J/ΨProductioninHeavyIonCollisions

PengfeiZHUANGTsinghuaUniversity,BeijingIntroductionJ/ΨatSPSJ/ΨatRHICJ/ΨatNICA1RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009J/ΨProductioninHeavyIo●producedonlyintheinitialimpact,andnoextraproductioninthelaterevolution

aprobeofearlythermalizationandaprobeofQGP

●producedviahardprocess

rathersolidground

importanceofheavyquarksB.Mueller,nucl-th/0404015MatsuiandSatz1986:J/ΨsuppressionasasignatureofQGPformationinHI2RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009●producedonlyintheinitial●bothinitialproductionandregeneration

●bothnormalsuppressionandanomaloussuppression

J/Ψmotioninheavyioncollisionhotnuclearmattereffectscoldnuclearmattereffects3RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009●bothinitialproductionandJ/ΨatSPS:normalsuppressionmechanism:multi-scatteringbetweenJ/ΨandspectatornucleonsR.Vogt,Phys.Rept.310,197(1999)C.Gerschel,J.Hufner,Annu.Rev.Nucl.Part.Sci.49,225(1999)conclusion:

nuclearabsorptioncanwellexplaintheJ/Ψyieldinp-AandlightnuclearcollisionsatSPSenergy!NA384RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009J/ΨatSPS:normalsuppressiomodel1:Debyescreening(Matsui&Satz,1986)NA38atT=0atT≠0J/ΨatSPS:anomaloussuppressionmodel2:thresholdmodel(Blaizot,Dinh,Ollitrault,2000)model3:comoverinteractionCapella,Feireiro,Kaidalov,2000)5RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009model1:Debyescreening(MatsJ/ΨatRHIC:regenerationthereareabout10pairsofcquarksinacentralAu-AucollisionatRHICenergyandmorethan100pairsatLHCenergy

importantJ/Ψregenerationathighenergies:inQGPinhadrongasthecompetitionbetweenJ/\psisuppressionandregenerationleadstothequestion:J/Ψsuppressionorenhancementathighenergies?model1:statisticalproductionatTc,noinitialproduction

Andronic,PBM,Redlich,Stachel,2007mesonsmodel2:continuousproductioninsideQGPwithanomaloussuppression,noinitialproduction

Thews,Mangano,2006model3:two-componentmodel,initialproduction+regenerationGrandchamp,Rapp,Brown,2004regenerationinhadrongasisimportanttooBratkovskaya,Cassing,Stoecker,2003

thecompetitionbetweensuppressionandregenerationexplainswellthedata

6RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009J/ΨatRHIC:regenerationthereJ/ΨatRHIC:isregenerationnecessary?IJ/Ψpuzzle1:

almostthesamesuppressionatSPSandRHIC!Kaczmareketal.,2003explanationwithoutregeneration:Schroedingerequationforccbarwithlatticepotentialgivesthecharmoniumdissociationtemperature:

Karsch,Kharzeev,Satz,2006ifTSPS<TRHIC<TJ/Ψ,thesuppressionatSPSandRHICwillbethesameanditexplainsthepuzzle1.itlooksnotnecessarytointroducetheregeneration.explanationwithregeneration:

atRHIC,strongersuppressionandstrongerregeneration

7RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009J/ΨatRHIC:isregenerationnJ/ΨatRHIC:isregenerationnecessary?IIJ/Ψpuzzle2:strongersuppressionatforwardrapidity!explanationwithregeneration:strongerregenerationatmidrapidityLiu,Xu,Zhuang,2009

mid-rapidityforwardrapidityexplanationwithouthotnuclearmattereffects:differentJ/ΨproductioninpAandAAfromppKharzeev,Levin,Nardi,Tuchin,2009

strongJ/ΨsuppressionevenatT=0!8RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009J/ΨatRHIC:isregenerationntransportmodel(Hufner,Zhuang,2003;Zhu,Xu,Zhuang,2005):transportequationforJΨandhydrodynamicsforQGP

forJ/Ψyield,almostallthemodels–withandwithouttheassumptionofQGPandwithandwithoutregenerationmechanism–describetheobservedsuppression,afteratleastoneparameterisadjusted.

thetransversemomentumdistributionwhichdependsmoredirectlyontheproductionandsuppressionmechanismscontainsmoreinformationonthenatureofthemediumandJ/Ψandmayhelptodistinguishbetweendifferentscenarios.

