2019 Impact factor 2.176
Hadrons and Nuclei
Eur. Phys. J. A 6, 275-288

Pre-equilibrium dipole excitation and $\gamma$-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 $\gamma$-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 $\gamma$-rays were evaluated in the statistical model framework while in the second one the $\gamma$-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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