Electromagnetic Probesof Strongly Interacting Matter

in Heavy-Ion CollisionB. Kämpfer

Research Center Rossendorf/Dresden

1) Spectra2) Measuring Temperatures3) Advanced Models4) Charm

with K. Gallmeister, S. Zschocke supported by BMBF, GSI

HADES C+C@2AGeV

No Efficiency / Acceptance Correctioninv. Mass [MeV/c2]

dN

/dM

[1.

/MeV

/co

ll.] Simulation

Data

Syst. Error est.

Syst. Bias for M<150 MeV/c2

preliminary

PHENIXPHENIX

STARSTAR

NA60NA60

Experimental Overview

Hadrons in Collisionsmall systems: ll*,

continuous monitoring of evolutionpenetrating probes

emission rates

= ret. current-current correlator= ret. photon self-energy in medium

probes the medium in all stages

Road MapRoad Map

kinetic approaches

spectral functionV-A mixing

Emissivity of MatterEmissivity of Matter

no differenceno differenceof deconfinedof deconfinedand confinedand confinedmatter radiationmatter radiation

Measuring Temperatures

2. Heavy Ion Collisions

1. Universe

use qq rate as test function for thermal yield add hadron cocktail, DY, open charm

WMAPWMAP

<T> = 170 MeV

<T> = 145 MeV

<T> = T_f.o. ?<T> = T_f.o. ?

CERES 2004CERES 2004 Pb + AuPb + Au

CERES 95, 96, 158 AGeVCERES 95, 96, 158 AGeV

<T> = 170 MeV<T> = 170 MeVNA50:NA50: Issue: T vs. NIssue: T vs. N

Photons, tooPhotons, tooGallmeister et al:Gallmeister et al:S beam:S beam:HELIOS-3,HELIOS-3,NA38,NA38,CERESCERES

Low kT:Low kT:Correction a laCorrection a laArnold et al.Arnold et al.

Advanced ModelsAdvanced Models

fireball/hydro: T(t,x), n(t,x)fireball/hydro: T(t,x), n(t,x)

T(0), QGP vs. Hadron Gas T(0), QGP vs. Hadron Gas

SPS 158 AGeVSPS 158 AGeV

Rapp ...Rapp ...Gale...Gale...Ruuskanen ...Ruuskanen ...Srivastava ...Srivastava ...Alam ...Alam ...

transport: no sensitivity to deconfinement transport: no sensitivity to deconfinement

T(0) > Tc T(0) > Tc molten rhomolten rho

Cassing ...Cassing ...Stoecker ...Stoecker ...Srivastava ...Srivastava ...Bass ...Bass ...

further developments: jet radiation, further developments: jet radiation, correlationscorrelations

Predictions for RHICPredictions for RHIC

Turbile, Rapp, Gale 2003Turbile, Rapp, Gale 2003Gallmeister, Kampfer, Pavlenko 1998Gallmeister, Kampfer, Pavlenko 1998

CharmCharm

within NA50 acceptance:within NA50 acceptance: fireball radiation = charm yieldfireball radiation = charm yield

decision by NA60 decision by NA60

Ruuskanen, Vogt, ... Gallmeister:Ruuskanen, Vogt, ... Gallmeister:di-leptons from correlated open charm dominatedi-leptons from correlated open charm dominate

Shuryak: energy loss of charm suppresses this yieldShuryak: energy loss of charm suppresses this yield

??

sqrt(s) = 200 GeV, single esqrt(s) = 200 GeV, single e

Summary• many e+e-, mu+mu-, photon spectramany e+e-, mu+mu-, photon spectra• thermal radiation at CERN-SPS identifiedthermal radiation at CERN-SPS identified T(0) > Tc: T(0) > Tc: deconfinement molten rho: molten rho: chiral symmetry restoration• waiting for more precise spectra at RHICwaiting for more precise spectra at RHIC• charm is at hand: charm is at hand: minor energy loss

Shopping List:Shopping List:• NA60 data (abnormal open charm?)NA60 data (abnormal open charm?)• pp and AA spectrapp and AA spectra• multi-differential spectramulti-differential spectra

R. RappR. Rappdetailed space-time scenariodetailed space-time scenario

adjust T_i, T_f to CERES dataadjust T_i, T_f to CERES data

Issues:Issues:- chemical off-equilibrium- chemical off-equilibrium in deconfined & hadronin deconfined & hadron mediummedium- baryon density effects - baryon density effects

1. VDM: V

V self-energies models

3. sum up all reaction channelsKinetic theory

2.2.

Emission Rate of Deconfined Matter

1. Dileptons1. Dileptons

Improved:Improved:Aurenche,Gelus, Morre, Zaraket (2000)Aurenche,Gelus, Morre, Zaraket (2000)

2. Photons2. Photons

Improved:Improved:Arnold, Moore, Yaffe (2001)Arnold, Moore, Yaffe (2001)

Lattice QCD Lattice QCD Bielefeld 2002Bielefeld 2002