J/ΨatSPS:transversemomentumsuppressionregenerationnoregenerationatSPSveryimportantleakageeffect!ptenhancementatSPS9RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009transportmodel(Hufner,ZhuanJ/ΨatRHIC:transversemomentumYan,Xu,Zhuang,2006;Liu,Xu,Zhuang,2009

lowptiscontrolledbybothinitialproductionandregenerationhighptenhancementisinducedbyCronineffectininitialproductioninitialproduction+regenerationexplainboththeyieldandtransversemomentumdistributionptbroadeningptsuppressionstrongptsuppression10RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009J/ΨatRHIC:transversemomen●LHC:almostonlyregeneration,sensitivetohotnuclearmatterRHIC:

bothinitialproductionandregenerationthecalculationneedsaquiteaccuratefine-tuningbetweenthetwoproductionmechanisms

SPS:

almostonlyinitialproductionNICA:onlyinitialproduction,sensitivetocoldnuclearmatter

J/ΨatNICA:coldnuclearmattereffects●istherapiditydependenceatNICAsimilartothatatRHIC?

2gluonfusionmechanism:no3gluonfusionmechanism:yes(Kharzeevetal.,2009)therapiditydependencecandistinguishfromtheinitialproductionmechanisms

●normalvsanomaloussuppressionatNICA

longercollisiontime(~1fm),important(dominant)nuclearabsorption,shorterlifetimeofhotmatter,weakeranomaloussuppression11RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009●LHC:almostonlyregenerat●ptdistributionatNICA

LHC:strongptsuppressionduetothermalizedregeneration

NICA:strongptenhancementduetoCronineffect(gluonmultiscattering)andleakageeffect(highmomentumparticlescanescapethehotmedium).thelifetimeofhotmatterisshortatNICAbutlongatRHICandLHC,theleakageeffectisthereforemoreimportantatNICA.J/ΨatNICA:others●mixedphaseatNICAthephasetransitionatNICAmaybeoffirstorder

lifetimeofmixedphasefractionofanomaloussuppressionRHIC4.5fm7%SPS5fm30%longlifetimeofmixedphaseandshortlifetimeofquarkmatter

thesuppressioninthemixedphasebecomesmoreimportantatNICA!12RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009●ptdistributionatNICAJ/Ψaconclusion

coldandhotnuclearmatereffectsonJ/Ψinhighenergynuclearcollisionsarestillnotclear

atNICA:1)

TransversemomentumandrapiditydistributionscandistinguishfromJ/Ψproductionmechanisms:

*ptenhancementduetoCronineffectandstrongleakageeffect*strongersuppressionatforwardrapidity(3gluonfusion)oratmidrapidity(2gluonfusion)?

2)NuclearabsorptiondominatestheJ/Ψsuppressionandanomaloussuppressionhappensmainlyinthemixedphase3)non-thermalizedJ/Ψhassmall(zero)ellipticflow.

13RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009conclusioncoldandhotnuthanksforyourattention14RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009thanksforyourattention14RoucentralitydependenceatSPSZhu,Zhuang,PRC67,067901(2003)

J/psiR_AAand<p_t^2>atSPSenergyasfunctionsofcentralityandp_tcanbewelldescribedbynuclearandmediumabsorption,withoutregeneration.15RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009centralitydependenceatSPSZhdominantregenerationatLHCwhileinitialproductionandregenerationareequallyimportantatRHIC,theJ/psiyieldatLHCischaracterizedbytheregenerationonly!*J/psiiscontrolledbyregeneration*J/psiyieldatLHCincreaseswithcentrality

