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basic hadronic SU(3) model generating a critical end point in a hadronic model revisited including quark degrees of freedom phase diagram – the QH model excluded volume corrections, phase transition J. Steinheimer, V. Dexheimer, P. Rau, H. Stöcker, SWS FIAS; Goethe University, Frankfurt OUTLINE Hot and dense matter in quark-hadron models ICPAQGP, Goa 2010
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A) SU(3) interaction ~ Tr [ B, M ] B, ( Tr B B ) Tr M B) meson interactions ~ V(M) = 0 0 = 0 0 C) chiral symmetry m = m K = 0 explicit breaking ~ Tr [ c ] ( m q q q ) light pseudoscalars, breaking of SU(3) _ _ hadronic model based on non-linear realization of chiral symmetry degrees of freedomSU(3) multiplets: ~ 0 ~ baryons (n,Λ, Σ, Ξ) scalars ( , , 0 ) vectors (ω, ρ, φ), pseudoscalars, glueball field χ _ _ _ _ _ _
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fit parameters to hadron masses ’’ mesons Model can reproduce hadron spectra via dynamical mass generation p,n K K* ** **
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Lagrangian (in mean-field approximation) L = L BS + L BV + L V + L S + L SB baryon-scalars: L BS = - B i (g i + g i + g i ) B i L BV = - B i (g i + g i + g i ) B i baryon-vectors: meson interactions: L BS = k 1 ( 2 + 2 + 2 ) 2 + k 2 /2 ( 4 + 2 4 + 4 + 6 2 2 ) + k 3 2 - k 4 4 - 4 ln / 0 + 4 ln [( 2 - 2 ) / ( 0 2 0 )] explicit symmetry breaking: L SB = c 1 + c 2 _ _ L V = g 4 ( 4 + 4 + 4 + β 2 2 ) / / / I I
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parameter fit to known nuclear binding energies and hadron masses 2d calculation of all measured (~ 800) even-even nuclei error in energy (A 50) ~ 0.21 % (NL3: 0.25 %) (A 100) ~ 0.14 % (NL3: 0.16 %) good charge radii r ch ~ 0.5 % (+ LS splittings) SWS, Phys. Rev. C66, 064310 (2002) relativistic nuclear structure models + correct binding energies of hypernuclei compressibility ~ 223 MeV asymmetry energy ~ 31.9 MeV binding energy E/A ~ -15.2 MeV saturation ( B ) 0 ~.16/fm 3 phenomenology: 200 - 250 MeV 30 - 35 MeV Nuclear Matter and Nuclei
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phase transition compared to lattice simulations heavy states/resonance spectrum is effectively described by single (degenerate) resonance with adjustable couplings reproduction of LQCD phase diagram, especially T c, μ c + successful description of nuclear matter saturation phase transition becomes first-order for degenerate baryon octet ~ N f = 3 with T c ~ 185 MeV T c ~ 180 MeV µ c ~ 110 MeV D. Zschiesche et al. JPhysG 34, 1665 (2007)
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Isentropes, UrQMD and hydro evolution J. Steinheimer et al. PRC77, 034901 (2008) lines of constant entropy per baryon, i.e. perfect fluid expansion E/A = 5, 10, 40, 100, 160 GeV E/A = 160 GeV goes through endpoint
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P. Rau, J. Steinheimer, SWS, in preparation Including higher resonances explicitly Add resonances up to 2.2 GeV. Couple them like the lowest-lying baryons
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Include modified distribution functions for quarks/antiquarks Following the parametrization used in PNJL calculations The switch between the degrees of freedom is triggered by excluded volume corrections thermodynamically consistent - D. H. Rischke et al., Z. Phys. C 51, 485 (1991) J. Cleymans et al., Phys. Scripta 84, 277 (1993) U = - ½ a(T) ΦΦ* + b(T) ln[1 – 6 ΦΦ* + 4 (ΦΦ*) 3 – 3 (ΦΦ*) 2 ] a(T) = a 0 T 4 + a 1 T 0 T 3 + a 2 T 0 2 T 2, b(T) = b 3 T 0 3 T χ = χ o (1 - ΦΦ* /2) V q = 0 V h = v V m = v / 8 µ i = µ i – v i P ~ different approach – hadrons, quarks, Polyakov loop and excluded volume e = e / (1+ Σ v i ρ i ) ~~ Steinheimer,SWS,Stöcker hep-ph/1009.5239 * *
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quark, meson, baryon densities at µ = 0 natural mixed phase, quarks dominate beyond 1.5 T c densities of baryon, mesons and quarks Energy density and pressure compared to lattice simulations ρ
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Interaction measure e – 3p Temperature dependence of chiral condensate and Polaykov loop at µ = 0 lattice data taken from Bazavov et al. PRD 80, 014504 (2009) speed of sound shows a pronounced dip around T c !
