Physics Letters B (Jul 2018)

Mapping the demise of collective motion in nuclei at high excitation energy

  • D. Santonocito,
  • Y. Blumenfeld,
  • C. Maiolino,
  • C. Agodi,
  • R. Alba,
  • G. Bellia,
  • R. Coniglione,
  • A. Del Zoppo,
  • F. Hongmei,
  • E. Migneco,
  • P. Piattelli,
  • P. Sapienza,
  • L. Auditore,
  • G. Cardella,
  • E. De Filippo,
  • E. La Guidara,
  • C. Monrozeau,
  • M. Papa,
  • S. Pirrone,
  • F. Rizzo,
  • A. Trifiró,
  • M. Trimarchi,
  • H.X. Huang,
  • O. Wieland

Journal volume & issue
Vol. 782
pp. 427 – 432

Abstract

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High energy gamma-rays from the 116Sn + 24Mg reaction at 23A MeV were measured using the MEDEA detector at LNS – INFN Catania. Combining this new data with previous measurements yields a detailed view of the quenching of the Giant Dipole Resonance as a function of excitation energy in nuclei of mass A in the range 120÷132. The transition towards the disappearance of the dipole strength, which occurs around 230 MeV excitation energy, appears to be remarkably sharp. Current phenomenological models give qualitative explanations for the quenching but cannot reproduce its detailed features. Keywords: Giant Dipole Resonance, Hot nuclei, Fusion reactions, Statistical Model