The Temperature Dependence of the Width of the Giant Dipole Resonance
The Temperature Dependence of the Width of the Giant Dipole Resonance

Author:

Publisher:

Published: 1995

Total Pages: 8

ISBN-13:

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A systematic study of the full-width-at-half-maximum (FWHM) of the giant-dipole resonance (GDR) as a function of temperature for the nuclei 12°Sn and 2°8Pb confirms the overall theoretical picture of the GDR in hot nuclei; in particular, the role played by large-amplitude thermal fluctuations of the nuclear shape. This is confirmed by the good agreement between theory and experiment achieved over a range of temperatures from 1.25--32 MeV and by the differences in the behavior of the FWHM for 12°Sn and 2°8Pb, which can be attributed to the presence of strong shell corrections favoring spherical shapes in 2°8Pb that are absent in 12°Sn. Finally, the increase in the FWHM over that expected from thermal averaging at temperatures of the order 3.0 MeV is in accordance with the increase expected from the particle evaporation of the compound system.

Giant Resonances
Giant Resonances

Author: M. N. Harakeh

Publisher: Oxford Studies in Nuclear Phys

Published: 2001

Total Pages: 658

ISBN-13: 9780198517337

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Giant resonances are collective excitations of the atomic nucleus, a typical quantum many-body system. The study of these fundamental modes has in many respects contributed to our understanding of the bulk behavior of the nucleus and of the dynamics of non-equilibrium excitations. Although the phenomenon of giant resonances has been known for more than 50 years, a large amount of information has been obtained in the last 10 years. This book gives an up-to-date, comprehensive account of our present knowledge of giant resonances. It presents the experimental facts and the techniques used to obtain that information, describes how these facts fit into theoretical concepts and how this allows to determine various nuclear properties which are otherwise difficult to obtain. Included as an introduction is an overview of the main facts, a short history of how the field has developed in the course of time, and a discussion of future perspectives.

Giant Dipole Resonance in the Hot and Thermalized 132Ce Nucleus
Giant Dipole Resonance in the Hot and Thermalized 132Ce Nucleus

Author:

Publisher:

Published: 2006

Total Pages: 6

ISBN-13:

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The [gamma] decay of the Giant Dipole Resonance in the 132Ce compound nucleus with temperature up to ≈ 4 MeV has been measured. The symmetric 64Ni + 68Zn at E{sub beam} = 300, 400, 500 MeV and the asymmetric reaction 16O + 116Sn at E{sub beam} = 130, 250 MeV have been investigated. Light charged particles and [gamma] rays have been detected in coincidence with the recoiling compound system. In the case of the mass symmetric 64Ni induced reaction the [gamma] and charged particle spectral shapes are found to be consistent with the emission from a fully equilibrated compound nuclei and the GDR parameters are extracted from the data using a statistical model analysis. The GDR width is found to increase almost linear with temperature. This increase is rather well reproduced within a model which includes both the thermal fluctuation of the nuclear shape and the lifetime of the compound nucleus.

An Investigation of the Natural Line Shape of the Giant Dipole Resonance
An Investigation of the Natural Line Shape of the Giant Dipole Resonance

Author: Edward Franklin Gordon

Publisher:

Published: 1975

Total Pages: 0

ISBN-13:

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An investigation of photoabsorption experiments in the spherical nucleus (141)pr, the quasispherical dynamically deformed (197)Au, and the statically deformed (165)Ho showed that the best function for the energy dependence of the reduced transition probability is given by the Breit-Wigner form rather than the Lorentz form of a resonance function. However, the form of the resulting measured cross section is of the Lorentz type. The dependence of the giant resonance width Gamma on the excitation energy was also investigated. The variation was found to be less than 1% per MeV if one considered the known isovector E2 resonances above the giant dipole resonance. Best fit values of the reduced transition probabilities for the three nuclei are given and compared to (e, e') results.