615 articles – 3069 Notices  [english version]
 HAL : in2p3-00704236, version 1
 arXiv : 1206.0697
 Physical Review C 86 (2012) 014610
 Correlations between emission timescale of fragments and isospin dynamics in $^{124}$Sn+$^{64}$Ni and $^{112}$Sn+$^{58}$Ni reactions at 35 AMeV
 (2012)
 We present a new experimental method to correlate the isotopic composition of intermediate mass fragments (IMF) emitted at mid-rapidity in semi-peripheral collisions with the emission timescale: IMFs emitted in the early stage of the reaction show larger values of $<$N/Z$>$ isospin asymmetry, stronger angular anisotropies and reduced odd-even staggering effects in neutron to proton ratio $<$N/Z$>$ distributions than those produced in sequential statistical emission. All these effects support the concept of isospin "migration", that is sensitive to the density gradient between participant and quasi-spectator nuclear matter, in the so called neck fragmentation mechanism. By comparing the data to a Stochastic Mean Field (SMF) simulation we show that this method gives valuable constraints on the symmetry energy term of nuclear equation of state at subsaturation densities. An indication emerges for a linear density dependence of the symmetry energy.
 équipe(s) de recherche : Dynamique et thermodynamique nucléaire
 Thème(s) : Physique/Physique Nucléaire Expérimentale
 Lien vers le texte intégral : http://fr.arXiv.org/abs/1206.0697
 in2p3-00704236, version 1 http://hal.in2p3.fr/in2p3-00704236 oai:hal.in2p3.fr:in2p3-00704236 Contributeur : Michel Lion <> Soumis le : Mardi 5 Juin 2012, 09:10:20 Dernière modification le : Vendredi 10 Mai 2013, 10:49:34