Jet Tomography of Hot Dense Matter Jet XinNian

Jet Tomography of Hot & Dense Matter Jet Xin-Nian Wang LBNL, June 25, 2003

Equation of States F. Karsch ‘ 2001 Hadrons: QGP: Quarks(2 x 3 x 2 x 2) Gluons(2 x 8)

Medium Response Function Dynamic System: Photon or dilepton emission J/Y suppression QCD Response: (talks by Averbeck, Sinha, Fries, Granier de Cassagnac) Quark scattering

Computed Tomography (CT) Calibrated source Absorption properties Computer assisted correction Image Jet Tomography: Using Parton Jets

Jets: Beams of quarks and gluons Au+Au Jet Tomography Talks by Jacobs, Bathe

EM Radiation EM field carried by a fast moving electron v Final rad. EM Radiation by scattering: Interference between initial and final state radiation Initial rad.

Electron Tomography Classical radiation of a point charge (Jackson, p 671) i j Formation time

Two Limits Factorization Limit: Bethe Heitler Limit: Like a single scattering

LPM Effect Ncoh radiation like from a single scattering Ncoh Landau Pomeranchuck Migdal Ncoh

Radiation in QCD: Colors Make the Difference pi a pf c k k pi pf QED y 0 QCD Gluon multiple scattering (BDMP’ 96) 0 y

DIS off Nuclei e- Frag. Func.

Parton energy loss: A twisted story e- Modified frag. function Parton Energy Loss

HERMES data in Au nuclei

Expanding Medium (GVW, GOW, Wiedemann) Energy loss in a static medium with density

Single spectra in A+A collisions p. QCD Parton Model

Nuclear Modification Factor Initial state effect: Shadowing & pt broadening: XNW, PRC 61(00)064910 Fai, Papp, and Levai (02) Vitev & Gyulassy (02) Vitev (03) LP model Alberto Accardi (01) Color dipole model Kopeliovich et al (02) p. A

Single hadron suppression Talks by: Hwa, Bass, Greco, Molnar

Di-hadron Spectra Hadron-trigger fragmentation function:

Suppression of away-side jet Df

Azimuthal Anisotropy dihadron Single hadron

Azimuthal anisotropy II Talk by R. Lacey, S Voloshin

Partonic Energy Loss at RHIC From RHIC data of Au+Au Collisions Ge. V for E=10 Ge. V Initial Density about 30 times of that in a Cold Au Nucleus Consistent with estimate of initial condition Talks by Venugopalan, Bickley

Energy Loss Is Partonic! Could it be caused by hadronic absorption or rescattering? (1) Hadron formation time: NO! h Uncertainty principle:

Parton Energy Loss: 2 (2) Centrality dependence:

Parton energy loss: (3) PT Dependence:

Parton Energy Loss: (4) • Large v 2 early late Geometrical anisotropy is an early phenomenon!

Parton Energy Loss: (4) (5) Same-side jet profile Same-side jet cone remains the same as in pp collision PHENIX sees the same Hadron rescattering will change the correlation Between leading and sub-leading hadrons

Measuring Parton Energy Loss p. Ttrig ET

Partonic energy loss: (6) SPS

Summary • Discovery of Jet Quenching proves that a strongly interacting dense matter is formed: Opaque to jets • Jet quenching is caused by partonic energy loss • Dense matter at RHIC is 30 times higher than cold nuclei • Collective behavior: Hydrodyamic limit (talks by Csernai, Huovinen, Nonaka) • It has to be QGP within QCD • Jet tomography become useful and power tool for studying properties of dense matter

Hard Probes Collaboration http: //www-hpc. lbl. gov/ Hard Processes in p+p, p+A and A+A • • • Jet and high pt hadron Quarkonium Heavy Quarks Direct Photons DY

Parton Shadowing in Nuclei shadowing EMC

Energy Dependence Thermal absorption important at lower E Detailed balance Enke Wang & XNW PRL 87(01)142301

Medium Modified Fragmentation