the effect of dynamical parton recombination on event-by-event observables

Marcus Bleicher, ISMD Berkeley 08/2007

The Effect of Dynamical Parton Recombination on Event-by-Event Observables

The Effect of Dynamical Parton Recombination on Event-by-Event Observables

Marcus Bleicher & Stephane Haussler

Institut für Theoretische Physik

Goethe Universität Frankfurt

Germany

Marcus Bleicher, ISMD Berkeley 08/2007

ThanksThanks

• Elena Bratkovskaya

• Manuel Reiter

• Sascha Vogel

• Xianglei Zhu

• Horst Stoecker

•Timo Spielmann

• Katharina Schmidt

• Hannah Petersen

• Stephane Haussler

• Daniel Krieg

• Benjamin Lungwitz

Marcus Bleicher, ISMD Berkeley 08/2007

Outline of the talkOutline of the talk

• Introduction

• The Quark-Molecular Dynamics

• Charge fluctuations

• Baryon-strangeness correlations

• Charge transfer fluctuations (see backup)

• Summary

Marcus Bleicher, ISMD Berkeley 08/2007

MotivationMotivation

At RHIC: look for signals of freely moving partons.(D, CBS,)

At FAIR/SPS:look for the mixed phase and the onset of deconfinement(kp

E. Bratkovskaya, M.B. et al., PRC 2005

Marcus Bleicher, ISMD Berkeley 08/2007

Fluctuations are THE tool!?Fluctuations are THE tool!?

• Fluctuations might provide information on- deconfinement/confinement- correlation length- thermalization- nature of the QGP- critical point

• Is it that easy?- finite time and volume- non-equilibrium- hadronization

Marcus Bleicher, ISMD Berkeley 08/2007

Scaled variancesScaled variances

• Non-trivial structuresDetailed non-equilibrium studies necessary

Lungwitz, Bleicher, in preparation

4pi forward

Marcus Bleicher, ISMD Berkeley 08/2007

The tool: qMDThe tool: qMD

qMD : Quark Molecular Dynamics (a toy model for hadronization)

• out-of-equilibrium transport model, (Vlasov equation)

• provides a hadronization prescription

• essentially realizes a dynamical quark recombination approach

Marcus Bleicher, ISMD Berkeley 08/2007

Quark Molecular DynamicsQuark Molecular Dynamics

Marcus Bleicher, ISMD Berkeley 08/2007

TrajectoriesTrajectories

Marcus Bleicher, ISMD Berkeley 08/2007

Hadronization procedureHadronization procedure

Marcus Bleicher, ISMD Berkeley 08/2007

Some properties: equilibriumSome properties: equilibrium

Marcus Bleicher, ISMD Berkeley 08/2007

• For ‘real’ physics use UrQMD initial state

• dissolve strings into ‘free’ quarks

• evolve system with qMD

Marcus Bleicher, ISMD Berkeley 08/2007

Entropy considerationEntropy consideration

<N>

<m>

Marcus Bleicher, ISMD Berkeley 08/2007

Entropy and recombinationEntropy and recombination

Marcus Bleicher, ISMD Berkeley 08/2007

The idea behind conserved charge fluctuations

The idea behind conserved charge fluctuations

Marcus Bleicher, ISMD Berkeley 08/2007

Fluctuations and suceptibilitiesFluctuations and suceptibilities

Marcus Bleicher, ISMD Berkeley 08/2007

Comparison to lQCD (I)Comparison to lQCD (I)

Marcus Bleicher, ISMD Berkeley 08/2007

Comparison to lQCD (II)Comparison to lQCD (II)

Marcus Bleicher, ISMD Berkeley 08/2007

• Hadron gas seems to be pretty similar to QGP…

( A. Majumder et al, Phys. Rev.C 74 (2006) 054901 )

Marcus Bleicher, ISMD Berkeley 08/2007

Charge ratio fluctuationsCharge ratio fluctuations

Marcus Bleicher, ISMD Berkeley 08/2007

Pion gas, D ~ 4

Quark gas, D ~ 1

Marcus Bleicher, ISMD Berkeley 08/2007

Can one observe the fluctuations in the initial state?

Can one observe the fluctuations in the initial state?

See e.g. Shuryak et al, Phys.Rev.C63:064903,2001

Marcus Bleicher, ISMD Berkeley 08/2007

Experimental resultsExperimental results

Marcus Bleicher, ISMD Berkeley 08/2007

Recombination and fluctuationRecombination and fluctuation

part

on f

ract

ion

y=1

Au+Au@200 AGeV

Marcus Bleicher, ISMD Berkeley 08/2007

See also…See also…

• Bialas: Recombination blur ratio fluctuations (Phys.Lett.B532:249-251,2002)

• Nonaka: Recombination blurs ratio fluctuations (Phys.Rev.C71:051901,2005 )

• Ma: Hadronization blurs ratio fluctuations(SQM 2007)

• Present work:

Marcus Bleicher, ISMD Berkeley 08/2007

Baryon-Strangeness CorrelationsBaryon-Strangeness Correlations

Marcus Bleicher, ISMD Berkeley 08/2007

Time evolutionTime evolution

y=1

Au+Au@200 AGeV

Marcus Bleicher, ISMD Berkeley 08/2007

ConclusionsConclusions

Marcus Bleicher, ISMD Berkeley 08/2007

Additional slidesAdditional slides

Marcus Bleicher, ISMD Berkeley 08/2007

Marcus Bleicher, ISMD Berkeley 08/2007

Charge transfer fluctuationsCharge transfer fluctuations

Marcus Bleicher, ISMD Berkeley 08/2007

qMD results on kappaqMD results on kappa

Au+Au@200 AGeV