Slide 1

Future Perspectives for Heavy Ions with RHIC & LHC RHIC PHENIX STAR AGS ALICE ATLAS CMS LHC Cover 3 decades of energy in center-of-mass John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012 s NN = 5 - 200 GeV s NN = 5.5 TeV (design)

Slide 2

What Do We Know from RHIC & LHC Consistent Picture of Geometry, Dynamics and Evolution of RHI Collisions John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012

Slide 3

Dynamics & Evolution of RHI Collisions John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012 Muller, Schukraft & Wylsouch, Review, arXiv:1202.3233 Small differences due to initial conditions (PDF shadowing vs geometry, hard processes ~ # binary collisions at LHC vs RHIC)? Glauber vs CGC, Initial state fluctuations, Extent of shadowing LHC pPb data later this year! LHC & RHIC provide consistent picture of dynamics & evolution of collisions multiplicities, system size & lifetimes from RHIC to LHC

Slide 4

What Do We Know from RHIC & LHC Consistent Picture of Geometry, Dynamics and Evolution of RHI Collisions Particle ratios equilibrium abundances universal hadronization T critical Confirm lattice predictions for T critical, B John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012

Slide 5

Particles Formed at Universal Hadronization T Particles yields equilibrium abundances universal hadronization T critical

Slide 6

What Do We Know from RHIC & LHC Consistent Picture of Geometry, Dynamics and Evolution of RHI Collisions Particle ratios equilibrium abundances universal hadronization T critical Confirm lattice predictions for T critical, B It has characteristics of predicted quark-gluon plasma Strongly-coupled liquid Flows with ultra-low shear viscosity John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012

Slide 7

Large Elliptic Flow Observed Implications? John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012 Elliptic Flow v 2 Increase in v 2 from RHIC to LHC x z y Azimuthal asymmetry of particles: dn/d ~ 1 + 2 v 2 (p T ) cos (2 ) +... Predicted by hydrodynamics with very low shear viscosity

Slide 8

Its a Strongly-Coupled Medium with Ultra-Low Shear Viscosity John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012 There exists a universal lower bound on shear viscosity / entropy ratio ( /s): The strong-coupling limit of non-Abelian gauge theories with a gravity dual: /s = 1 / 4 for the perfect liquid Pb+Pb 2.76 TeV 30-40% central ALICE data /s = 0 Viscous hydrodynamics calculations from Schenke, Jeon, Gale, PRL 106 (2011) 042301. 1/4 /s < 1/2 /s = 1/2 /s = 1/4 /s = 0 /s = 1/2 /s = 1/4

Slide 9

Power Spectrum for Heavy Ions Analog WMAP ! John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012 Gaussian width related to length scales such as mean free path, acoustic horizon. Like measurements of early universe sound harmonics Heavy Ion harmonics give key constraints on viscous damping & spatial correlations An acoustic horizon in fluid dynamics (A Mocsy, P. Sorensen, arXiv:1101.1926)

Slide 10

What Do We Know from RHIC & LHC Consistent Picture of Geometry, Dynamics and Evolution of RHI Collisions Particle ratios equilibrium abundances universal hadronization T critical Confirm lattice predictions for T critical, B It has characteristics of predicted quark-gluon plasma Strongly-coupled liquid Flows with ultra-low shear viscosity Its opaque to the most energetic probes Light & heavy quarks are suppressed at large p T Jets quenched and away-side jet energy imbalance John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012

Slide 11

Large Transverse Momentum (p T ) Particles Are Suppressed John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012 CMS, arXiv:1202.2554v1 Suppression R AA = 1

Slide 12

Jets at the LHC Di-Jet Energy Imbalance! Azimuthal Angular Correlations Trigger jet Away-side jet Energy Asymmetry: A J = E T1 E T2 / E T1 + E T2 for /2 E T1 > 100 GeV E T2 > 25 GeV John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012

Slide 13

Where does the Energy Go? CMS dev PRC 84 (2011) 024906 Energy/momentum balance in event is carried by low momentum particles at large angles to jets! John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012 pQCD, vacuum fragmentation, thermalization of lost energy? High energy particles in cone Low energy particles out of cone

Slide 14

What Do We Know from RHIC & LHC Consistent Picture of Geometry, Dynamics and Evolution of RHI Collisions Particle ratios equilibrium abundances universal hadronization T critical Confirm lattice predictions for T critical, B It has characteristics of predicted quark-gluon plasma Strongly-coupled liquid Flows with ultra-low shear viscosity Its opaque to the most energetic probes Light & heavy quarks are suppressed at large p T Away-side jet quenched and jet energy imbalance It has properties of color-screening Suppression of quarkonia (J/ and states) John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012

Slide 15

Quarkonium Melting at LHC and RHIC Quarkonia: cc: , c, J/ bb: , , (Debye color screening, recombination) Color screening of cc pair results in J/ (cc) suppression! Confined Deconfined r V(r) Bound state (e.g. J/ ) Quarkonium dissociation when r Debye ~ 1/( s T) < r qq John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012 T/T C 1/ r [fm -1 ] (1S) J/ (1S) c (1P) (2S) b (2P) (3S)

Slide 16

Quarkonium Melting at LHC and RHIC dev John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012 (1s+2s+3s) Suppression at RHIC Y (b-bbar) cleaner, less recombination than J/ - (heavier) and less thermal - melting sequence vs temperature!

