Pygmy dipole resonance in nuclei

Journal Article · Sat Aug 15 00:00:00 EDT 2009 · Physics of Atomic Nuclei

DOI:https://doi.org/10.1134/S1063778809080080· OSTI ID:21449007

Avdeenkov, A V ^[1]; Kamerdzhiev, S P ^[2]

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1. Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation)
2. Institute of Physics and Power Engineering (Russian Federation)

A brief survey of the state of the modern microscopic theory of the so-called pygmy dipole resonance in nuclei is given-in particular, some unresolved problems are listed. It is emphasized that, in order to explain the pygmy dipole resonance, it is necessary but not sufficient to take into account the coupling of single-particle degrees of freedom to photon degrees of freedom. The results of the calculations performed for the first time for the isovector pygmy dipole resonance and the isovector electric giant dipole resonance in {sup 124}Sn within a self-consistent approach involving, in addition to the standard quasiparticle random-phase approximation, a single-particle continuum and quasiparticle-phonon coupling of single-particle degrees of freedom to phonon degrees of freedom are presented. The results are found to be in satisfactory agreement with experimental data. The calculation of the isoscalar strength function in the energy region of the pygmy dipole resonance revealed that the nuclear-structure mechanism does not provide the isoscalar-strength suppression observed at energies in excess of 7 MeV in ({alpha}, {alpha}'{gamma}) reactions; therefore, this suppression may stem from the reaction mechanism.

• OSTI ID: 21449007
• Journal Information: Physics of Atomic Nuclei, Vol. 72, Issue 8; Other Information: DOI: 10.1134/S1063778809080080; Copyright (c) 2009 Pleiades Publishing, Ltd.; ISSN 1063-7788
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
COUPLING
DEGREES OF FREEDOM
DIPOLES
ISOVECTORS
NUCLEAR REACTION KINETICS
NUCLEAR STRUCTURE
PHONONS
RANDOM PHASE APPROXIMATION
RESONANCE
STRENGTH FUNCTIONS
TIN 124
APPROXIMATIONS
CALCULATION METHODS
EVEN-EVEN NUCLEI
FUNCTIONS
INTERMEDIATE MASS NUCLEI
ISOTOPES
KINETICS
MULTIPOLES
NUCLEI
QUASI PARTICLES
REACTION KINETICS
STABLE ISOTOPES
TENSORS
TIN ISOTOPES
VECTORS