High Temperature QCD at RHIC With the PHENIX Forward Upgrades Status and fundamental open questions Nature of matter created at RHIC Opportunities for forward upgrades Color screening: Quarkonium spectroscopy (J/ ,  ’,  C,  ) Energy loss mechanism and reaction of medium:   measurements at forward rapidity  -jet and   -jet tomography open heavy flavor Cold nuclear matter effects and initial state Summary

Axel Drees 2 Exploring the Phase Diagram of QCD Quark Matter: Many new phases of matter Asymptotically free quarks & gluons Strongly coupled plasma Superconductors, CFL …. Experimental access to “high” T and moderate  region: heavy ion collisions Pioneered at AGS and SPS Ongoing program at RHIC Quark Matter Hadron Resonance Gas Nuclear Matter sQGP BB T T C ~170 MeV 940 MeV MeV baryon chemical potential temperature Mostly uncharted territory Overwhelming evidence: Strongly coupled quark matter or nearly perfect liquid produced at RHIC Study high T and  QCD in the Laboratory

Axel Drees 3 I. Transverse Energy central 2% PHENIX 130 GeV Bjorken estimate:   ~ 0.3 fm Quark Matter Produced at RHIC  initial ~ GeV/fm 3 Initial conditions:  therm ~ fm/c  ~15-25 GeV/fm 3 II. Flow → Hydrodynamics Heavy ion collisions provide the laboratory to study high T QCD! III. Jet Quenching dN g /dy ~ 1100

Axel Drees 4 system evolutionexpectations collision production of hard probes jets, heavy flavor, quarkonia rapid thermalisation to  ~ 1 fm; T i ~ MeV; energy density ~10-20 GeV/fm 3 opaque, strongly interacting fluid of quarks & gluons thermal photon/dilepton medium effects on jets, heavy flavor, quarkonia J/  suppression collective expansion of charm suppression fireball under pressure jet quenching and shock waves memory effect in yields and spectra elliptic and radial flow crossover to hadrons T C = 170 MeV;  b ~ 0.2 GeV recombination of constituent quarksthermal hadron yields and mass scaling chiral symmetry breaking excess in low mass dileptons collective expansion of memory effect in spectra fireball under pressure thermal freeze-out  ~ 30 fm; T f = 120 MeV end of strong interaction Heavy Ion Collisions at RHIC Energies  cc q g

Axel Drees 5 system evolutionexpectations collision production of hard probes jets, heavy flavor, quarkonia rapid thermalisation to  ~ 1 fm; T i ~ MeV; energy density ~10-20 GeV/fm 3 opaque, strongly interacting fluid of quarks & gluons thermal photon/dilepton medium effects on jets, heavy flavor, quarkonia J/  suppression collective expansion of charm suppression fireball under pressure jet quenching and shock waves memory effect in yields and spectra elliptic and radial flow crossover to hadrons T C = 170 MeV;  b ~ 0.2 GeV recombination of constituent quarksthermal hadron yields and mass scaling chiral symmetry breaking excess in low mass dileptons collective expansion of memory effect in spectra fireball under pressure thermal freeze-out  ~ 30 fm; T f = 120 MeV end of strong interaction Heavy Ion Collisions at RHIC Energies  cc q g  What is the mechanism for rapid thermalization?  What are the properties of QGP? temperature, density, viscosity, speed of sound, screening length … Is it a perfect fluid?  How does deconfined matter transform into hadrons?

Axel Drees 6 Unanswered Fundamental Questions What are the properties of new state of matter? Temperature, density, viscosity, speed of sound, diffusion coefficient, transport coefficients, color screening length Is it a perfect liquid? If it’s a fluid: What is the nature a relativistic quantum fluid? If not: What is it and what are the relevant degrees of freedom? Is chiral symmetry restored? What is the mechanism of rapid thermalization? How does the deconfined matter transform into hadrons? Is there a critical point in the QCD phase diagram? What is the initial state in heavy ion collisions? How does the nucleon get its spin? from “Future Science at the Relativistic Heavy Ion Collider” BNL IR, 12/30/2006 That can be addressed at RHIC

Axel Drees 7 Unanswered Fundamental Questions What are the properties of new state of matter? Temperature, density, viscosity, speed of sound, diffusion coefficient, transport coefficients, color screening length Is it a perfect liquid? If it’s a fluid: What is the nature a relativistic quantum fluid? If not: What is it and what are the relevant degrees of freedom? Is chiral symmetry restored? What is the mechanism of rapid thermalization? How does the deconfined matter transform into hadrons? Is there a critical point in the QCD phase diagram? What is the initial state in heavy ion collisions? How does the nucleon get its spin? from “Future Science at the Relativistic Heavy Ion Collider” BNL IR, 12/30/2006 That can be addressed at RHIC Need precision measurements with hard probes currently not accessible at RHIC  PHENIX forward upgrades are key contributors to answer these questions

