hadron to quark phase transition in the global color symmetry model of qcd
DESCRIPTION
Hadron to Quark Phase Transition in the Global Color Symmetry Model of QCD. Yu-xin Liu Department of Physics, Peking University. Collaborators: Guo H., Gao D.F., Chang L. Wang B., Song H.C., Chao J.Y. et al., at PKU; - PowerPoint PPT PresentationTRANSCRIPT
Hadron to Quark Phase Transition Hadron to Quark Phase Transition
in the Global Color Symmetry Model in the Global Color Symmetry Model
of QCDof QCD
Yu-xin Liu
Department of Physics, Peking University
Collaborators: Guo H., Gao D.F., Chang L. Wang B.,
Song H.C., Chao J.Y. et al., at PKU;
Wang F., Zong H.S., et al., at NJU;
Lue X.F. at SCU;
Zhao E.G. at ITP; Chao W.Q. at IHEP.
Outline
I. Introduction
II. The Framework
III. Numerical Results
IV. Remarks
I. IntroductionI. Introduction Two Puzzles in Current Physics (in T.D. Lee’s words):
Chiral Symmetry and its Spontaneous Breaking
Color Confinement
Characteristics Identifying
Quark Deconfinement
and Chiral Symmetry
Restoration:
Hadron Properties
Vacuum Structure
Lattice QCD, pQCD (Factorization, Re-summation), •••
Confinement Mechanism:Flux Tube, Center Vertex, ···Intuitive view?
NJL model, QMC, QMF, Truncated DSE, Instanton, GCM, ···
How the Chiral Symmetry is Restored ? Quark condensates are usually taken as characteristics of Vacuum Structure Order Parameters. Theoretical approaches: Composite-operator, Sum rules, QMC, Walecka model, Dirac-Brueckner, S-D Equation, Instanton dilute liquid model, …
Different results have been obtained!!
Chi. Sym.
C S B
(Comp.-Op., PRD41,1610(’90) ) ( QSR, NP A642, 171 (’98) )
(D-S Eq. PR C55, 1577(’97) ) (DS Eq. PR C57, 2821(’98) ) (IDLM, NP A642, 83(’98) )
(Walecka, PR C55, 521 (‘97))
Hadron Properties are essential in describing finite
nuclei and strong interaction matter
Effective mass
EMC effect, nuclear structure & reaction
Nucleon swell EMC effect
Bag constant Quark confinement
Theoretical Approaches:
Bag Models, QMC, QMF
bag constant, bag energy, radius
Phenomenologically!
QCD foundation ??? the GCM appears
*M
II. The Framework of the GCMII. The Framework of the GCM 1. The Main Point of Global Color Symmetry Model
R.T. Cahill, C.D. Roberts, Phys. Rev. D 32 (1985) 2419
Lue, Liu, Zhao, Zong, Phys. Rev. C 58 (1998) 1195
Prog. Part. Nucl. Phys. 39 (1997) 117; Phys. Rev. D49 (1994) 125; Phys. Rev. C53 (1996) 2410; ······ .
Effective degrees of freedom becomes quark and chiral mesons
2. GCM in Strongly Interacting Matter
Tniiq n )12(4
q q q q q q
3. The Scalar Quark Condensates
4. The mass and decay constant of pion
5. Relation Between the Chemical Potential and the Density
GCM, Global Color Symmetry Model: an effective field theory model of QCD
Truncated DSE NJL, ChPT QCD GCM Hadronisation Observables BM, QMC, QHD Lattice Hadron Correlation
With the GCM, one can explore the QCD foundation of bag models, the chiral symmetry breaking and restoration, the quark confinement and deconfinment, ••••••••••.
III. Numerical ResultsIII. Numerical Results
New approach to determine the vacuum configuration of the GCM
B = m in instanton model
Property of pion and sigma meson
Lue, Liu, Zhao, Zong, Phys. Rev. C 58 (1998) 1195
Relation between Relation between and and
)( 431
2
2
Nucleon bag constantNucleon bag constant
B(0)=(172 MeV)4
Y. X. Liu, et al, Nucl. Phys. A 695 (2001) 353, A 725 (2003) 127
Nucleon radius and massNucleon radius and mass
R(0)=0.7 fm m(0)=939 MeV
Y. X. Liu, et al, Nucl. Phys. A 695 (2001) 353; A725 (2003) 127.
Quark condensatesQuark condensates In nuclear matterIn nuclear matter
3)148(:: MeVqq
Y. X. Liu, et al, Phys. Rev. C68 (2003), 035204.
With a full gluon propagator
- relation nucleon properties
2
24
2
22
2
21
22
2
6
21
])1(ln[
422 4)(qeq tm
q
QCD
q
m
q
eDqD
0/ BB0/ RR 0/MM
Y. X. Liu, et al, Nucl. Phys. A 750 (2005), 324.
quark condensate
0.03 0.04 0.05 0.06 0.07 0.08 0.09 0.10
-0.03
-0.02
-0.01
0.00
0.01
0.02
second first zero
T (GeV)
0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.400.000
0.005
0.010
0.015
0.020
0.025T=30MeVT=60MeVT=70MeVT=90MeV
>
Quark Gluon mixed CondensateQuark Gluon mixed Condensate
Zhao Zhang, Wei-qin Chao, Phys. Lett. B 610 (2005), 235
The effective potential at and
00T
-0.08
-0.07
-0.06
-0.05
-0.04
-0.03
-0.02
-0.01
0.00
20s13s
20s12s
20s11s
30s
GeV
fm420
quark confinement results from the self-adjustment among/between quarks
The effective potential at finite and The effective potential at finite and
quark deconfinement and chiral symmetry
restoration may take place
T
The mass and decay constant of pionThe mass and decay constant of pion
Susceptibilities:Zong H. S. et al., Phys. Lett. B 557 (2003) 33Zong H. S. et al., Phys. Lett. B 576 (2003) 289Zong H. S. et al., Phys. Rev. D 67 (2003) 074004Zhang Z., Chao W.Q., Phys. Lett. B 612 (2005) 207
Axial vector vertexZong H. S. et al., Phys. Rev. C 66 (2002) 015201
New Approach to Evaluate the Quark Propagator at Finite Chemical Potential
Zong, Chang, Hou, Sun, Liu, Phys. Rev. C 71 (2005) 015205
IV. Remarks IV. Remarks The density dependence of the bag constant, the mass and radius of nucleons and the pion mass and decay constant are studied in an effective field theory model of QCD, namely the GCM The scalar local and nonlocal quark condensates are also investigated.
Calculated result 1: with the increase of the density
before a critical value is reached, the BN and MN
decrease, the M almost maintains constant, the RN,
the f and the condensates increase.
Calculated result 1: with the increase of the density before a critical value is reached, the BN and MN decrease, the M almost maintains constant, the RN, , , the f and the condensates increase.
Calculated result 2: at the critical density, the BN and MN vanish gradually, the M , f and the , etc, disappear suddenly, the RN becomes infinite.
Quark deconfinement and the chiral symmetry restoration phase transitions happen at the critical density.
Chiral symmetry restoration process: broken more strongly gradually, at least, at the same scale, then restored suddenly.
qq Gqq
Thanks !!!Thanks !!!