Slide 17

What Do We Know from RHIC & LHC Consistent Picture of Geometry, Dynamics and Evolution of RHI Collisions Particle ratios equilibrium abundances universal hadronization T critical Confirm lattice predictions for T critical, B It has characteristics of predicted quark-gluon plasma Strongly-coupled liquid Flows with ultra-low shear viscosity Its opaque to the most energetic probes Light & heavy quarks are suppressed at large p T Away-side jet quenched and jet energy imbalance It has properties of color-screening Suppression of quarkonia (J/ and states) Still much to be done experimentally and theoretically John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012

Slide 18

Parton Energy Loss in QCD and QGP John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012 Measure radiation products/energy! Measure energy loss of parton! E gluon > E quark, m=0 > E quark, m>0 thus: R AA ( ) < R AA (D) < R AA (B) Important to measure E of gluons light heavy quarks What is the dependence on the type of parton? E How does parton lose energy? q ~

Slide 19

Fundamental Questions about Parton Energy Loss and Implications for the QGP Medium John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012 What are the energy loss mechanisms? radiative = into non-thermal gluon modes collisional = directly into thermal plasma modes How are these affected by the structure of the QGP (quasiparticles or not)? What is QCD at high T? Are AdS/CFT inspired models applicable? What is the weak-strong coupling transition? What happens to the parton energy and momentum lost (medium response?)? If radiative, how quickly does it thermalize i.e., what is its longitudinal momentum (z) distribution? What is its angular distribution (the jet shape) i.e., how much is found in a cone of jet angular size R ? How do the answers depend on flavor of the parton?

Slide 20

Measurements to Determine Parton Energy Loss (Disentangle effects!) Mass and color effects b-quark vs c-quark vs light-quark suppression/propagation! (ALICE, ATLAS & CMS Upgrades) Better secondary vertex discrimination & background suppression Smarter triggering capabilities at lower levels allowing Better statistics on specific signals (vs background!) Establish initial parton kinematics for jets (before parton energy loss!) -jet, Z-jet, di-jets and Z non-interacting in QGP! Gluon vs quark suppression (color factor), use of jets Measure dE/dx (color charge in QCD ala QED!) Virtuality of partons different at RHIC & LHC How to Address Parton Energy Loss John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012 Trigger , Z, jet Away-side jet E gluon > E quark, m=0 > E quark, m>0 Measure pathlength L dependence

Slide 21

Virtuality Q 2 of parton in the medium controls physics of radiative energy loss: Virtuality at RHIC and LHC in pQCD John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012 Trigger , Z, jet Away- side jet Measure pathlength L & E or p T dependence of jets and radiated particles RHIC: 20 GeV parton, L = 3 fm q L 4.5 GeV 2 >> E/L 1.5GeV 2 Virtuality of primary parton is medium dominated and small enough to experience the strongly coupled medium LHC: 200 GeV parton, L = 3 fm q L 9 GeV 2 < E/L 13 GeV 2 Virtuality of primary parton is vacuum dominated and only its gluon cloud experiences the strongly coupled medium B. Mueller, Hard Probes 2012

Slide 22

Detailed investigation of variables (parton attenuation & QGP transport properties) as function of: - Centrality (impact parameter/shape) & Event Plane (Directionality) (Pressure gradients and pathlength dependence) Why Differential Quantities? John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012 x z y Measure & correlate differences in: Parton propagation Transport properties Also dependence on: Momentum Flavor

Slide 23

Suppression of Heavy Flavors John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012 Charm and beauty: No evidence of mass effects yet! B J/ (beauty) arXiv:1201.5069 D (charm) B J/ (beauty) Pions, charm and beauty: Suggestion of a hierarchy! Requires better statistics, esp. for beauty and path-length dependence!

Slide 24

Heavy Quark Energy Loss in the Medium Will b-quarks behave as pQCD predicts (Dead-cone Effectless suppressed)? WHDG prediction for B M. Gyulassy, BNL Seminar 2012 John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012

Slide 25

Detailed investigation of flow as function of: - Particle type (quark content): - Centrality (impact parameter/shape) - Event Plane (Directionality) (Pressure gradients and pathlength dependence) Flow of Heavy Flavors John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012 Requires much better statistics, esp. for path-length dependence! J/ D

Slide 26

Thermal photons shining of the QGP (at RHIC) Must understand the other contributions Spectrum integrates over space-time evolution Real and Virtual Photons at RHIC John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012 PRL 104, 132301 (2010) pp , good agreement with pQCD Exponential fit in p T T = 221 23 18 MeV AuAu In progress at LHC? John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012

Slide 27

Virtual photons Di-leptons Medium modification of resonance & hadron masses Chiral symmetry restoration? Real and Virtual Photons John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012 Virtual photons from decays in QGP Must subtract all hadronic decays outside medium (scale pp data) Centrality dependence: PHENIX, PRC81, 034911(2010), arXiv:0912.0244 Low mass di-lepton Enhancement! Increases with centrality. In progress at LHC?

Slide 28

Low Mass Di-Leptons at RHIC John Harris (Yale) PLHC, Vancouver BC, Canada, 4 - 9 June 2012 PHENIX PRC 81 (2010) 034911 Minbias (value stat sys)Central (value stat sys) STAR 1.53 0.07 0.41 (w/o ) 1.40 0.06 0.38 (w/ ) 1.72 0.10 0.50 (w/o ) 1.54 0.09 0.45 (w/ ) PHENIX 4.7 0.4 1.57.6 0.5 1.3 Difference2.0 4.2 Enhancement factor in 0.15