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A Status Review on Symmetry Energy around Saturation Density: Theory. Collaborators : Wei-Zhou Jiang (SEU) Che Ming Ko and Jun Xu (TAMU) Bao-An Li and Chang Xu (TAMU-Commerce) De-Hua Wen (SCUT) Zhi-Gang Xiao and Ming Zhang (Tsinghua) Gao-Chan Yong (IMP)
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A Status Review on Symmetry Energy around Saturation Density: Theory Collaborators: Wei-Zhou Jiang (SEU) Che Ming Ko and Jun Xu (TAMU) Bao-An Li and Chang Xu (TAMU-Commerce) De-Hua Wen (SCUT) Zhi-Gang Xiao and Ming Zhang (Tsinghua) Gao-Chan Yong (IMP) Xin Wang, Bao-Jun Cai, Rong Chen, Peng-Cheng Chu, Kai-Jia Sun, Zhen Zhang, Hao Zheng (SJTU) Lie-Wen Chen (陈列文) (INPAC/Department of Physics, Shanghai Jiao Tong University. lwchen@sjtu.edu.cn) “Topical Workshop on Nuclear Symmetry Energy and Astrophysics”, Xi’an, December 17-19, 2010
Outline • The nuclear symmetry energy • Theoretical tools of determining the symmetry energy around normal density (1) Many-body approaches (2) Transport theory • Symmetry energy around normal density from: (1) Heavy ion collisions (2) Nuclear structures (3) Global nucleon optical potential • Symmetry energy around normal density and: (1) Nuclear effective interactions (2) Neutron stars • Summary and outlook p. 1
(Isospin) Symmetry energy term Symmetry energy including surface diffusion effects (ys=Sv/Ss) Sv ~ the nuclear matter symmetry energy at normal density The Nuclear Symmetry Energy Liquid-drop model W. D. Myers, W.J. Swiatecki, P. Danielewicz, P. Van Isacker, A. E. L. Dieperink,…… p. 3
Symmetric Nuclear Matter (relatively well-determined) The Nuclear Symmetry Energy Symmetry energy term (poorly known) The Nuclear Matter Symmetry Energy EOS of Isospin Asymmetric Nuclear Matter (Parabolic law) Isospin asymmetry p. 4
The Symmetry Energy The multifaceted influence of the nuclear symmetry energyA.W. Steiner, M. Prakash, J.M. Lattimer and P.J. Ellis, Phys. Rep. 411, 325 (2005). Nuclear Physics on the Earth Symmetry Energy Astrophysics and Cosmology in Heaven The symmetry energy is also related to some issues of fundamental physics: 1. The precision tests of the SM through atomic parity violation observables (Sil et al., PRC05) 2. Possible time variation of the gravitational constant (Jofre et al. PRL06; Krastev/Li, PRC07) 3. Non-Newtonian gravity proposed in grand unification theories (Wen/Li/Chen, PRL09) p. 5
QCD Phase Diagram QCD phase diagram in 3D: density ,temperature, and isospin p. 6
Theoretical tools of determining the symmetry energy around normal density(1) Many-body approaches (2) Transport theory p. 7
Nuclear Matter EOS: Many-Body Approaches The nuclear EOS cannot be measured experimentally, its determination thus depends on theoretical approaches • Microscopic Many-Body Approaches Non-relativistic Brueckner-Bethe-Goldstone (BBG) Theory Relativistic Dirac-Brueckner-Hartree-Fock (DBHF) approach Self-Consistent Green’s Function (SCGF) Theory Variational Many-Body (VMB) approach Green’s Function Monte Carlo Calculation Vlowk + Renormalization Group …… • Effective Field Theory Density Functional Theory (DFT) Chiral Perturbation Theory (ChPT) …… • Phenomenological Approaches Relativistic mean-field (RMF) theory Quark Meson Coupling (QMC) Model • Relativistic Hartree-Fock (RHF) • Non-relativistic Hartree-Fock (Skyrme-Hartree-Fock) Thomas-Fermi (TF) approximations • …… p. 8
Z.H. Li et al., PRC74, 047304(2006) Dieperink et al., PRC68, 064307(2003) BHF Esym: Many-Body Approaches p. 9
Chen/Ko/Li, PRC72, 064309(2005) Chen/Ko/Li, PRC76, 054316(2007) Esym: Many-Body Approaches p. 10
Esym: Many-Body Approaches RMF with chiral limits W.Z. Jiang, B.A. Li, and L.W. Chen, PLB653, 184 (2007) p. 11
