEV RANGE
MINUTES LIVING RADIOISOTOPES
MULTIPOLES
NEUTRON-RICH ISOTOPES
NEUTRONS
NICKEL 58
NICKEL 68
NICKEL ISOTOPES
NUCLEAR MODELS
NUCLEAR STRUCTURE
NUCLEI
NUCLEONS
ORGANS
PROTONS
RADIOISOTOPES
RANDOM PHASE APPROXIMATION
RELATIVISTIC RANGE
RESONANCE
SECONDS LIVING RADIOISOTOPES
SHELL MODELS
SKIN
STABLE ISOTOPES
STRENGTH FUNCTIONS
TIN 130
TIN 132
TIN ISOTOPES