Ph-Ddefense国外博士论文答辩PPT

1,IdentifiedParticleProductioninp+pandd+AuCollisionsatRHICEnergies,FelixMatathiasDoctoralDefenseAdviser:TomHemmickStateUniversityofNewYorkatStonyBrook,December8,2004,NewYork,2,ComparativeNuclearPhysics,Yesterdayitoccurredtomethatthecoreconceptofmythesisisnotsodifferentthanwhatmywifedoesforaliving.MywifeisaPh.D.studentinComparativeLiteratureatStonyBrook.Igaveheracalllastnightandaskedherforashortdefinitionofherfield.SherepeatedlyaskedmywhyIneededitandseemedconfused(andconcerned).ThegoalofComparativeLiteratureis:“tocompareliteratureindifferentlanguagesandliteraturewithrelationtosomeotherfield”Inthatvein,IdefinethegoalofComparativeNuclearPhysicstobe:“comparepropertiesofparticleproductionindifferentnuclearenvironmentsandasafunctionofparticleflavor”ObviouslythisisanarrowdefinitionthatImadeuptodefinethegoalofmythesis.Itcouldeasilythoughbeextendedtoamoregeneraldefinition.ThemainpointthoughisthatmywifemaybecomeinterestedinwhatIdo.,3,ComparativeNuclearPhysicsII,InthisworkwewillbecomparingparticleproductionatCenterofMassEnergy:s=200GeVDifferentnuclearenvironments:p+pcollisionsd+AucollisionsAu+AucollisionsParticlespecies:pions,Kaons,(anti)protonsThephysicalobservableswillbeDifferentialyieldperinelasticcollisioninthed+AuandAu+AucaseInvariantdifferentialcrosssectionsinthep+pcase,4,Themachine,RelativisticHeavyIonColliderBrookhavenNationalLab2counter-circulatingrings3.834kmcircumferenceSuperconductingmagnets(3.5T)192dipolesperring246quadrupolesperringTimebetweencollisions:0.213microsecondsCrossingangle:0Bunchlength:20cmBunchesperring:56Luminositylifetime:3-10hoursParticlesperbunch(units1010):Au+Au:0.1p+p:10Topenergies(eachbeam):100GeV/nucleonAu+Au.100GeV/nucleond+Au100GeVpolarizedp+p,5,Thedetector,MaximalSetofObservablesPhotons,Electrons,Muons,ID-hadronsHighlySelectiveTriggeringHighRateCapability.RareProcesses.Butrareprocessesalwayscomelateinthegameforcolliderexperimentsduetolimitedluminosity.ButIwantedathesisatsomepoint.ThereforeIutilizethecopiousproductionofhadrons,throughthestrongnuclearforce,albeitwitharelativelysmalldetector.,6,Doesnuclearsizematter?(Yes,butinmysteriousways),ComparingparticleproductionindifferentnuclearenvironmentswouldntbethatinterestingifeverythingscaledaccordingtothesizeofthecollidingsystemDefinitionofpoint-likescaling:.Dowealreadyknowanythingaboutthescalingpropertiesofhardscattering?Answer:Yes,weknowthatscalingisstronglyviolated!,7,ColdNuclearMatterEffects:the“InitialState”,8,CroninEffect,Inp+Acollisions:ParameterizationdonebyCroninetal.(Phys.Rev.D11,3105,1975)Alphafactorsare:pt-dependentspecies-dependentCronineffectEnhancementathigh-ptShadowingatlow-ptMechanism:Initialpartonmultiplescattering,Antreasyanet.al.Phys.Rev.D19(3)1979,Straubet.alPhys.Rev.Lett.68(4)1992,Questionsthatthisthesiswillanswer:WhatisthesizeoftheCronineffectatRHICenergies?Whatisthespecies-dependenceoftheCronineffectatRHICenergies?WhatistheenergydependenceoftheCronineffectatRHICenergiescomparedtoFermilabobservations?,9,PartonSaturation,Linearevolution(DGLAP)