Pure Nuetron Matter: Many-Body Approaches Resonant Fermi Gases with a Large Effective Range (PRL,2005) J. Piekarewicz, JPG37, 064038 (2010) Chiral 3NF (PRC,2010) Quantum MC (PRC,2010) Quantum MC (PRL,2008) p. 12
Theoretical tools of determining the symmetry energy around normal density (1) Many-body approaches(2) Transport theory p. 13
Transport Theory Transport Models Ni + Au, E/A = 45 MeV/A Transport Models for HIC’s at intermediate energies: N-body approaches CMD, QMD,IQMD,IDQMD, ImQMD,ImIQMD,AMD,FMD One-body approaches BUU/VUU, BNV, LV, IBL Relativistic covariant approaches RVUU/RBUU,RQMD… Central collisions Broad applications of transport models in astrophysics, plasma physics, electron transport in semiconductor and nanostructures, particle and nuclear physics, …… p. 14
Transport model for HIC’s Isospin-dependent BUU (IBUU) model • Solve the Boltzmann equation using test particle method • Isospin-dependent initialization • Isospin- (momentum-) dependent mean field potential • Isospin-dependent N-N cross sections • a. Experimental free space N-N cross section σexp • b. In-medium N-N cross section from the Dirac-Brueckner • approach based on Bonn A potential σin-medium • c. Mean-field consistent cross section due to m* • Isospin-dependent Pauli Blocking EOS p. 15
Transport model: IBUU04 Isospin- and momentum-dependent potential (MDI) Das/Das Gupta/Gale/Li, PRC67,034611 (2003) Chen/Ko/Li, PRL94,032701(2005) Li/Chen, PRC72, 064611 (2005) p. 16
Relativistic VUU/BUU Model Che Ming Ko, Ulrich Mosel, …… Relativistic Vlasov Equation + Collision Term… Wigner transform, Dirac + Fields Equation mean field drift Non-relativistic Boltzmann-Uehling-Uhlenbeck “Lorentz Force”→ Vector Fields pure relativistic term Collision term: p. 17
中能重离子碰撞输运模型 QMD模型 关于QMD的“推导”文献J. Aichelin, Phys. Rep.202, 233 (1991)有详细的讨论,其基本出发点同样是多体薛定谔方程,约化密度矩阵以及对BBGKY系列的截断,但一开始就引入相空间的概念,即对密度矩阵作富里叶变换得到所谓的Wigner密度(或称Wigner表示).从而直接将多体薛定谔方程表示为类似于经典输运方程的形式,这里我们给出有关的主要公式. AMD/FMD考虑了波函数的反对称化 p. 18
r 中能重离子碰撞输运模型 QMD模型 p. 19
中能重离子碰撞输运模型 QMD模型 p. 20
- 中能重离子碰撞输运模型 QMD模型 p. 21
Symmetry energy around normal density from: (1) Heavy ion collisions (2) Nuclear structures (3) Global nucleon optical potential p. 22
Pigmy/Giant resonances • Nucleon optical potential Symmetry energy probes Promising Probes of the Esym(ρ)(an incomplete list !) B.A. Li/L.W. Chen/C.M. Ko Phys. Rep. 464, 113(2008) p. 23
Esym: Isospin Diffusion in HIC’s Isospin Diffusion/Transport ______________________________________ How to measure Isospin Diffusion? PRL84, 1120 (2000) A+A,B+B,A+B X: isospin tracer p. 24
(1) Esym: Isospin Diffusion in HIC’s Symmetry energy, isospin diffusion,in-medium cross section Chen/Ko/Li, PRL94,032701 (2005) Chen/Ko/Li, PRC72,064309 (2005) Li/ Chen, PRC72, 064611(2005) Isospin Diffusion Data Esym(ρ0)=31.6 MeV L=88±25 MeV p. 25
Esym: Isoscaling in HIC’s Isoscaling in HIC’s Isoscaling observed in many reactions M.B. Tsang et al. PRL86, 5023 (2001) p. 26
(2) Esym: Isoscaling in HIC’s Constraining Symmetry Energy by Isocaling: TAMU Data Shetty/Yennello/Souliotis, PRC75,034602(2007); PRC76, 024606 (2007) Isoscaling Data Esym(ρ0)=31.6 MeV L=65 MeV Consistent with isospin diffusion data! p. 27
(3) Esym: Isospin diffusion and double n/p ratio in HIC’s ImQMD: n/p ratios and two isospin diffusion measurements Tsang/Zhang/Danielewicz/Famiano/Li/Lynch/Steiner, PRL 102, 122701 (2009) ImQMD: Isospin Diffusion and double n/p ratio Esym(ρ0)~28 - 34 MeV? L=38 - 103 MeV p. 28
Symmetry energy around normal density from: (1) Heavy ion collisions(2) Nuclear structures (3) Global nucleon optical potential p. 29
