Nature of the pygmy dipole resonance in Ce-140 studied in (alpha, alpha 'gamma) experiments

D. Savran*, M. Babilon, A.M. van den Berg, M.N. Harakeh, J. Hasper, A. Matic, H.J. Wörtche, A. Zilges

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

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Abstract

A concentration of electric-dipole excitations below the particle threshold, which is frequently denoted as the pygmy dipole resonance, has been studied in the semimagic nucleus Ce-140 in (alpha, alpha(')gamma) experiments at E-alpha=136 MeV. The technique of alpha-gamma coincidence experiments allows the separation of E1 excitations from states of other multipolarities in the same energy region and provides an excellent energy resolution to allow a detailed analysis for each state. The experimental results show that the PDR splits into two parts with different nuclear structure: one part which is excited in (alpha, alpha(')gamma) as well as (gamma, gamma(')) experiments and one part which is excited only in (gamma, gamma(')).

Original languageEnglish
Article number172502
Number of pages4
JournalPhysical Review Letters
Volume97
Issue number17
DOIs
Publication statusPublished - 27-Oct-2006

Keywords

  • PHOTONEUTRON CROSS-SECTIONS
  • BIG-BITE SPECTROMETER
  • MONOENERGETIC PHOTONS
  • BOUND-STATES
  • NUCLEI
  • STRENGTH
  • ENERGY
  • EXCITATIONS
  • PHOTODISINTEGRATION
  • PB-208

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