1. China-Japan Nuclear Physics 2006
强相互作用夸克－介子－双夸克等离子体的边界The Boundary of A Strongly Coupled Quark-Meson-Diquark Plasma 庄鹏飞(清华大学) Pengfei Zhuang (Tsinghua University)
1. Motivation Quarks at MF + Mesons & Diquarks at RPA in NJL Resonances Numerical Results & Conclusion
with Lianyi He and Meng Jin
China-Japan Nuclear Physics 2006

2. China-Japan Nuclear Physics 2006
1. Motivation
Shuryak, 2004: What RHIC tells us? Strongly coupled Quark-Gluon Plasma, HG to sQGP to wQGP Particles in sQGP are not quasiparticles but resonances
pair dissociation line
BCS Tc
(1.5-2) Tc
BEC
sQGP (Shuryak)
Color SuperConductor
While there is no confinement, NJL is an often used effective model in the investigation of QCD phase transitions at moderate T and U what we want to do: boundary of a strongly coupled quark-meson-diquark plasma
China-Japan Nuclear Physics 2006

3. China-Japan Nuclear Physics 2006
2. Quarks at MF + Mesons & Diquarks at RPA in NJL
chiral, pion and color condensates
MF quark propagator in Nambu-Gorkov space
China-Japan Nuclear Physics 2006

4. China-Japan Nuclear Physics 2006
2. Quarks at MF + Mesons & Diquarks at RPA in NJL
diquark & meson polarization functions
diquark & meson propagators at RPA
pole determines diquark & meson masses
for mesons
for diquarks D1 & D2
for diquarks D3
residue at the pole determines coupling constants
leading order of 1/N for quarks, and next to leading order for mesons & diquarks.
symmetry breaking, Goldstone modes, symmetry restoration, hadron properties.
China-Japan Nuclear Physics 2006

5. China-Japan Nuclear Physics 2006
2. Quarks at MF + Mesons & Diquarks at RPA in NJL
Gapless CSC induced by mismatched Fermi surfaces: Huang, Liao, Zhuang: PRD2002,2003, Huang,Shovkovy,PLB2003
Goldstone modes in CSC and Pion superfluidity, He, Jin, Zhuang: PLB2005, PRD2005,2006
Competition between Gapless state and LOFF state He, Jin, Zhuang: PRB2006, PRD2006
China-Japan Nuclear Physics 2006

6. China-Japan Nuclear Physics 2006
3. Resonances
critical temperature for chiral restoration
mesons & diquarks are in bound states
mesons & diquarks are in resonant states
pair dissociation line
BCS Tc
(1.5-2) Tc
BEC
sQGP (Shuryak)
China-Japan Nuclear Physics 2006

7. China-Japan Nuclear Physics 2006
4. Numerical Results & Conclusion
with the assumption
1) The boundary of meson (diquark) state is determined by the disappearance of the corresponding pole.
2) The maximum limit temperature and the maximum chemical potential are about 2 times the critical values for chiral phase transition, which agree with the lattice calculation.
3) Meson state can survive at higher temperatures, which agrees with the qualitative estimation.
Thanks for your patience
China-Japan Nuclear Physics 2006