Suppression of soft nuclear bremsstrahlung in proton-nucleus collisions

Photon energy spectra up to the kinematic limit have been measured in 190 MeV proton reactions with light and heavy nuclei to investigate the influence of the multiple-scattering process on the photon production. Relative to the predictions of models based on a quasi-free production mechanism a strong suppression of bremsstrahlung is observed in the low-energy region of the photon spectrum. We attribute this effect to the interference of photon amplitudes due to multiple scattering of nucleons in the nuclear medium.Comment: 12 pages, 3 figures, submitted to Phys. Rev. Let

Light fragments production and isospin dependences in Sn+Ni and Sn+Al central collisions at 25MeV/A and 35MeV/A from reverse/isospin experiments

This paper presents the physical analysis results for the following reactions: 124Sn+64Ni, 124Sn+27Al, 124Sn+58Ni at 35MeV/A and 25MeV/A. The main goal of this studies was to find observables sensitive to isospin effects and to present the similarities/differences between the systems characterised by various charge asymmetry factor, defined as I = (NZ)=A. Theoretical simulations based on the Quantum Molecular Dynamics (QMD) model have been performed in order to compare them with the results of the analysis of experimental data. The first phase of the reaction was carried out with the code CHIMERA [1]. The sequential decay of hot fragments was simulated by the code COOLER [2]. The conclusions are as follows: there are observables sensitive to the isospin of the system, such as the Light Charged Particles (LCP) emission and their sensitivity is demonstrated more prominently in the analysis of central collisions at 35MeV/A. The theoretical calculations do not reproduce these relations well

Light Fragments Production and Isospin Dependences in Sn+Ni and Sn+Al Central Collisions at 25 MeV/A and 35 MeV/A from REVERSE/ISOSPIN Experiments

International audienceThis paper presents the physical analysis results for the following reactions: 124Sn + 64Ni, 124Sn + 27Al, 124Sn + 58Ni at 35 MeV/A and 25 MeV/A. The main goal of this studies was to find observables sensitive to isospin effects and to present the similarities/differences between the systems characterised by various charge asymmetry factor, defined as I = (N-Z)/A. Theoretical simulations based on the Quantum Molecular Dynamics (QMD) model have been performed in order to compare them with the results of the analysis of experimental data. The first phase of the reaction was carried out with the code CHIMERA [1]. The sequential decay of hot fragments was simulated by the code COOLER [2]. The conclusions are as follows: there are observables sensitive to the isospin of the system, such as the Light Charged Particles (LCP) emission and their sensitivity is demonstrated more prominently in the analysis of central collisions at 35 MeV/A. The theoretical calculations do not reproduce these relations well