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Thermal phase transition of color superconductivity with Ginzburg-Landau effective action on the lattice. M. Ohtani ( RIKEN ) with S. Digal ( Univ. of Tokyo ) T. Hatsuda ( Univ. of Tokyo ). Introduction GL effective action Phase diagram in weak gauge coupling
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Thermal phase transition of color superconductivity with Ginzburg-Landau effective action on the lattice M. Ohtani (RIKEN) with S. Digal (Univ. of Tokyo) T. Hatsuda (Univ. of Tokyo) • Introduction • GL effective action • Phase diagram in weak gauge coupling • Phase transition on the lattice • Summary XQCD, Aug 2 @ Swansea
Δ ~ 100MeV Tc ~ 60MeV Introduction T RHIC Quark-Gluon Plasma 170MeV Hadrons Color Superconductivity qq 0 N ☆ Cores μ ~400MeV • Non-perturbative analysis of colorsuper transition
{ ¶ no sign problem bosonic T-m dependence: m, li ,k,g ( discretize & rescale SUf (3) SUc(3) Higgs on Lattice ○ ○ ○ 2 couplings for quartic terms Ginzburg-Landau effective action Iida & Baym PRD 65 (2002)014022 GL action in terms of the quark pair field Ffc (x) & gauge field
l1 = l2 in weak coupling mean field without gluon Iida & Baym PRD 63 (2001)074018 mean field (ungauged) l2 normal CFL as T D F~D D l1 F = 0 normal 2SC unbound @ Tc(MF) 0 F~0 D 2nd order transition
l2 normal CFL normal2SCCFL l1 normal 2SC unbound 1st order transition weak gauge coupling limit Matsuura,Hatsuda,Iida,Baym PRD 69 (2004) 074012 mean field (ungauged) perturbative analysis l2 Normal CFL gluonic fluctuation l1 |F |3 term normal2SC unbound 2nd order transition
Phase diagram in weak gauge coupling CFL 2SC normal 1-T/Tc(MF)~k l2 unbound l1
l2 normal CFL normal2SCCFL l1 normal 2SC unbound Analytic results for large mean field (ungauged) perturbative analysis l2 Normal CFL gluonic fluctuation l1 normal2SC unbound 2nd order transition 1st order transition
Setup for Monte-Carlo simulation parameters { b = 5.1 0.7 bc in pure YM take several pairs of (l1, l2 ), scanning k Lattice size Lt = 2 , Ls = 12, 16, 24, 32, 40 with 3,000-60,000 configurations update pseudo heat-bath method for gauge field generalized update-algorithm of SU(2) Higgs-field Bunk, NP(Proc.Suppl) 42 (‘95), 556 @ RIKEN Super Combined Cluster
phase transition to ‘color super’ ¶ Tr Fx†Fx¹ 0 even in sym. phase thermal fluctuation broken phase plateau jump @ kc Phase identification Tr Fx†Fx (Tr F†F )1/2 update step large order param. ⇔ broken phase
F†FI・・・CFL a F†F~b ・・・2SC b ¶ F†F : gauge invariant diagonalization identifying the phases by eigenvalues of FyF matrix elements of F†F
Phase diagram with li fixed k CFL Color Superconducting state ● Similar trends with SU(2) Higgs ● no clear signal of end points as li 0.16 2SC normal (Quark-Gluon Plasma) 0.08 l1 =l2 =.0005 Hadron b 5.6 5.1 3.6 4.8
Hysteresis : different configs. with same k CFL ß Put 3 configs in spatial sub-domain 2SC ß Thermalize it with fixed k 1st order transition: Hysteresis & boundary shift initial config. = a thermalized config. with slightly different k CFL 2SC Polyakov loop normal k
perturbative analysis l2 CFL 2SCCFL l1 2SC unbound Phase diagram with b fixed lattice simulation l2 CFL CFL w/metastable 2SC 2SC CFL metastable 2SC: 2SC observed in hysteresis & disappeared in boundary shift test 2SC l1 1st order transition
●largest barrier btw normal &CFL ●$metastable 2SC Free energy by perturbation Iida,Matsuura,Tachibana,Hatsuda PRD 71 (2005)054003 D1 = D2 2 D1 F†F~D1 D3 CFL normal 2SC D3
Summary and outlook • GL approach with quark pair field F & gauge on lattice • SU(3) Higgs model • eigenvalues of F†F to identify the phases 1st order trans. toCFL & 2SC phases in coupling space • We observed hysteresis. transition points boundary shift with mixed domain config. • $metastable 2SC state in transition from normal to CFL, which is consistent with perturbative analysis • charge neutrality, quark mass effects, correction to scaling, phase diagram in T-m, …