Isospin study of projectile fragmentation Content 1 、 Isospin effect and EOS in asymmetry nuclei 2 、 Isotope Yields in projectile ragmentation 3 、 Summary and Outlook Wendong Tian Shanghai Institute of Applied Physics, CAS International Workshop on Nuclear Dynamics 2009 Shanghai

Equation of state of nuclear matter Dirac-Brueckner Variational+3-body(non-rel.) RMF(NL3) Density-Dependent couplings Chiral Perturbative Ch.Fuchs, WCI Final Report 2006 Nuclear matter diagram ： Liquid Gas transition

Isospin effect and EOS in asymmetry nucleus

Symmetry Energy E sym    MeV)     Expansion around   Pressure & compressibility Asy-stiff Asy-soft Pressure gradient Phys.Rep.410(2005) Asy-superstiff

Isoscaling Y 2 / Y 1 H.S. Xu et al, PRL85(2000) 716 M.B. Tsang et al. PRL, 86, 5023 (2001) Isospin yields of products in 2 isospin different reactions  、  and symmetry energy coeficient C sym

Symmetry energy coeficient and chemical potentials C sym (ρ,T) Exp V. Baran et al, Phys. Rep. 410, 335 (2005)

Isospin effect in projectile fragmentations  50MeV/u 36,40 Ar+ 64 Ni (EMPTY)  Isospin yields of projectile  Same settings in 2 reactions  Layout of experiment and Detectors, PID :B  -TOF-  E B  -TOF-  E Shanghai Insitute od Applied Pjysics, CAS, SHanghai Institute of Modern Physics, CAS, Lanzhou B  =2.32Tm and B  =2.36Tm

50MeV/u 36 Ar+ 64 Ni, PID of PF B  =2.32Tm dp/p=0.6%

50MeV/u 36 Ar+ 64 Ni, PID of PF after calibration Z%(N-Z) B  =2.32Tm dp/p=0.6% same rule of event selection

Isotope yields B  =2.32Tm dp/p=0.6%

Isotope yields B  =2.36Tm dp/p=0.6%

Isotope Yield Ratios and Isoscaling parameters B  =2.32Tm, 36,40 Ar+ 64 Ni

Isotope Yield Ratios and Isoscaling parameters B  =2.36Tm, 36,40 Ar+ 64 Ni

Epax Formula, K. Sümmerer and B. Blank, Phys. Rev. C 61, (2000). Theory simulation Isotope Yields, B  =2.32Tm( considering Transmission Rate)

Isotope Yields, B  =2.36Tm

Exp Isoscaling parameters Compared with Epax B  =2.32Tm, 36,40 Ar+ 64 Ni If  =4C sym *  (Z/A) 2 /T Then 0.4=0.19*C sym /T C sym /T=2.105 C sym =2.105*T T  10  ?? New dependence ?? Evaporation effect

Theory simulation Simple Code to derive necessary information Statistical Abration-Ablation model Brohm T and Schmidt K H 1994 Nucl. Phys. A Gimard J J and SchmidtK H 1991 Nucl. Phys. A Gaimard J-J and Schmidt K-H 1991 Nucl. Phys. A Fang D Q et al 2000 Phys. Rev. C Fang D Q et al 2001 Eur. Phys. J. A Cai X Z et al 1998 Phys. Rev. C In the SAA model, the nuclear reaction is described as two stages which occur in two distinctly different time scales. The first abrasion stage is the fragmentation reaction which describes the production of the pre-fragment with certain amount of excitation energy through the independent nucleon–nucleon collisions in the overlap zone of the colliding nuclei. The second stage is the evaporation process in which the system reorganizes due to excitation. It de-excites and thermalizes by the cascade evaporation of light particles using the conventional statistical model. The excitation energy for the projectile spectator is estimated by a simple relation of E=13.3 MeV where 13.3 is a mean excitationenergy for an abraded nucleon from the initial projectile.

Statistical Abration-Ablation (SAA) model simulation B  =2.32Tm, 36,40 Ar+ 64 Ni

a=5.0 a=10.0 a= Evaporation modify the isotope distribution, leads to the decreasing of  in SAA model. 2.Present analysis shows Epax reproduce the experiment better than SAA, but we need one model to reflect the scenario more precisely, so SAA will improved to fit the experimental result, further dynamic model will be tried.

Summmary 1.Isotopes yields of the projectile fragmentation from 2 isospin similar reactions were measured and compared in these 2 reactions. Isotope yield ratio were calculated, Isoscaling parameters  and  are extracted. 2.Isotope yields and isoscaling parameters are compared with those from Epax calculation, Epax can fit the isotope yield, but some discrepency still exist. 3. We simulated the reaction isotope yield by Statistical Abration- Ablation model, and try to fit the experimental result, but not successful yet, SAA simulation is still in progress. Simulation by other code if necessary will be made, and will try to analyze the symmetry energy coeficient C sym from exp and simulation.

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