Axel Drees 8 Key Experimental Probes of Quark Matter Rutherford experiment   atomdiscovery of nucleus SLAC electron scattering e  protondiscovery of quarks penetrating beam (jets or heavy particles) absorption or scattering pattern QGP Nature provides penetrating beams or “hard probes” and the QGP in A-A collisions Penetrating beams created by parton scattering before QGP is formed High transverse momentum particles  jets Heavy particles  open and hidden charm or bottom Calibrated probes calculable in pQCD Probe QGP created in A-A collisions as transient state after ~ 1 fm

Axel Drees 9 Hard Probes Early deconfinement or color screening: Quarkonia (J/ ,  ’,  C,  ) Produced as bound states in initial hard scattering processes Color screening in QGP Different states expected to melt at different temperature Lattice QCD: J/  may survive up to 1.6 T C Regenerated at harmonization Energy loss: quark and gluon “jets” Produced in initial hard scattering processes Energy loss > 1 GeV/fm in QGP Radiative energy loss Energy loss through elastic collisions Jet quenching leads to collective excitations of medium Energy loss: heavy flavor Produced in initial hard scattering processes Energy loss expected to be smaller than for light quarks q q hadrons leading particle leading particle

Axel Drees 10 Measurement Program Precise reference for hard processes from p+p collisions Control of cold nuclear matter effects with d+Au collisions Initial state of collision: gluon shadowing, color glass condensate Nuclear absorption effects Medium effects observed in A+A as function of density and temperature over large acceptance Centrality of collision Orientation to reaction plane Rapidity Collision energy System size

Axel Drees 11 Hard Probes: Quarkonium Status J/  production is suppressed Large suppression Similar at RHIC and SPS Larger at forward rapidity Ruled out comover and melting scenarios ruled out Consistent with melting J/  followed by regeneration Open issues: Are quarkonia states screened and regenerated? What is the regeneration (hadronisation) mechanism Can we extract a screening length from data? Recent Lattice QCD developments: Quarkonium states do not melt at T C J/  Deconfinement  Color screening

Axel Drees 12 Hard Probes: Quarkonium Status J/  production is suppressed Large suppression Similar at RHIC and SPS Larger at forward rapidity Ruled out comover and melting scenarios ruled out Consistent with melting J/  followed by regeneration Open issues: Are quarkonia states screened and regenerated? What is the regeneration (hadronisation) mechanism Can we extract a screening lenth from data? Recent Lattice QCD developments: Quarkonium states do not melt at T C J/  Deconfinement  Color screening Answers require “quarkconium” spectroscopy with multiple states  ’,  C and  including rapidity, p T and reaction plan dependence Forward upgrades NCC & FVTX: mass resolution (  ’) and photon detection (  C ), charm and bottom measurement Increased luminosity (RHIC II): statistics for  ’, 

Axel Drees 13 Quarkonium Spectroscopy with Forward Upgrades FVTX: Track muons to primary vertex, reject decay background (K   ) Improved mass resolution clean and significant  ‘ Background Rejection  Upsilon at mid rapidity Rapidity dependence J/ ,  ’, and  FVTX: Detected displaced vertex for charm and beauty decays Precise charm and beauty reference NCC: add photon measurement at forward rapidity Measurement of  C →J/  γ possible Au+Au With FVTX

Axel Drees 14 RHIC 2 nb -1 With NCC/FVTX RHIC 2 nb -1 W/O NCC/FVTX RHIC 20 nb -1 With NCC/FVTX Quarkonium Spectroscopy with Forward Upgrades ’’ cc J   S)  S) Reference model based on consecutive melting without regeneration (Note: This results in small  ’,  C yields, other models like regeneration model will give similar yields for J/ ,  ’,  C !)

Axel Drees 15 Hard Probes: Light quark/gluon jets Status Calibrated probe Strong effect in opaque medium Jet quenching Surface bias  limited sensitivity Reaction of medium to probe (Mach cones, recombination, etc. ) Open issues: What is the energy loss mechanism? Which observables are sensitive to details of energy loss mechanism? What phenomena relate to reaction of media to energy loss? peripheral or pp central AuAu hydro vacuum fragmentation reaction of medium

Axel Drees 16 Hard Probes: Light quark/gluon jets Status Calibrated probe Strong effect in opaque medium Jet quenching Surface bias  limited sensitivity Reaction of medium to probe (Mach cones, recombination, etc. ) Open issues: What is the energy loss mechanism? Which observables are sensitive to details of energy loss mechanism? What phenomena relate to reaction of media to energy loss? peripheral or pp central AuAu hydro vacuum fragmentation reaction of medium Answers will come from jet tomography (  -jet): single, two and three particle analysis Forward upgrade NCC (and FVTX): factor ~10 increase of kinematic coverage RHIC II luminosity: p T reach for direct photons

Axel Drees 17 Jet Quenching at Forward Rapidity with NCC  0 production at forward rapidity: Assume factor 5 suppression Luminosity 2 nb -1 and one NCC 10% occupancy in central Au+Au Measure ~ 50  0 at y=2  15% error R AA vers rapidity p T > 5 GeV/c |y| < 2 error <10% p T (GeV/c) R AA NCC at y= y R AA NCC at p T >5 Precision measurement of R AA will distinguish different models! Lack of theoretical predictions!

