230 likes | 345 Views
Time evolution of QGP via photon observables. Presenter : Imre Májer – Eötvös University Physics student Supervisor : Máté Csanád – Department of Atomic Physics. Zimányi Winter School 2011. Rhic milestones. New, strongly interacting medium ( Nucl.Phys ., A757:184–283, 2005 )
E N D
Time evolution of QGP via photon observables Presenter: Imre Májer – Eötvös University Physicsstudent Supervisor: Máté Csanád – Department of AtomicPhysics Zimányi Winter School 2011
Rhicmilestones • New, stronglyinteractingmedium (Nucl.Phys., A757:184–283, 2005) • Collectivebehaviour (Phys.Rev.Lett., 91:182301, 2003) • Perfect fluid hydro (Phys.Rev.Lett., 98:172301, 2007) • Quarkdegrees of freedom (Phys.Rev.Lett. 98, 162301,2007) • Directphotondata, timeevolutioncan be analyzed (Phys.Rev.Lett., 104:132301, 2010)
Time development - Spectra thermalization
Spectrainformation Physical quantitieswecangetfromdifferentspectra: • Hadronicspectra • Freeze-outtemperature () • Freeze-outtime () • Freeze-outexpansionvelocities (, , , , ) • Photonspectra • Equation of state () • Thermalizationtime () • Initialtemperature ()
PhysicalQuantities Howdowegetthephysicalquantitiesdescribingthesystem?
The probability of particlecreationat a givenplace and timewith a given momentum: • Photons: bosonsBose-Einsteindistribution – Cooper-Fryefactorgivestheintegrationmeasure • Integratethesourcefunction: invariant momentum distribution One of the most importantobservable!
Relativistic hydroforperfectfluids: • Equation of state () • Assuming an avarage constant • Idealsolution: • Relativistic • 1+3 dimensional • Realistic (eg. ellipsoidal) geometry • AnisotropicHubble-flow ( const.)aftersometime • Acceleratingatthe start of thetimedevelopment
The examinedsolution (Csörgő et al., 2004): • Relativistic, 1+3 dimensional • Scalingparameter – ellipsoidalsymmetry: • Arbitraryfunction of thescalingparameter: is thegoodtemperaturegradient • Hubble-flow: • Non-accelerating:
3.Observables – rapidity () 3D: 2D: Fourier series of theazimuthaldistributionfunction InverseFourier-transformtransverse momentum distributionand elliptic flow Bose-Einsteincorrelation: correlationradii (HBT radii)
Fixed byhadronspectrum fit: (M. Csanád – M. Vargyas: Eur.Phys.J., A44:473–478, 2010.) Properties of the fit:
Photon momentum distribution Fitting to0-92% centrality PHENIX data: EoSfromphotonspectra:
QGP initialtemperature With and , hydrogivesustheinitialtemperature: Determinedfromphotonspectra Fixed fromhadronicobservables
Photonelliptic flow Ellipticflow from PHENIX data [arXiv:1105.4126]: • Many models fail • Non-hydro effects from2 GeV • Sign change possible
Bose-Einsteincorrelation HBT radiiatfreeze-outtime (): • Rout/Rside = 1 for hadrons • RoutRside here, differenttimeevolution!
Furtheranalysis Other microscopicmodels: additionalscalingwith needed with (orifvelocity is temperaturedependent) Ourmodelalready Examined with use ofadditional minor change, systematic error N=0 N=2 N=1 N=3
Summary • 1+3D realisticrelativistichydromodelwithoutacceleration • Calculated, and HBT radiiforphotonsource • Fitted withfreeze-outparameters fixed byhadronsolution • Importantnewparameters: EoSand initialtemperature: MeV • Correspondstoothertheories(R. A. Lacey, A. Taranenko., PoS, CFRNC2006:021, 2006: ; A. Adare et al., Phys.Rev.Lett., 104:132301, 2010: )
The analyticsolution The exactanaliticresult of thesecondorder Gaussian approximation: arethecoefficients of thefirstkindmodifiedBessel-functions
Dependencies of N1(pt) Smalldependenceoninitialtime SensitivitytoEoS
Initialtime EoS Eccentricity Dependencies of v2(pt)