2020 Impact factor 3.043
Hadrons and Nuclei
Eur. Phys. J. A 4, 69-82

Pre-equilibrium $\gamma$ ray emission in different reaction mechanisms at 8 MeV/nucleon

M. Papa1 - F. Amorini2,3 - M. Cabibbo2,3 - G. Cardella1 - A. Di Pietro2,4 - P. Figuera2 - A. Musumarra2,5 - G. Pappalardo2,3 - F. Rizzo2,3 - S. Tudisco2,3

1 Istituto Nazionale di Fisica Nucleare - Sezione di Catania (Italy)
2 Istituto Nazionale di Fisica Nucleare - Laboratorio Nazionale del Sud Catania (Italy)
3 Dipartimento di Fisica Universitá di Catania (Italy)
4 Department of Physics and Astronomy, University of Edinburgh JCMB, King's Building, Scotland
5 CEA/DSM/DAPNIA/SPhN, Saclay, France

Received: 15 April 1998 / Revised version: 8 June 1998 Communicated by V. Metag

Abstract
Recent experimental results on particles-$\gamma$ coincidence measurements on the systems 12C+64Ni and 35Cl+64Ni at about 8 MeV/nucleon are interpreted as due to the effect of a Dipole pre-equilibrium emission produced during the damping of the proton-neutron relative collective motion in very deformed intermediate systems formed in the first instants of the collision. The pre-equilibrium effects are evaluated through semiclassic kinetic theories and through modified statistical approach to include non-stationary effects in Fusion processes, Massive Transfer reactions (in the 12C+64Ni system) and in Binary Dissipative reactions (in the 35Cl+64Ni system). In particular the study performed on the dipole molecular component allows to establish a link between the above phenomenon and the charge and mass transfer process in quasi-peripheral reactions.

PACS
24.30.Cz Giant resonances - 25.70.-z Low and intermediate energy heavy-ion reactions


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