Systematics of the double giant dipole resonances in nuclei

Journal Article · Wed Jan 01 04:00:00 EST 1992 · Physical Review, C (Nuclear Physics); (United States)

DOI:https://doi.org/10.1103/PhysRevC.45.197· OSTI ID:5134805

Bar-Touv, J; Mordechai, S ^[1]

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1. Department of Physics, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva 84105 (Israel)

A generalization of the continuum open-shell {ital r}-space linear response random-phase approximation method to finite temperatures (i.e., TDRPA method) is applied in a study of the systematics of the electric double giant dipole resonance (DGDR) in magic and open-shell nuclei covering a wide range of nuclear masses. Viewing the DGDR as a single-phonon vibration in a hot nucleus, whose temperature corresponds to the centroid energy of the ground-state (zero-temperature) GDR, the TDRPA equation has been solved for the eleven nuclei whose DGDR state has recently been investigated in pion double-charge-exchange (DCX) experiments. The expected general features of a collective vibration in hot nuclei, particularly the broadening and the downshift of the GDR excitation energy due to increase in temperature, were found to be small, yet quite distinguishable. Except for the lighter nuclei, a reliable estimate for the DGDR energy would be {ital E}{sup DGDR}{approx}2{ital E}{sup GDR} and the estimate for its width would be {Gamma}{sup DGDR}{approx} {radical}2 {Gamma}{sup GDR}. However, the changes in the integrated cross sections of the DGDR due to finite temperature are found to be much more significant. An exact {ital A}{sup {minus}1/6} power law for the DGDR energy is suggested by the TDRPA solutions. A gratifying agreement between the TDRPA predictions and experiment has been established for the {ital Q} values of the relevant pion DCX reactions after taking into account the proper Coulomb and symmetry energy corrections.

• OSTI ID: 5134805
• Journal Information: Physical Review, C (Nuclear Physics); (United States), Journal Name: Physical Review, C (Nuclear Physics); (United States) Vol. 45:1; ISSN 0556-2813; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

663110* -- General & Average Properties of Nuclei & Nuclear Energy Levels-- (1992-)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
CHARGE-EXCHANGE REACTIONS
CHARGED-PARTICLE REACTIONS
COLLECTIVE EXCITATIONS
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EXCITATION
FERMI RESONANCE
GAMOW-TELLER RULES
GIANT RESONANCE
HADRON REACTIONS
HIGH SPIN STATES
MATHEMATICAL MODELS
MESON REACTIONS
NUCLEAR MODELS
NUCLEAR REACTIONS
NUCLEI
PION REACTIONS
QUASIPARTICLE-PHONON MODEL
RANDOM PHASE APPROXIMATION
RESONANCE
TEMPERATURE EFFECTS