Liu,Xu,Zhuang,PLB,2009andQM200916RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009dominantregenerationatLHCwhinitialproduction&nuclearabsorptionareincludedininitialcondition17RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009initialproduction&nuclearanearsidecorrelationinsQGPwetakedragcoefficienttobeaparametercharacteringthecouplingstrength*cquarkmotioninQGP:*QGPevolution:idealhydrodynamicsforstronglyinteractingquark-gluonplasma:●atRHIC,theback-to-backcorrelationiswashedout.●atLHC,cquarksarefastthermalized,thestrongflowpushtheDandDbartothenearside!

Zhu,Xu,Zhuang,PRL100,152301(2008)largedragparameterisconfirmedbyR_AAandv_2ofnon-photonicelectrons

(PHENEX,2007;MooreandTeaney,2005;Horowitz,Gyulassy,2007).

18RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009nearsidecorrelationJ/ΨProductioninHeavyIonCollisions

PengfeiZHUANGTsinghuaUniversity,BeijingIntroductionJ/ΨatSPSJ/ΨatRHICJ/ΨatNICA19RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009J/ΨProductioninHeavyIo●producedonlyintheinitialimpact,andnoextraproductioninthelaterevolution

aprobeofearlythermalizationandaprobeofQGP

●producedviahardprocess

rathersolidground

importanceofheavyquarksB.Mueller,nucl-th/0404015MatsuiandSatz1986:J/ΨsuppressionasasignatureofQGPformationinHI20RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009●producedonlyintheinitial●bothinitialproductionandregeneration

●bothnormalsuppressionandanomaloussuppression

J/Ψmotioninheavyioncollisionhotnuclearmattereffectscoldnuclearmattereffects21RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009●bothinitialproductionandJ/ΨatSPS:normalsuppressionmechanism:multi-scatteringbetweenJ/ΨandspectatornucleonsR.Vogt,Phys.Rept.310,197(1999)C.Gerschel,J.Hufner,Annu.Rev.Nucl.Part.Sci.49,225(1999)conclusion:

nuclearabsorptioncanwellexplaintheJ/Ψyieldinp-AandlightnuclearcollisionsatSPSenergy!NA3822RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009J/ΨatSPS:normalsuppressiomodel1:Debyescreening(Matsui&Satz,1986)NA38atT=0atT≠0J/ΨatSPS:anomaloussuppressionmodel2:thresholdmodel(Blaizot,Dinh,Ollitrault,2000)model3:comoverinteractionCapella,Feireiro,Kaidalov,2000)23RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009model1:Debyescreening(MatsJ/ΨatRHIC:regenerationthereareabout10pairsofcquarksinacentralAu-AucollisionatRHICenergyandmorethan100pairsatLHCenergy

importantJ/Ψregenerationathighenergies:inQGPinhadrongasthecompetitionbetweenJ/\psisuppressionandregenerationleadstothequestion:J/Ψsuppressionorenhancementathighenergies?model1:statisticalproductionatTc,noinitialproduction

Andronic,PBM,Redlich,Stachel,2007mesonsmodel2:continuousproductioninsideQGPwithanomaloussuppression,noinitialproduction

Thews,Mangano,2006model3:two-componentmodel,initialproduction+regenerationGrandchamp,Rapp,Brown,2004regenerationinhadrongasisimportanttooBratkovskaya,Cassing,Stoecker,2003

thecompetitionbetweensuppressionandregenerationexplainswellthedata

24RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009J/ΨatRHIC:regenerationthereJ/ΨatRHIC:isregenerationnecessary?IJ/Ψpuzzle1:

almostthesamesuppressionatSPSandRHIC!Kaczmareketal.,2003explanationwithoutregeneration:Schroedingerequationforccbarwithlatticepotentialgivesthecharmoniumdissociationtemperature:

Karsch,Kharzeev,Satz,2006ifTSPS<TRHIC<TJ/Ψ,thesuppressionatSPSandRHICwillbethesameanditexplainsthepuzzle1.itlooksnotnecessarytointroducetheregeneration.explanationwithregeneration:

atRHIC,strongersuppressionandstrongerregeneration

25RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009J/ΨatRHIC:isregenerationnJ/ΨatRHIC:isregenerationnecessary?IIJ/Ψpuzzle2:strongersuppressionatforwardrapidity!explanationwithregeneration:strongerregenerationatmidrapidityLiu,Xu,Zhuang,2009

mid-rapidityforwardrapidityexplanationwithouthotnuclearmattereffects:differentJ/ΨproductioninpAandAAfromppKharzeev,Levin,Nardi,Tuchin,2009

strongJ/ΨsuppressionevenatT=0!26RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009J/ΨatRHIC:isregenerationntransportmodel(Hufner,Zhuang,2003;Zhu,Xu,Zhuang,2005):transportequationforJΨandhydrodynamicsforQGP

forJ/Ψyield,almostallthemodels–withandwithouttheassumptionofQGPandwithandwithoutregenerationmechanism–describetheobservedsuppression,afteratleastoneparameterisadjusted.

thetransversemomentumdistributionwhichdependsmoredirectlyontheproductionandsuppressionmechanismscontainsmoreinformationonthenatureofthemediumandJ/Ψandmayhelptodistinguishbetweendifferentscenarios.

J/ΨatSPS:transversemomentumsuppressionregenerationnoregenerationatSPSveryimportantleakageeffect!ptenhancementatSPS27RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009transportmodel(Hufner,ZhuanJ/ΨatRHIC:transversemomentumYan,Xu,Zhuang,2006;Liu,Xu,Zhuang,2009

lowptiscontrolledbybothinitialproductionandregenerationhighptenhancementisinducedbyCronineffectininitialproductioninitialproduction+regenerationexplainboththeyieldandtransversemomentumdistributionptbroadeningptsuppressionstrongptsuppression28RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009J/ΨatRHIC:transversemomen●LHC:almostonlyregeneration,sensitivetohotnuclearmatterRHIC:

bothinitialproductionandregenerationthecalculationneedsaquiteaccuratefine-tuningbetweenthetwoproductionmechanisms

SPS:

almostonlyinitialproductionNICA:onlyinitialproduction,sensitivetocoldnuclearmatter

J/ΨatNICA:coldnuclearmattereffects●istherapiditydependenceatNICAsimilartothatatRHIC?

2gluonfusionmechanism:no3gluonfusionmechanism:yes(Kharzeevetal.,2009)therapiditydependencecandistinguishfromtheinitialproductionmechanisms

●normalvsanomaloussuppressionatNICA

longercollisiontime(~1fm),important(dominant)nuclearabsorption,shorterlifetimeofhotmatter,weakeranomaloussuppression29RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009●LHC:almostonlyregenerat●ptdistributionatNICA

LHC:strongptsuppressionduetothermalizedregeneration

NICA:strongptenhancementduetoCronineffect(gluonmultiscattering)andleakageeffect(highmomentumparticlescanescapethehotmedium).thelifetimeofhotmatterisshortatNICAbutlongatRHICandLHC,theleakageeffectisthereforemoreimportantatNICA.J/ΨatNICA:others●mixedphaseatNICAthephasetransitionatNICAmaybeoffirstorder

lifetimeofmixedphasefractionofanomaloussuppressionRHIC4.5fm7%SPS5fm30%longlifetimeofmixedphaseandshortlifetimeofquarkmatter

thesuppressioninthemixedphasebecomesmoreimportantatNICA!30RoundTableWorkshoponNICAPhysicsDubna,September9-12,2009●ptdistributionatNICAJ/Ψaconclusion

coldandhotnuclearmatereffectsonJ/Ψinhighenergynuclearcollisionsarestillnotclear

atNICA:1)

TransversemomentumandrapiditydistributionscandistinguishfromJ/Ψproductionmechanisms:

*ptenhancementduetoCro