leadstoviolationofunitarity.Atsomepoint,thepartondensityacquiresanegativeterm:,10,Theonsetofpartonsaturation,“Packing”factor,Onsetofsaturation:k1Solutioninthex-Qplane.,Saturationmoment:Thescaleatwhichnon-lineareffectsstarttobeimportantinthehadronwavefunction.,ForQQ_saturation(t)non-lineareffectsarenegligibleandlinearevolutioneffectsapply(BFKL,DGLAP),11,Theneteffectofpartonsaturationisparticlesuppression.,d,A,Saturatednuclearwavefunction,Non-saturateddeuteronwavefunction,“Cronin”,“Suppressed”,Thisthesisanswersthequestion:enhancementorsuppresionforidentifiedparticles?,Phys.Let.B561,93(2003),12,HotandDenseNuclearMatterEffects:theFinalState,13,Anewstateofmatter,Hypothesis:hadronicmatterundergoesaphasetransitionastemperaturereachesT170MeVSupportedbythedecreaseofthestrongcouplingconstantasafunctionofenergy.Energydensityincreasesoveranorderofmagnitudeinanarrowrangeoftemperatures10-20MeVLatticeQCDprovidesthemostquantitavetheoreticalsupporttothisday.,F.Karsch,Lect.Notes.Phys583,209(2002),Understandingthetransitionasachangeofthenumberofdegreesoffreedom:,BelowTc:dilutegasof3statesofpions,AboveTc:for2flavorswehave,2(flavors)x2(quark,antiquark)x2(spinstates)x3(colors)=24quarkd.o.f.8(colorsofgluons)x2(helicityd.o.f.)=16gluonicd.o.f.,14,AnewStateofMatterII,ThequarkandgluondegreesoffreedomnormallyconfinedwithinhadronsaremostlyliberatedThetransitionoccurswhentheenergydensityofmatterisoftheorderofthatofmatterinsideaprotonEnergydensityaboutanorderofmagnitudelargerthantheenergydensityinsideatomicnuclei:1-10GeV/fm3,Wecandothis!Au+AucollisionsatRHICpushmatterattheseextremesroutinely.,15,Theobservableofthedayisagain.,Scenario1:RAA=1:Scalewith#ofbinarycollisions(Ncoll).Scenario2:RAA1:Cronineffect(observedinISRandSPS).Scenario3:RAA1:Suppression.,/sinelp+p,16,Suppressionofhighptparticles,CentralRAAsuppressedbyfactorof4.5,MediuminducedenergylossinsidethemediumPredominantlyviagluonbrehmstrahlungemmisionOr,partonsaturation?,Thisquestionisansweredinthisthesisforidentifiedparticles.,17,Butthereismoretoit.,Thesuppressionpatternseemstobestronglydependentonparticleflavor.Counterintuitive.Ifpartonsfromhardscatteringarelosingenergyinthemedium,shouldntthatreflecttoallparticlesproduced?,Ncollscalingatallcentralitiesfortheprotons.,Aquestionthatthisthesiswillanswer:CouldahigherCronineffectfortheprotonsexplainthiseffect?,Notice:R_CPnotR_AA,18,Furthermore.,Ananomalouslyhighprotontopionratiowasobserved.Aspectacularobservationthathadnotbeenpredicted.Lighterpionsarefavoredduetophasespacepopulation.Fragmentationfunctionsfromelementaryp+pande+ecollisionsseemtobechangedinsidethemedium.Whatistheextrasourceofprotons?,Aquestionthatthisthesiswillanswer:Whatarethevaluesoftheseratiosinelementaryp+pandd+Aucollisionsatthesameenergy?,19,BestofPIDAnalysisinp+pandd+Aucollisions.,20,ChargedHadronPIDAnalysis,DetectorsforhadronPIDDCH+PC1+TOF+BBCDf=p/8,-0.35h0.35MomentumResolutionTOFresolutionsTOF130ps.HadronPIDinm2vs.pspacewithasymmetricPIDcuts.0.2p3.0GeV/c,0.4K2.0GeV/c,0.6p3.7GeV/c.,21,PIDwithBBC+TOF+DCH:Timingcalilbrations,TimingCalibrations:SlatbySlatRunbyRunGlobaltimingoffsets,22,PIDwithBBC+TOF+DCH,Clearseparationofparticlesuptohighpt.Stableperformanceinp+pandd+Aucollisions,Thep+pandd+AudataarebothfromRHICRUN03andthereforedetectoreffectsaresmallinmostratiosofp+pandd+Audata.,23,PIDcuts,Widthofcuts3parametersimultaneousfittomasswidthsforallparticlesParameterizationofcutsinGaussianwidths,independentofmomentum,24,VerificationofPIDcutsparameterizations,25,Detectoracceptanceandefficiencycorrections,DetectoracceptancesisstudiedindetailHolesareremovedbycutsIndependentstudiesfor:Positive/negativeparticlesDCHandTOFdetectorsNorthandSouthsides,DetectorareasofmaximumefficiencyarecomparedtoMonteCarlosimulationandefficiencycorrectionsfortheentiredetectoristhencalculated.,26,Matchingandfiducialcuts,GoldenFiducialcuts,ResidualdistributionbetweenTOFhitandtrackmodelprojection.,Distributionsarefittedasafunctionofmomentumforpositive/negativeparticles,forNorth/Southpartofthedetector,27,DetectorStability:Excerpts,Antiproton/protonvs.RunNumber,PIDcutsvs.RunNumber,Numberoftracksvs.RunNumber,Acceptancevs.RunNumber,28,MonteCarloCorrections,SincePhenixdoesnotcoverfullacceptanceinphiandzedweuseMonteCarloSimulationtocorrectforgeometricalacceptance.Alsoinflightdecaysarecorrectedfor.FinallyallcutsusedinrealanalysisarealsousedinMonteCarloanalysisandthereforetheefficiencyofthecutsarethuscalculated,29,Systematicerrors,Systematicerrorevaluationisdonebyvaryingcutconditionsintheanalysisby1s,2s,etc.Additionalsystematicvariationsare:Run-by-runvariations5%Efficiencycorrections3%Feed-downcorrections10%InadditiontheBBCcrosssectionintroducesa10%systematicerroronp+pcrosssections.,TYPE-B:Momentumcorrelated,allpointsmoveinthesamedirectionbutnotbythesamefactor,TYPE-C:Momentumindependent,p+pType-C:,30,Feed-downcorrections,AsignificantfractionofprotonsandantiprotonsdetectedbytheTOForiginatefromweakdecaysof:HyperonsY(qqs)CascadesX(qss)OmegasW(sss)Sincetheweakdecaystakeplaceveryclosetothevertex,andsincetheheavierprotonstakemostofthedecaymomentum,thesetracksarevirtuallyindistinguishablefromtracksarisingfromthevertexofthecollision.,TotalprotonsdetectedbyTOF:,ParticlecompositionfromUA5in200GeVp+pbarcollisions,31,ee,InputLSpectrainp+pandd+AufrompreliminarySTARresultsandUA5,ConstructionofeffectiveLSpectrumwhichthenisdecayedinPHENIX,32,Feed-downcorrections,Correctionisoftheorderof30%forprotonsandantiprotons.UsingthepreliminaryAntilambda/Lambdaratio0.85+/-10%fromSTARweapplycorrespondingcorrectionstoprotonsandantiprotons.Largesystematicerroronthefeed-downprotonsarisesfromlargeUA5systematicsandpreliminaryStarresultsSystematicerror24%,33,Centralitydeterminationind+Au,Centralitydeterminationind+AuisdonewiththeSouthBBC(Au-side).Assumption:BBCsignalisproportionaltoparticipatingAunucleons.GlauberModelcalculationandBBCsimulationresponse,maptheBBCSsignaltoimpactparameterdistributions.CorrespondingNcolldistributionsind+Auarethenusedtodefinethenuclearmodificationfactors.,34,Results,35,I.Spectra,36,Pions,37,Kaons,38,Protons,39,d+AuMinBias