从双轻子产生探测致密物质状态方程

Di-leptonproductionasprobe

todensematterEOS

从双轻子产生探测致密物质状态方程JianDeng(邓建)Departmentofmodernphysics,USTCwithQ.Wang,

N.Xu,

P.-fZhuang2009-11-7@USTC第十三届中高能核物理大会BackgroundandMotivationHydrodynamicsforHICDi-leptonspectraafterevolutionSensitivitytoEOSSummaryandconclusionBackgroundDenseorhot

QCDmatterProperty?Transition?Electromagneticprobeforearlyuniverse

1.Chiralsymmetryrestoration2.Electromagneticprobetohot/densemedium3.Space-timeevolutionoffireballDi-leptoninvariantmassspectraSlopeparameterT-eff(MeV)Thetransitiontoalow-flowregionmaysignalatransitionfromahadronicsourcetoapartonicsourceNA60,PRL100,022302(2008)EffectivetemperatureHeavyIonCollisionsHICS.BassHadronizationandFreeze-outInitialconditionsInitialconditioninhigh-energynuclearcollisions-ColorGlassCondensationCold-QCD-matter,small-x,high-partondensity -partonstructuresinnucleon/nucleusPartonicmatter-QGP-Thehot-QCDInitialhighQ2

interactionsHardscatteringproduction-QCDpredictionInteractionswithmedium-deconfinement/thermalizationInitialpartondensityByRichard.Heeks;From:/photos/11164709@N06/sets/72157607182199900/

HydrodynamicsDescriptionAssuming(thermalization,Ideal?Viscous?)Input(EOS,initialcondition,Freeze-outcriteria)Output(space-timeevolution)Comparingwithexp.(T_f,v,v2…)Following(fluctuation,correlation,newstatistic)References:Baym86',Rischke98',Kolb&Heinz,00',manyothers...BasicforhydrodynamicsLocalconservationofnetchargeandenergy-momentum4+1equations,tosolve10+4functionsIdealHydrodynamics+EOS

Foridealgasinequilibrium4+1equations,5+1unknownfunctions+EOSEOSasaninputtodefinetherelationbetweenenergydensity,pressureandtemperatureScalingandInitializationLandauModelvsBjorkenModelGlauberModelvsCGCBjorkenModelFreeze-outandrapidityplatformCooper-FryeformulaRapidityindependenceEllipticflow25--30%P.&U.RomatschkePRL07IdealVSViscousDi-leptonproductioninHICDrell-Yanprocessatpre-equilibriumCharmoniumandopencharmThermalquarkanti-quarkannihilationatQGPThermalpionannihilationathadronicphaseVectormesons,Dalitzdecay,4-pionprocess……Di-leptonemittedinthefireball,notfromthesurfaceHowtocalculateEmissionradiationinthermalbath:MasslessfreeQGPHadrongasMixphaseLatticeEquationOfStateFreeQGPLatticeYieldasfunctionofpropertimeEOSdependenceofyieldFreeQGPHadrongasMixphaseLatticeInvariantmassdistributionFreeQGPHadrongasMixphaseLatticeTwostageofevolution.M<1GeV:RHG.M>1GeV:QGP.SlopeparameterreflectsthetemperatureandvelocityofthethermalsourceP_Tslope:EffectivetemperatureEOSdependenceofslopeparameterFreeQGPHadrongasMixphaseLatticeEffectfromT_cshiftLowerTc,smallerRHGcontribution,fastervelocityatoutercoronal;LesseffecttoQGPemission;Tc180->150makesthedeclinemoredistinguishableonlyRHGonlyQGPTc=150MevTc=180MevEffectfrominitialconditionshifttau_0=0.6fm,T_0=350Mevtau_0=0.2fm,T_0=520MevNosignificantdifference,except:

loweffectivetemperaturewithcoolerinitialconditionmoreobviousdeclineifinitializelaterEOSdependenceofv2(M,PT)FreeQGPHadrongasMixphaseLatticeEOSdependenceofv2(M)FreeQGPHadrongasMixphaseLatticeIfemissionfromsurfaceNostructuretomanifestthephasetransitionSummaryandConclusionIdealHydrodynamicsisusedtodescribethespace-timeevolutionofHIC.Differentdi-leptonemissionprocessinQGPandRHGareconsidered.Di-leptonspectrafromdifferentEOShavedistinctdifferen