761 articles – 7589 references  [version française]
 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.
 Research team: Dynamique et thermodynamique nucléaire
 Subject(s) : Physics/Nuclear Experiment
 Fulltext link: http://fr.arXiv.org/abs/1206.0697
 in2p3-00704236, version 1 http://hal.in2p3.fr/in2p3-00704236 oai:hal.in2p3.fr:in2p3-00704236 From: Michel Lion <> Submitted on: Tuesday, 5 June 2012 09:10:20 Updated on: Friday, 10 May 2013 10:49:34