Isospin Character of the Pygmy Dipole Resonance in {sup 124}Sn

Journal Article · Fri Nov 19 04:00:00 EST 2010 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.105.212503· OSTI ID:21541723

Endres, J; Zilges, A ^[1]; Litvinova, E ^[2]; Savran, D; Pietralla, N; Ponomarev, V Yu; Sonnabend, K ^[3]; Butler, P A; Herzberg, R -D; Scheck, M ^[4]; Harakeh, M N ^[2]; Harissopulos, S; Lagoyannis, A ^[5]; Kruecken, R; Ring, P ^[6]; Popescu, L ^[7]; Stoica, V I; Woertche, H J ^[7]

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1. Institut fuer Kernphysik, Universitaet zu Koeln, Zuelpicher Strasse 77, D-50937 Koeln (Germany)
2. GSI Helmholtzzentrum fuer Schwerionenforschung, D-64291 Darmstadt (Germany)
3. Institut fuer Kernphysik, TU Darmstadt, D-64289 Darmstadt (Germany)
4. Oliver Lodge Laboratory, University of Liverpool, L69 7ZE (United Kingdom)
5. Institute of Nuclear Physics, N.C.S.R. Demokritos Athens, GR-15310 Athens (Greece)
6. Physik Department, TU Muenchen, D-85748 Garching (Germany)
7. Kernfysisch Versneller Instituut, University of Groningen, 9747 AA Groningen (Netherlands)

The pygmy dipole resonance has been studied in the proton-magic nucleus {sup 124}Sn with the ({alpha}, {alpha}{sup '{gamma}}) coincidence method at E{sub {alpha}=}136 MeV. The comparison with results of photon-scattering experiments reveals a splitting into two components with different structure: one group of states which is excited in ({alpha}, {alpha}{sup '{gamma}}) as well as in ({gamma}, {gamma}{sup '}) reactions and a group of states at higher energies which is only excited in ({gamma}, {gamma}{sup '}) reactions. Calculations with the self-consistent relativistic quasiparticle time-blocking approximation and the quasiparticle phonon model are in qualitative agreement with the experimental results and predict a low-lying isoscalar component dominated by neutron-skin oscillations and a higher-lying more isovector component on the tail of the giant dipole resonance.

• OSTI ID: 21541723
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 21 Vol. 105; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
BARYONS
BOSONS
COINCIDENCE METHODS
COMPARATIVE EVALUATIONS
COUNTING TECHNIQUES
DIPOLES
ELEMENTARY PARTICLES
ENERGY RANGE
EVALUATION
EVEN-EVEN NUCLEI
FERMIONS
HADRONS
INTERMEDIATE MASS NUCLEI
ISOSPIN
ISOTOPES
ISOVECTORS
MAGIC NUCLEI
MASSLESS PARTICLES
MATHEMATICAL MODELS
MEV RANGE
MULTIPOLES
NEUTRONS
NUCLEAR MODELS
NUCLEI
NUCLEONS
OSCILLATIONS
PARTICLE PROPERTIES
PHOTONS
PROTONS
QUASIPARTICLE-PHONON MODEL
RELATIVISTIC RANGE
RESONANCE
SCATTERING
SKIN EFFECT
STABLE ISOTOPES
TENSORS
TIN 124
TIN ISOTOPES
VECTORS