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9. Vector Manifestation in Hot and/or Dense Matter. M.H. and C.Sasaki, Phys. Lett. B 537 , 280 (2002) M.H., Y.Kim and M.Rho, Phys. Rev. D 66 , 016003 (2002) M.H., Y.Kim, M.Rho and C.Sasaki, Nucl. Phys. A 727 , 437 (2003) M.H. and C.Sasaki, hep-ph/0304282.
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9. Vector Manifestation in Hot and/or Dense Matter • M.H. and C.Sasaki, Phys. Lett. B 537, 280 (2002) • M.H., Y.Kim and M.Rho, Phys. Rev. D 66, 016003 (2002) • M.H., Y.Kim, M.Rho and C.Sasaki, Nucl. Phys. A 727, 437 (2003) • M.H. and C.Sasaki, hep-ph/0304282
Perturbative QCD (asymptotic freedom) Heavy Quark Symmetry Chiral Symmetry Theory of weakly interacting mesons Limitof Parameters &SymmetryProperties in QCD
他の極限 ? QCD のさらなる解明への手がかり
T μ B ☆ 有限温度・有限密度QCD • 相構造の変化 • ハドロンの性質の変化 宇宙の進化 クォーク・グルーオン・プラズマ相 相 転 移 カラー超伝導相 ハドロン相 コンパクト天体 (中性子星・クォーク星) 通常の核物質
J-PARC (原研 + KEK) • GSI ◎ 有限温度・有限密度QCDに関する実験 温度 これまでの実験・稼動中の実験 • SIS (GSI; Germany) • AGS (Brookhaven; USA) • SPS (CERN;Swintzerland) • RHIC (Brookhaven; USA) クォーク・グルーオン・プラズマ相 実験計画 • LHC (CERN) ハドロン相 密度
QCDの情報 • 有限温度・有限密度でのハドロンの性質 • QGP相でのクォーク・グルーオンの性質 • 終状態のハドロン(π, P等)の観測 ◎ レプトン対のエネルギースペクトルの観測 ・・・
☆ 有限温度・有限密度ではハドロンの性質は真空中とは異なる ! 分布 真空中と同じ分布関数 では説明できない レプトン対のエネルギー
☆ 実験を説明するシナリオ 1. ドロッピング ρ・・・ m (T, μ ) → 小 , Γ(T, μ ) → 小 for T, μ → 大 ρ ρ B B B 2. コリジョン・ブロードニング ・・・ Γ → 大, m~ ほぼ一定 for T, μ → 大 ρ ρ B コリジョン・ブロードニング ドロッピング ρ
VM predicts dropping rho meson mass. Other predictions of VM ?
Outline of Section 9 9.1 Why VM in hot and/or dense QCD ? 9.2 Vector manifestation in terms of chiral representation 9.3 Intrinsic temperature and/or density dependence 9.4 VM conditions at Tc and μc 9.5 Vector meson mass in the VM at Tc 9.6 Pion decay constants and pion velocity at Tc 9.7 Determination of the critical temperature 9.8 Vector and axial-vector susceptibilities at Tc 9.9 Violation of vector dominance at Tc 9.10 Vector manifestation in dense matter
9.2 Vector Manifestation in terms of Chiral Representation
☆ Vector Manifestation ・・・ Wigner realization of chiral symmetry ρ = chiral partner of π c.f. conventional linear-sigma model manifestation scalar meson = chiral partner of π
Quark Structure and Chiral representation coupling to currents and densities (S. Weinberg, 69’)
Chiral Restoration vector manifestation linear sigma model
9.3 Intrinsic Temperature and/or Density Dependence
☆ Application of Wilsonian matching at T > 0 and/or μ> 0 high energy QCD quarks and gluons Λ matching HLS ρ, π (and quasiquark) Intrinsic temperature and/or density dependence of bare parameters of the HLS hadronic thermal loop effects dense loop effects low energy Quantum effects physical quantities
9.4 VM Conditions at Tc and/or μc
How do we realize Π → Π in hadronic picture ? V A • assumption ・・・ 2ndor weak 1st order phase transition for T → Tc and/or μ→μc ◎ Chiral symmetry restoration is characterized by
☆ Bare Parametes ・・・Intrinsic T and/or m dependences ◎ VM conditions for T → T and/or c ◎ current correlators in the bare HLS
9.5 Vector meson mass in the VM at the critical temperature
9.6 Pion decay constants and pion velocity at the ctrical temperature
☆ Temporal and spatial pion decay constants ; ; hadronic thermal correction parametric pion decay constant renormalized in the low-energy limit (Quantum corrections are included.)
・ VM condition : ☆ VM at Tc ◎ Pion velocity at Tc ・ Pion velocity becomes speed of light ⇔ cf: Vπ = 0 in the pion only theory (D.T.Son and M.Stephnov, PRL 88, 202302)
9.7 Determination of the critical temperature
・ RGE at Tc ・ Wilsonian matching
9.8 Vector and Axial-vector Susceptibilities at Critical Temperature M.H. Y.Kim, M.Rho and C.Sasaki, Nucl. Phys. A 727, 437 (2003)
☆ Vector and Axial-vector Susceptibilities at : vector current : axialvector current must be satisfied at Chiral Restoration M.H. Y.Kim, M.Rho and C.Sasaki, Nucl. Phys. A 727, 437 (2003)
9.9 Violation of vector dominance at the critical temperature M.H. and C.Sasaki, hep-ph/0304282
Vector Dominance ☆ Pion EM form factor (tree level at T = 0)
☆ parametera at T>0 ・ VM condition : ; ◎ near Tc・・・ intrinsic thermal effect becomes important Large violation of vector dominance !
9.10 Vector Manifestation in Dense Matter M.H., Y.Kim and M.Rho, Phys. Rev. D 66, 016003 (2002)
Please note that, in this subsection, I use μ ・・・baryon chemical potential M・・・ renormalization scale
☆ Inclusion of quasiquark near the critical point near the critical point G.E.Brown and M.Rho, Phys. Rept. 363, 85 (2002) Lagrangian
☆ Bare Parametes ・・・Intrinsic density dependences ◎ VM conditions for μ → μ c ◎ current correlators in the bare HLS