Pre-equilibrium γ-ray emission induced in theCa40+Ca48system at 10 MeV/nucleon and isospin equilibration processes
| Autor: | G. Cardella, G. Lanzalone, S. Pirrone, F. Rizzo, P. Figuera, M. Papa, Alessia Di Pietro, Wendong Tian, F. Amorini, Domenico Santonocito, Gianluca Giuliani |
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| Rok vydání: | 2005 |
| Předmět: | |
| Zdroj: | Physical Review C. 72 |
| ISSN: | 1089-490X 0556-2813 |
| Popis: | In the present paper we have studied \ensuremath{\gamma}-ray emission in coincidence with charged particles measured in binary processes for the collisions $^{40}\mathrm{Ca}+^{48}\mathrm{Ca}$, $^{46}\mathrm{Ti}$ at 10 MeV/nucleon. The comparison between \ensuremath{\gamma}-ray yields, obtained under identical conditions on the charged particles detected in coincidence, shows an extra yield of around 15 MeV for the $^{40}\mathrm{Ca}+^{48}\mathrm{Ca}$ collision. The analysis of the \ensuremath{\gamma}-charged fragment coincidence events, along with the study performed with the dynamical model CoMD-II, explains this effect as the result of a giant dipole resonance emission from the intermediate system, characterized by a high degree of coherence. The performed study aims to establish a link among pre-equilibrium \ensuremath{\gamma}-ray emission, initial charge/mass ratio memory effects in the intermediate system for the $^{40}\mathrm{Ca}+^{48}\mathrm{Ca}$ system at short time, and the achievement of a substantial charge/mass ratio or isospin equilibration of the primary fragments formed at longer time. Moreover, the presence of a remarkable extra yield in a restricted range of the \ensuremath{\gamma}-ray spectra suggests that this equilibration process evolves through a quasiresonant mechanism. |
| Databáze: | OpenAIRE |
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