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Lattice comparison of expansion coefficients as function of T expansion coefficients lattice data from Cheng et al., PRD 79, 074505 (2009) lattice results Steinheimer,SWS,Stöcker hep-ph:1009.5239 suppression factor peaks
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Φ Dependence of chiral condensate on µ, T Lines mark maximum in T derivative σ Separate transitions in scalar field and Polyakov loop variable
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Φ Dependence of Polyakov loop on µ, T Lines mark maximum in T derivative Separate transitions in scalar field and Polyakov loop variable σ
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Susceptibilitiy c 2 in PNJL and QHM for different quark vector interactions Steinheimer,SWS, hepph/1005.1176 g qω = g nω /3 g qω = 0 PNJL QH At least for µ = 0 – small quark vector repulsion
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σ Φ
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UrQMD/Hydro hybrid simulation of a Pb-Pb collision at 40 GeV/A red regions show the areas dominated by quarks
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SUMMARY general hadronic model as starting point works well with basic vacuum properties, nuclear matter, nuclei, … phase diagram with critical end point via resonances implement EOS in combined molecular dynamics/ hydro simulations quarks included using effective deconfinement field implementing excluded volume term, natural switch of d.o.f. If you want to do some lattice/quark calcs, grab your iPhone -> Physics to Go! Part 3
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order parameter of the phase transition confined phase deconfined phase effective potential for Polyakov loop, fit to lattice data quarks couple to mean fields via g σ, g ω connect hadronic and quark degrees of freedom minimize grand canonical potential baryonic and quark mass shift δ m B ~ f(Φ) δ m q ~ f(1-Φ) V. Dexheimer, SWS, PRC 81 045201 (2010) Ratti et al. PRD 73 014019 (2006) Fukushima, PLB 591, 277 (2004) U = ½ a(T) ΦΦ* + b(T) ln[1 – 6 ΦΦ* + 4 (ΦΦ*) 3 – 3 (ΦΦ*) 2 ] a(T) = a 0 T 4 + a 1 µ 4 + a 2 µ 2 T 2 q q
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hybrid hadron-quark model critical endpoint tuned to lattice results Phase Diagram for HQM model µ c = 360 MeV T c = 166 MeV µ c. = 1370 MeV ρ c ~ 4 ρ o V. Dexheimer, SWS, PRC 81 045201 (2010)
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C s ph ~ ¼ C s,ideal isentropic expansion overlap initial conditions E lab = 5, 10, 40, 100, 160 AGeV averaged C s significantly higher than 0.2
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important reality check compressibility ~ 223 MeV asymmetry energy ~ 31.9 MeV equation of state E/A ( ) asymmetry energy E/A ( p - n ) nuclear matter properties at saturation density binding energy E/A ~ -15.2 MeV saturation ( B ) 0 ~.16/fm 3 phenomenology: 200 - 250 MeV 30 - 35 MeV + good description of finite nuclei / hypernuclei SWS, Phys. Rev. C66, 064310
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subtracted condensate and polyakov loop different lattice groups and actions From Borsanyi et al., arxiv:1005:3508 [hep-lat]
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fsfs If you want it exotic … follow star calcs by J. Schaffner et al., PRL89, 171101 (2002) E/A-m N additional coupling g 2 of hyperons to strange scalar field g 2 = 0 g 2 = 2 g 2 = 4 g 2 = 6 barrier at f s ~ 0.4 – 0.6 0 0.5 1 1.5 0 100 200 300 simple time evolution including π, K evaporation (E/A = 40 GeV) C. Greiner et al., PRD38, 2797 (1988) with evaporation
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Temperature distribution from UrQMD simulation as initial state for (3d+1) hydro calculation dip in c s is smeared out Speed of sound - (weighted) average over space-time evolution initial temperature distribution
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Hypernuclei - single-particle energies Model and experiment agree well Nuclear matter
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Evolution of the collision system E lab ≈ 5-10 AGeV sufficient to overshoot phase border, 100-160 AGeV around endpoint
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amount of volume scanning the critical endpoint (lattice)
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Mass-radius relation using Maxwell/Gibbs construction Gibbs construction allows for quarks in the neutron star mixed phase in the inner 2 km core of the star V. Dexheimer, SWS, PRC 81 045201 (2010) R. Negreiros, V. Dexheimer, SWS, PRC, astro- ph:1006.0380
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