Axel Drees 18  -Jet Tomography  : jet energy recoil jet: energy loss medium reacting hadron < 4 GeV Emerging analysis technique, proof of principle in pp q qg  p+p collisions at 200 GeV Inclusive  -h Decay  -h contribution Direct  -h

Axel Drees 19 Acceptance for  -jet and  0 -jet Measurement rapidity  0 and prompt photons: central EMCal, MPC Recoil Jet: VTX (charged) (factor ~10 increase)  coverage 2  Large acceptance for   and  jet measurement NCC (factor ~ 10 increase) NCC EMCal MPC VTX FVTX FVTX (limited momentum) NCC (energy)

Axel Drees 20  -Jet Tomography  : jet energy recoil jet: energy loss medium reacting hadron < 4 GeV q qg  limit Run 7 with VTX with NCC with RHIC II NCC and VTX plus RHIC II:  -jet up > 20 GeV  separation of medium reaction and energy loss  sufficient statistics for 3 particle correlations p T > 5 GeV  2-3 particle correlations with identified particles

Axel Drees 21 Hard Probes: Open Heavy Flavor Status Calibrated probe? pQCD under predicts cross section by factor 2-5 Charm follows binary scaling Strong medium effects Significant charm suppression and v2 Upper bound on viscosity ? Bottom potentially suppressed Open issues: Limited agreement with energy loss calculations! What is the energy loss mechanism? Are there medium effects on b-quarks? Electrons from c/b hadron decays

Axel Drees 22 Hard Probes: Open Heavy Flavor Status Calibrated probe? pQCD under predicts cross section by factor 2-5 Charm follows binary scaling Strong medium effects Significant charm suppression and v2 Upper bound on viscosity ? Bottom potentially suppressed Open issues: Limited agreement with energy loss calculations! What is the energy loss mechanism? Are there medium effects on b-quarks? Electrons from c/b hadron decays Answers expected from direct charm/beauty separation Forward upgrade FVTX (and VTX): b-c separation via secondary vertex detection

Axel Drees 23 m c   GeV  m D D ± B B ± Direct Observation of Charm and Beauty Detection options with vertex detectors (FVTX & VTX): Beauty and low p T charm through displaced e and  Beauty via displaced J/    High p T charm through D   K  D Au D X J/  B X  K   B  J /    Prompt J / 

Axel Drees 24 Direct Observation of Charm and Beauty RHIC 2 nb -1 with FVTX

Axel Drees 25 Initial State and Cold Matter Effects p t = p t = p t = p t = y R pA Statistical error bars assuming top 20% p+Au central collisions from run 12 ~0.5 pb -1 Direct Photon in EMC and NCC y distributions Probe initial state in dA Precision measurement with NCC of gluon shadowing and potentially of gluon saturation unmodified GLV LO log x 2 Q=5.6GeV saturated structure function

Axel Drees 26 Cold nuclear matter nuclear matter effects With decay background rejection form FVTX the measurement will by statistics (<5%) rather than by systematic uncertainties! Precise cold matter reference for quarkonium physics Knowledge limited by systematic errors

Axel Drees 27 Summary Table

Axel Drees 28 Perspectives of PHENIX Forward Upgrades New state of the art detectors NCC and FVTX provide vertex tracking and forward calorimetry over large acceptance Enable key measurements and many precision measurements unavailable at RHIC today! Quarkonium spectroscopy: color screening Jet tomography: energy loss and shock waves Forward upgrades will flourish with RHIC II luminosity Designed for RHIC II rates High pT jet tomography Accurate measurements for quarkonia Improved theoretical guidance required phenomenological tools (e.g. 3-D viscous hydro) lattice QCD (e.g. finite density) new approaches (e.g. gauge/gravity AdS/CFT correspondence)

Axel Drees 29 Backup

Axel Drees 30 Long Term Timeline of Heavy Ion Facilities RHIC 2009 LHC FAIR Phase III: Heavy ion physics PHENIX & STAR upgrades electron cooling “RHIC II” electron injector/ring “e RHIC” 2015 Vertex tracking, large acceptance, rate capabilities

Axel Drees 31 RHIC Upgrades Overview UpgradesHigh T QCDSpin Low x e+e-heavyjetquarkoniaW  G/G flavortomography PHENIX hadron blind detector (HBD)X Vertex tracker (VTX and FVTX)XXOO XO  trigger OX forward calorimeter (NCC) OXO X STAR time of flight (TOF) OXO Heavy flavor tracker (HFT) XOO tracking upgrade OO XO Forward calorimeter (FMS) OX DAQ OXXOOO RHIC luminosity OOXXOOO X upgrade critical for success O upgrade significantly enhancements program

Axel Drees 32 Estimates for  -jet Tomography Rapidly falling cross section with rapidity: Assume ~ 1000 events required for statistical  -jet correlation 40x design luminosity ymax  -p T (GeV) Inclusive direct  today Detector + luminosity upgrades Need to extend p T range not obvious! Hadron pid ~ 4 GeV seems sufficient!