Time scales of multiple giant dipole resonance excitation and decay
نویسندگان
چکیده
منابع مشابه
Evolution of the Giant Dipole Resonance Properties with Excitation Energy
The studies of the evolution of the hot Giant Dipole Resonance (GDR) properties as a function of excitation energy are reviewed. The discussion will mainly focus on the A ∼ 100 − 120 mass region where a large amount of data concerning the width and the strength evolution with excitation energy are available. Models proposed to interpret the main features and trends of the experimental results w...
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High-energy y rays have been measured in coincidence with heavy fragments in deeply inelastic reactions of ' 6xe+ Ti at 18.5 MeV/nucleon. The giant dipole resonance (GDR) strength function is deduced from an analysis of the photon spectra within the statistical model. The GDR width I is studied as a function of the fragment excitation energy E*. A saturation at about I =10 MeV is observed for E...
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The value of an isomeric ratio (IR) in N=81 isotones (137Ba, 139Ce, 141Nd and 143Sm) is studied by means of the (γ, n) reaction. This quantity measures a probability to populate the isomeric state in respect to the ground state population. In (γ, n) reactions, the giant dipole resonance (GDR) is excited and after its decay by a neutron emission, the nucleus has an excitation energy of a few MeV...
متن کاملMultiple giant resonances in nuclei: their excitation and decay
The excitation of multiphonon giant resonances with heavy ions is discussed. The conventional theory, based on the use of the virtual photon number method in conjunction with the harmonic model is presented and its shortcomings are discussed. The recently developed model that invoke the Brink-Axel mechanism as an important contribution to the cross-section is discussed and compared to the conve...
متن کاملCoulomb Excitation of Double Giant Dipole Resonances
We implement the Brink–Axel hypothesis for the excitation of the double giant dipole resonance (DGDR): The background states which couple to the one–phonon giant dipole resonance are themselves capable of dipole absorption. These states (and the ones which couple to the two–phonon resonance) are described in terms of the Gaussian Orthogonal Ensemble of random matrices. We use second–order time–...
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ژورنال
عنوان ژورنال: Physical Review C
سال: 1999
ISSN: 0556-2813,1089-490X
DOI: 10.1103/physrevc.59.r2343