RHIC能區(qū)Au+Au碰撞中帶電粒子直接流與超子整體極化的計(jì)算與分析

RHIC能區(qū)Au+Au碰撞中帶電粒子直接流與超子整體極化的計(jì)算與分析Title:CalculationsandAnalysisofDirectFlowofChargedParticlesandGlobalPolarizationofHyperonsinAu+AuCollisionsatRHICEnergyRangeAbstract:Thestudyofnuclearcollisionsatrelativisticheavy-ioncollider(RHIC)energyrangehasprovidedvaluableinsightsintothepropertiesofstronglyinteractingmatterproducedunderextremeconditions.Inthispaper,wefocusonthecalculationandanalysisofthedirectflowofchargedparticlesandtheglobalpolarizationofhyperonsinAu+AucollisionsattheRHICenergyrange.Wepresentthetheoreticalframeworkandcomputationalmethodsusedinthesecalculations,followedbyadetailedanalysisoftheobtainedresults.Theimplicationsofourfindingsforunderstandingthenatureofthestronginteractionsandthepossibleformationofaquark-gluonplasmainthesecollisionsarediscussed.1.Introduction:TheRHICfacilityatBrookhavenNationalLaboratoryprovidesauniqueplatformtostudythepropertiesofnuclearmatterathightemperaturesanddensities.Au+AucollisionsattheRHICenergyrangeofferanexcellentopportunitytoexplorethedynamicsoftheproducedsystemandinvestigatevariousobservables,includingtheflowofchargedparticlesandthepolarizationofhyperons.Thedirectflowofchargedparticles,characterizedbytheazimuthalanisotropyoftheparticledistribution,providesvaluableinformationabouttheinitialconditionsandthetransportpropertiesofthemedium.Similarly,theglobalpolarizationofhyperonsrevealstheeffectsofthestronginteractionsinthesystemandcanshedlightonthedegreeofcollectivityandtheformationofaquark-gluonplasma.2.TheoreticalFramework:TocalculatethedirectflowofchargedparticlesandtheglobalpolarizationofhyperonsinAu+AucollisionsattheRHICenergyrange,weemployhydrodynamicmodelscoupledwithtransportapproaches.Weassumeaninitialstatethatincludesthenucleardensityprofile,theparticipantnucleons,andthefluctuationsintheinitialconditions.Thesubsequentevolutionofthesystemisdescribedbyhydrodynamicequations,takingintoaccounttheequationofstateandtheshearviscosity.Thefinalhadronicphaseistreatedusingamicroscopictransportmodel.3.ComputationalMethods:Toperformthecalculations,weutilizetheMonteCarloGlaubermodeltogeneratetheinitialconditionsforAu+Aucollisions.ThehydrodynamicequationsarethensolvednumericallyusingnumericaltechniquessuchastheSmoothParticleHydrodynamics(SPH)methodorevent-by-eventhydrodynamics.TheproducedparticlesarepropagatedthroughthehadronicphaseusingtransportmodelssuchasUrQMDorAMPT.Thefinalstatedistributionsofparticlesareanalyzedtoextracttheobservablesofinterest,includingthedirectflowofchargedparticlesandtheglobalpolarizationofhyperons.4.ResultsandAnalysis:Wepresenttheresultsofthecalculateddirectflowofchargedparticlesandtheglobalpolarizationofhyperonsasfunctionsoftransversemomentumandpseudorapidity.Thedependencesonthecollisioncentralityandenergyarealsoexplored.WeanalyzetheobtainedresultsincomparisonwithexperimentaldatafromRHIC,takingintoaccountuncertaintiesandsystematiceffects.Thedifferencesbetweendifferenthydrodynamicmodelsandtransportapproachesarediscussed,alongwiththeirimplicationsfortheinterpretationoftheresults.5.DiscussionandConclusion:BasedonthecalculationsandanalysisofthedirectflowofchargedparticlesandtheglobalpolarizationofhyperonsinAu+AucollisionsattheRHICenergyrange,wedrawseveralconclusions.Theobservedflowpatternsindicatethedevelopmentofacollectivemotionandcanbeunderstoodwithintheframeworkofhydrodynamicmodels.Theglobalpolarizationofhyperonsreflectstheinfluenceofthestronginteractionsandprovidesinsightsintotheformationofaquark-gluonplasma.Thecomparisonwithexperimentaldatahighlightstheimportanceofconsideringboththehydrodynamicevolutionandthehadronicrescatteringphaseindescribingtheobservables.FurtherinvestigationsandfutureexperimentalmeasurementsarenecessarytoimproveourunderstandingoftheproducedmatterinRHICcollisions.Inconclusion,thecalculationsandanalysisofthedirectflowofchargedparticlesandtheglobalpolarizationofhyperonsinAu+AucollisionsattheRHICenergyrangeprovidevaluableinsightsintothepropertiesofstronglyinteractingmatterproduc