,40,p+pinvariantcrosssections,41,II.Ratios,42,Antimatter/matterd+Au+Systematics,43,Antimatter/matter:p+p,44,Antimatter/matter:p+p,d+Au,45,Antimatter/matter:p+p,d+Au,Au+Auperipheral,46,Antimatter/matter:Allcollisionsystems,Withintheerrors,allratiosareflatandindependentofcollisionsystem!,Astonishingresultsincethemicroscopicmechanismforparticleproductioninp+pandcentralAu+Aucollisionsisfundamentallydifferent.,47,Nocentralitydependencewithind+Au,48,p/pinallsystems,Returnoftheratiotonormalvalues.SmoothtransitionfromcentraltoperipheralAu+Aucollisions.d+AuissimilartothemostperipheralAu+Aubin.p+pislowerthand+Au,duetolargeCroninforprotons,49,p/pinp+pandd+Au,Moderatecentralitydependenceind+Au.p+pcollisionsarelower.,50,III.NuclearModificationFactors,51,RdAuMinimumBias,Nosuppression.WeestablishthesizeofCronineffectatRHICenergies.SpeciesdependenceofCroninissignificant.Aswewillseeinthefollowing,CronineffectforprotonsisnotlargeenoughtojustifyAu+Aubehavior.Protons:40%enhancementPions:10%enhancement,52,RdAu00-20%,Stillaround10-15%enhancement,60%enhancement,53,RdAu20-40%,54,RdAu40-60%,55,RdAu60-90%,Binaryscalinginperipheralcollisions.,56,PionRCPfrom3differentdetectors:Cronineffectdissapearsathighpt,ChargedpionsfromTOF.NeutralpionsfromEMCAL.ChargedpionsfromRICH+EMCAL.Niceagreement.Cronineffectforpionssaturatesatpt8GeV/c,57,NuclearModificationfactorsinAu+Aucollisions.,58,RAuAuofidentifiedparticles:0-5%,59,RAuAu0-5%withneutralpions,60,RAuAu0-5%withneutralpions,Suppressedbyfactorof5,RAuAu1.25,Pionsuppressionbyafactorof6relativetotheprotons,SpeciesdependenceofCronineffectind+Aunotmorethan35%,61,RAuAuofidentifiedparticles:60-92%,62,RAuAu60-92%withneutralpions,63,Comparison:RAuAuvs.RdAu,64,EnergyDependence,UsingmodestassumptionswecancalculateRdAuatlowerenergies.Usethealpha-factorsmeasuredbyStraubetal.ComparewithRdAuatRHICenergies.,LowEnergyDatafrom:Phys.Rev.Lett.68452,1992,InclusiveChargedandNeutralPiondataprovethattheCronineffectfortheprotonsissignificantlyloweratRHICenergies.,65,OpposingTheoreticalModelsfortheCroninEffect,66,Accardi-GyulassyPhys.Lett.B586,244(2004),Glauber-Eikonalformalism.Calculationofseriesdirectlyvianumericalconvolutionofelementaryparton-nucleonprocesses.Parameters:p0=1.0GeV,infraredcutoff,establishedfromfittingp+pdataIntrinsic=0.52GeV2,establishedfromfittingp+pdataK=1Allrenormalizationscalessettomt/2Theoreticalerrorfromvaryingcut-offvalue.Noadditionalshadowingisaddedbyhand.,Ifthismechanismisbelowtheexperimentaldatathenpartonsaturationscenariosmaybeneededtoexplainthedata.,67,RdAu00-20%,Reasonableagreementwiththedata.Noneedforadditionalsaturationscenarios.Centralitydependenceisreproduced.ColorGlasspredictionfromKharzeev,LevinandMcLerranisalsoshown.Theoreticalcalculationbecomesunreliablebelowthecut-offvalue.,Phys.Let.B561,93(2003),68,RdAu20-40%,69,RdAu40-60%,70,RdAu60-90%,71,CroninEffectasaFinalStateInteractionEffect.RecombinationbyHwa&Yang,72,TheHwa-Yangprogram(OregonGroup),Clusteringandhadronizationofquarks:Atreatmentofthelow-ptproblemPhys.Rev.DVolume22,p.1593,1