1. Nuclear Symmetry Energy and Compact Stars
“simple-minded approach”
Hyun Kyu Lee Hanyang University
WCU-HIM meeting on “Dense Matter Physics” Oct. 31, 2009

2. Introduction Nuclear matter (finite or infinite volume)
consituents: nucleon (proton and neutron)
total number: N =
density :
Energy of nuclear matter, U
energy per nucleon: E = U / N
energy density : = U / V = E

3. energy per nucleon
Free - nucleon matter
Pauli exclusion principle

5. symmetry energy factor, S(n)
Model dependent symmetry energy factors
Prakash et al. (1994)
B.-A. Li et al. (2005)
Piekarewicz and Centelles (2009)

6. Nuclear Symmetry Energy Factors
(KK and H.K. Lee, arXiv: )
Diverse predictions at u > 1 !

7. B-A. Li et al

9. Neutron star Astrophysical Compact Object n, p, e, muon, pion,
Chemical equilibrium ( ) and
Electrical charge neutrality ( ) between particles.
Pressure Gravity: TOV equation
Equation of State(EOS)
n, p, e,
muon, pion,
kaon, …
R ~ km
M ~ 1-3 Msun
Free-fermion gas
Nuclear Physics (Symmetry Energy)
Hadron Physics

10. Electron Chemical Potential
(KK and H.K. Lee, arXiv: )
chemical equilibrium and charge neutrality

11. Kaon Condensation Threshold
(KK and H.K. Lee, arXiv: )
(Brown et al, 2008)
No kaon condensation ?

12. Equation of States for NS-like Compact Object
Total energy density and pressure
: (Dimensionless) Fermi momentum
: Compton wavelength
( Shapiro & Teukolsky )

13. TOV(Tolmann-Oppenheimer-Volkov) Equation
Gravity Pressure

14. M-R M-nc M-rhoc @ Mmax of each models Free SF SFSU 0.71 Msun, 9.27 km
SNL3
Salpha=1
0.71 Msun, 9.27 km
2.00 Msun, km
1.73 Msun, km
2.10 Msun, km
0.39 Msun, km
M-R
M-nc
M-rhoc

15. Radial Dependence of Compositions in Compact ObjectsSF
SFSU
SNL3
Salpha=1

16. Radial Dependence of Electron Chemical Potential and Nucleon Number Density
Electron chemical potential vs. distance from center of compact Mmax of each models
Nucleon number density vs. distance from center of compact Mmax of each models

18. < Nuclear Symmetry Energy at Higher Density >
-Theory: Models for Nuclear Inetraction Effective Theories for QCD
- Experiments: CBM/FAIR, ALICE/LHC, RHIC…
- Observations: Neutron Stars, Black Holes, .. , Gravitaional Waves, ..
Observables ??!!