10 research outputs found
Triaxiality in the interacting boson model
The signature splitting of the -vibrational band of several Ru, Pd,
Xe, Ba, Os and Pt isotopes is analyzed in the framework of the interacting
boson model (IBM). The nuclei studied are close to the -unstable SO(6)
limit of the IBM and have well-known bands. It is shown that in most
nuclei the signature splitting is better reproduced by the inclusion of a
three-body interaction between the bosons. In none of the nuclei evidence
for a stable, triaxial ground-state shape is found.Comment: Accepted for publication in Nuclear Physics
Triaxiality in the interacting boson model
The signature splitting of the gamma-vibrational band of several Ru, Pd, Xe, Ba, Os and Pt isotopes is analyzed in the framework of the interacting boson model (IBM). The nuclei studied are close to the gamma-unstable SO(6) limit of the IBM and have well-known gamma bands. It is shown that in most nuclei the signature splitting is better reproduced by the inclusion of a three-body interaction between the d bosons. In none of the nuclei evidence for a stable, triaxial ground-state shape is found. (C) 2008 Elsevier B.V. All rights reserved
Experimental study of the Ca+ Ca reactions at 35 MeV/nucleon
In this article we investigate Ca+Ca peripheral and semi-peripheral reactions at 35 MeV/nucleon. Data were obtained using the unique coupling of the VAMOS high acceptance spectrometer and the INDRA charged particle multidetector.The spectrometer allowed high resolution measurement of charge, mass and velocity of the cold projectile-like fragment (PLF), while the INDRA detector recorded coincident charged particles with nearly acceptance.The measured isotopic composition of the PLF identified in VAMOS and the average light charged particle (LCP) multiplicities are promising observables to study the isospin diffusion.The detection of the PLF in coincidence with LCP allows the reconstruction of the mass, charge and excitation energy of the associated initial quasi-projectile nuclei (QP), as well as the extraction of apparent temperatures.We investigate the suitability of the isoscaling method with the PLF and the experimental reconstructed QP.The extracted and isoscaling parameters present a dependence on the considered system combination that could justify their use as a surrogate for isospin asymmetry in isospin transport studies.The reconstruction of the QP allows to observe an evolution of the with the size of the QP, the latter being consistent with a strong surface contribution to the symmetry energy term in finite nuclei. This leads to the conclusion that the reconstruction of the primary source is mandatory for the study of the symmetry energy term based on the isoscaling method for such reactions
Experimental study of the Ca+ Ca reactions at 35 MeV/nucleon
International audienceIn this article we investigate Ca+Ca peripheral and semi-peripheral reactions at 35 MeV/nucleon. Data were obtained using the unique coupling of the VAMOS high acceptance spectrometer and the INDRA charged particle multidetector.The spectrometer allowed high resolution measurement of charge, mass and velocity of the cold projectile-like fragment (PLF), while the INDRA detector recorded coincident charged particles with nearly acceptance.The measured isotopic composition of the PLF identified in VAMOS and the average light charged particle (LCP) multiplicities are promising observables to study the isospin diffusion.The detection of the PLF in coincidence with LCP allows the reconstruction of the mass, charge and excitation energy of the associated initial quasi-projectile nuclei (QP), as well as the extraction of apparent temperatures.We investigate the suitability of the isoscaling method with the PLF and the experimental reconstructed QP.The extracted and isoscaling parameters present a dependence on the considered system combination that could justify their use as a surrogate for isospin asymmetry in isospin transport studies.The reconstruction of the QP allows to observe an evolution of the with the size of the QP, the latter being consistent with a strong surface contribution to the symmetry energy term in finite nuclei. This leads to the conclusion that the reconstruction of the primary source is mandatory for the study of the symmetry energy term based on the isoscaling method for such reactions