980PartonDistributionsintheValonModelhep-ph/0202140RecombinationModelforFragmentationhep-ph/0312271RecombinationofshowerpartonsathighptinHeavyIoncollisionsnucl-th/0401001FinalStateInteractionastheoriginofCronineffectnucl-th/0403001,73,RecombinationmodelforFragmentation,Ahardpartonwithhighvirtualityinitiatesapartonshowerthroughgluonradiationandpaircreation.Nonperturbativeprocess.Thefragmentationfunction(FF)canbewrittenintermsoftheshowerpartondistributions(SPD)andtherecombinationfunction(RF).UsethemeasuredFFs.SolvetheequationfortheSPDs.UsetheSPDsindifferentenvironments(d+Au,Au+Au).,74,RecombinationofShowerPartonsinHeavyIonCollisions:ThermalandShowercomponents,FirstapplicationofSPDoutsidetherealmofpartonfragmentation.Startwiththemesonproduction.Fixalltheparameters.Calculatetheprotonproduction.Deriveprotontopionratio.,75,ResultforpionsandprotonsinAu+Au.,Theprotonspectrumisreallyapredictionofthemodel.,76,Thenextstep:d+AuFinalStateInteractionastheOriginofCroninEffect.,Nobroadeningbysuccessivekicks.Noenergyloss.Thermal-Showerrecombinationisresponsiblefortheenhancementatintermediatept.Interactionbetweensoftandshowerpartons.Softcomponentisnotthepredictablepartofthemodel,requiresfittingtogetCandT.ThemagnitudeoftheTStermistheprediction.,77,RCPforpionsandhigherCroninforprotonsind+Au.,SpectraandRcpforpions.Protontermwillhave:TTT+TTS+TSS+SSS+FirstshotatexplainingthehigherCroninforbaryons.,78,FirstExplanationofCroninEffectforprotonsind+Au.,Goodagreementwiththed+Audata.,Thisradicalinterpretationofthedataintroducesareinterpretationofparticleproductionwithfarreachingconsequences.,Separationofpartonsintotwonon-interactingcomponents,softandhard,isanoversimplification.,PROTONPRODUCTIONIND+AUCOLLISIONSANDTHECRONINEFFECT.ByR.C.Hwa(OregonU.)andC.B.Yang(OregonU.andHua-ZhongNormalU.)Apr2004.4pp.PublishedinPhys.Rev.C70:037901,2004e-PrintArchive:nucl-th/0404066,79,ConclusionsandPerspective,WehaveestablishedtheinitialconditionsofidentifiedparticleproductionatRHICenergiesthroughadetailedstudyofp+pandd+Aucollisions.ThroughthesemeasurementsweconcludeontheoriginofsomeoftheanomalousresultsdiscoveredincentralAu+Aucollisions.InanutshellweprovedthatallthesespectaculareffectsareFINALSTATEEFFECTSandhavenothingtodowithinitialstateconditions.Wealsoperformedadetailedstudyofthecoldnuclearmattereffectsarisingfromd+Aucollisions.Furtherstudiesofjetpropertiesofidentifiedparticleswillshedmorelightintherealmicroscopicmechanismresponsibleforparticleproductioninhotanddensenuclearmatter.,80,TheFuture,Thed+Audatapresentedtodayaregoingtobepublishedintheupcomingweek.ApaperonComparativeNuclearPhysicsusingthep+p,d+AuandAu+Audataisalsounderway.Iamalsoinvolvedintheanalysisof62.4GeVAu+AucollisionsandIamamemberofthepaperpreparationcommittee.Asforme,afterthecompletionofthesepapers,Iwillofficiallyretirefromtheprofessionofidentifiedspectrologist.Iamnotsureyetwhatmynextobservableisgoingtobe.Mostprobablyitwillhavetodowithmoredetailedtestsoftherecombinationtheory.ForthenearfutureIwillbeworkingfortheDAQsystemofPHENIXasaColumb