Chaejun Song(SNU & PNU)
with M. Harada, C. Sasaki (Nagoya), D.-P. Min (SNU), T.- S. Park (KIAS)
hep-ph/0410124
Nuclear Phase Diagram
T(MeV)
Density(n0)
~150
~10
Early Universe(RHIC)
Color SuperconductorNeutron Star
Hadron Gas
Quark-Gluon Plasma
Phase Transition
Atomic Nuclei
Hadrons in Medium
Pions in medium kaons in medium
Heavy Baryon Chiral Effective Theory
• Very powerful for a system of a few baryons
• Systematic expansion with Q/
• Applications to nuclear matter-> new scale appears!
• Purpose: study dense medium in a systematic way
Our scales
• Small scale Q: excitation scale from Fermi surface (or pion mass)
• Large scale : chiral symmetry breaking scale
• Intermediate scale : Fermi momentum
Fp
Expansion scales
• Q/
• /
Fp
Free Fermion Gas
Analogy from HDETSee D.K. Hong: PLB 473, 118 (00)
2nd transformation and projection
Pions in Medium
nucleon-pion interaction
self-interactions of nucleons
Power Counting Rule
Vector Correlator
0NE 2EE
1NL 0
Suppressed by
Axial Vector Correlator
.A
A
0NE
2EE
1NL
0
1-loop:
Pion Decay Constants in Medium
Decomposition into 4 parts:
20
0
( ( ) , ) Re[ ]
( ( ) , ) Re[ ]
t tA
s t sA
p v p p p f
p v p p p f f
v ( ) /p E p
Matching with HBChPT at some
Our result:
HBChPT from Meissner et al., Ann. Phys. 297, 27 (02)
Suzuki et al., PRL92, 072302(04)
Pion Velocity in Medium
Lee et al., NPA 741, 161(04)
Damping of Pions
• No Damping in our valid range
We will study…
How to determine our parametersHow to introduce and deal with
cutoffs around Fermi surface (go to Fermi liquid!)
How to make it more preciseHow to go to higher densities and to
check various scenarios
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