The GDR in Hg and Eu nuclei from selected decay chains

• Published in: Nuclear physics. A Vol. 649; no. 1; pp. 115 - 122
• Main Authors: Camera, F., Bracco, A., Colombo, G., Leoni, S., Million, B., Mattiuzzi, M., Maj, A., Kmiecik, M., Herskind, B., Bark, R., Bearden, J., Gaardhøje, J.J., Ormand, E.W.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 29.03.1999
• ISSN: 0375-9474
• DOI: 10.1016/S0375-9474(99)00048-2

The γ-decay of the GDR in hot Hg and Eu isotopes has been measured in coincidence with selected low-energy γ-transitions of the evaporation residues. In the Hg case, the GDR width at finite temperature and at different spins was studied by analyzing simultaneously with the statistical model the high-energy γ-ray spectra associated with different residual nuclei and the fractions of residue cross-sections. The measured GDR width was found in good agreement with the predictions of the thermal fluctuations model. In the case of Eu, we have measured the high-energy γ-rays in coincidence with low-energy γ-transitions from different nuclear configurations of 143Eu in order to search for the GDR decay built on a superdeformed state. The analysis of the data shows a possible evidence of this state. The measured intensity indicates that the superdeformation survives only few MeV above the yrast line.