Pre-equilibrium dipole excitation and
-ray fragment angular
correlation in the 32S + 74Ge reaction
M. Sandoli1,2 - A. Boiano1 - L. Campajola1 - A. De Rosa1,2 - A. D'Onofrio3,1 - G. Inglima1,2 - M. La Commara4 - A. Ordine1 - D. Pierroutsakou1 - V. Roca1,2 - M. Romano1,2 - M. Romoli1 - M. Trotta1,2 - F. Rizzo5,6 - F. Amorini5,6 - S. Tudisco5,6
1 INFN, Sezione di Napoli, Napoli, Italy
2 Università di Napoli ''Federico II'', Dipartimento di Scienze Fisiche, Napoli, Italy
3 Seconda Università di Napoli, Facoltà di Scienze Ambientali, Italy
4 GSI, Darmstadt, Germany
5 Università di Catania, Dipartimento di Fisica, Catania, Italy
6 INFN, Laboratorio Nazionale del Sud, Catania, Italy
Received: 24 March 1999 / Revised version: 17 May 1999 Communicated by D. Schwalm
Abstract
We report on the results obtained from the study of the 32S +74Ge
deep inelastic reaction at incident energy E = 320 MeV.
High-energy -rays were detected in an array of 6 seven-pack BaF2
clusters. Coincidence with complex fragments detected in 12
three-stage telescopes ensured the selection of peripheral reaction events.
In order to investigate the pre-equilibrium dipole strength excitation two
independent analyses were performed. In the first analysis the energy
spectra of the
-rays were evaluated in the statistical model
framework while in the second one the
-ray fragment angular
correlation with respect to the nuclear spin vector of the composite system
was studied. Both methods indicate the excitation of dipole strength in the
highly deformed dinucleus and provide dipole resonance parameter sets that
are in good agreement with each other.
PACS
25.70.-z Low and intermediate energy heavy-ion reactions -
24.30.Cz Giant resonances -
23.20.-g Electromagnetic transitions -
25.70.Lm Strongly damped collisions
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