(4) Esym: Nuclear Mass in Thomas-Fermi Model Myers/Swiatecki, NPA 601, 141 (1996) Thomas-Fermi Model analysis of 1654 ground state mass of nuclei with N,Z≥8 Thomas-Fermi Model + Nuclear Mass Esym(ρ0)=32 .65 MeV L=49.9 MeV p. 30
Esym: Neutron Skin of Heavy Nuclei Chen/Ko/Li, PRC72,064309(2005) Good linear Correlation: S-L Oyamatsu et al., NPA634, 3 (1998); Brown, PRL85,5296(2000); Horowitz/Piekarewicz, PRL86, 5647 (2001); Furnstahl, NPA706, 85 (2002); Yoshida/Sagawa, PRC73, 044320 (2006) p. 31
(5) Esym: Droplet Model Analysis on Neutron Skin N-Skin data measured in antiprotonic atoms Droplet Model + N-skin Esym(ρ0)=28 - 35 MeV, L=55 ± 25 MeV p. 32
(6) Esym: Skyrme-HF Analysis on Neutron Skin Chen/Ko/Li/Xu PRC82, 024321(2010) N-Skin data of Sn isotopes Esym(ρ0)=30 MeV Neutron skin constraints on L and Esym(ρ0) are insensitive to the variations of other macroscopic quantities. p. 31
Esym: Pygmy Dipole Resonances Electric dipole strength in atomic nuclei By Deniz Savran p. 34
(7)、(8) Esym: Pygmy Dipole Resonances Pygmy Dipole Resonances of 130,132Sn Esym(ρ0)=32 ± 1.8 MeV L=43.125 ± 15 MeV Pygmy Dipole Resonances of 68Ni and 132Sn Esym(ρ0)=32.3 ± 1.3 MeV, L=64.8 ± 15.7 MeV p. 35
(9) Esym: IAS+LDM Danielewicz/Lee, NPA 818, 36 (2009) Esym from Isobaric Analog States + Liquid Drop model with surface symmetry energy IAS+Liquid Drop Model with Surface Esym Esym(ρ0)=32.5 ± 1 MeV L=94.5 ± 16.5 MeV p. 36
(10) Esym: LDM Liu/Wang/Li/Zhang, PRC (2010), in press [arXiv:1011.3865] Esym from Liquid Drop model with surface symmetry energy Liquid Drop Model with Surface Esym Esym(ρ0)=31.1 ± 1.7 MeV L=66.0 ± 13 MeV p. 37
Symmetry energy around normal density from: (1) Heavy ion collisions (2) Nuclear structures(3) Global nucleon optical potential p. 38
Esym: Global nucleon optical potential Xu/Li/Chen, PRC82, 054607 (2010) Single particle energy at Fermi surface = particle chemical potential Energy density Hugenholtz-Von Hove (HVH) Theorem Symmetry potential (Lane potential) p. 39
=26.11 MeV Esym: Global nucleon optical potential Xu/Li/Chen, PRC82, 054607 (2010) p. 40
(11) Esym: Global nucleon optical potential Xu/Li/Chen, PRC82, 054607 (2010) p. 41
Esymaround normal density 11 constraints on Esym (ρ0) and L from nuclear reactions and structures Esym(ρ0)=27 - 36 MeV L=30 - 90 MeV More accurate data are needed to obtain more stringent constraints! p. 42
Symmetry energy around normal density and:(1) Nuclear effective interactions (2) Neutron stars p. 43
Symmetry energy and Nuclear Effective Interaction Chen/Ko/Li, PRC76, 054316(2007) Chen/Ko/Li, PRC72,064309 (2005) Esym(ρ0)= 31.5 ±4.5 MeV and L=55 ± 25 MeV: only 55/118 Esym(ρ0)= 31.5 ±4.5 MeV and L=55 ± 25 MeV: only 8/23 p. 44
Symmetry energy around normal density and: (1) Nuclear effective interactions(2) Neutron stars p. 45
The Nuclear Symmetry Energy and Neutron Stars Lattimer/Prakash, Science 304, 536 (2004) core-crust transition • Neutron star has solid crust over liquid core. • Rotational glitches: small changes in period from sudden unpinning of superfluid vortices. • Evidence for solid crust. • 1.4% of Vela moment of inertia glitches. • Needs to know the transition density to calculate the fractional moment of inertia of the crust Link et al., PRL83,3362(99) p. 46
Locating the inner edge of neutron star crust pasta Significantly less than their fiducial values: ρt=0.07-0.08 fm-3 and Pt=0.65 MeV/fm3 Parabolic Law fails! Xu/Chen/Li/Ma, PRC79, 035802 (2009) Kazuhiro Oyamatsu, Kei Iida Phys. Rev. C75 (2007) 015801 Parabolic Approximation has been assumed !!! Xu/Chen/Li/Ma, ApJ 697, 1547 (2009) p. 47
(Empirical estimate Link et al., PRL83,3362(99)) (Isospin Diff) Constraints on M-R relation of NS Xu/Chen/Li/Ma, ApJ 697, 1547 (2009) Lattimer Prakash p. 48
Summary and outlook p. 49