The γ decay of the Giant Dipole Resonance in 132Ce nuclei has been measured in the compound temperature range 2.5 - 4.1 MeV using a symmetric reaction 64Ni (300, 400, 500 MeV) + 68Zn and an asymmetric one 16O (130, 250 MeV) + 116Sn. Both cases produce 132Ce compound nuclei at the same excitation energy and angular momentum. Light charged particles and evaporation residues have been measured in coincidence with high energy γ-rays. The data show that pre-equilibrium emission is present only in the asymmetric reaction while only statistical emission from a fully equilibrated 132Ce compound is present in the symmetric one. The measured Giant Dipole Resonance widths show an almost linear increase with the effective temperature. Such a measured trend is reproduced by the thermal fluctuation model which includes the lifetime of the compound nucleus. The comparison between the high energy γ-ray spectra in the symmetric and asymmetric reactions shows a dynamic dipole emission in the 16O-induced reaction. The yield is consistent with what has been previously measured in the same mass and energy range.
|Titolo:||Progress in the study of the gamma decay of the giant dipole resonance in very hot rotating nuclei|
|Autori interni:||CAMERA, FRANCO (Ultimo)|
BRACCO, ANGELA (Primo)
|Settore Scientifico Disciplinare:||Settore FIS/01 - Fisica Sperimentale|
Settore FIS/04 - Fisica Nucleare e Subnucleare
|Data di pubblicazione:||2007|
|Digital Object Identifier (DOI):||10.1016/j.nuclphysa.2007.01.083|
|Appare nelle tipologie:||01 - Articolo su periodico|
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