Scott Pratt Michigan State University Have we seen the QGP at RHIC? Scott Pratt, Michigan State University MORE MEANINGFUL QUESTIONS: 1.Have we created MATTER ? 2.What are the defining properties of the new phase of matter (QGP) we expect to see at RHIC? 3.Is there experimental evidence for having created matter with these properties?

Scott Pratt Michigan State University Have we created MATTER ? 1.Local kinetic equilibrium (even if not chemically equilibrated) 2.Large enough volume for bulk quantities to apply (otherwise we are studying reactions) Requirements for MATTER :

Scott Pratt Michigan State University Have we created Matter ? Kinetic equilibrium: 1. Thermal features to spectra (exponential shape,  -K-p systematics)

Scott Pratt Michigan State University Have we created Matter ? System Size: 1. Elliptic Flow is large Approaching hydro limit -> low visosity -> short mean free path

Scott Pratt Michigan State University Have we created Matter ? System Size: 2. Jets are quenched System is opaque to even high-energy partons!

Scott Pratt Michigan State University Have we created Matter ? YES ! -- and at high energy density, (accounting for longitudinal work and motion, ~ 10 GeV/fm 3 )

Scott Pratt Michigan State University Properties of the QGP 1.Quarks and Gluons are correct quasi-particles 2.Low pressure (compared to  gas at same  ) 3.Low T & high entropy (compared to  gas at same  ) 4.Chiral symmetry restored (shifted  mass) 5.Opaque to jets 6.Large fluctuations (e.g. droplets)

Scott Pratt Michigan State University Are quarks/gluons correct quasi-particles? 1.Balance function Most charge is created at hadronization, especially for gluon-rich medium If +/- pairs are more are created later, they are more correlated in rapidity Late hadronization = narrow B(  y)

Scott Pratt Michigan State University Are quarks/gluons correct quasi-particles? S.P., S.Cheng, S.Petriconi and M.Skoby, in prep. 1. Balance Function Width narrows with increasing centrality QUALITATIVELY consistent with expectations for QGP QUANTITATIVELY consistent with blast- wave with LOCAL charge charge conservation

Scott Pratt Michigan State University Are quarks/gluons correct quasi-particles? S.P., S.Cheng, S.Petriconi and M.Skoby, in prep. Blast Wave Calc. Full canonical treatment Resonances included FSI included STAR acceptance and efficiency included T = 120, v  = 0.7 Totally local NARROWEST POSSIBLE RESULT

Scott Pratt Michigan State University Are quarks/gluons correct quasi-particles? 1.Balance function To do:  Make K + /K - and pbar-p balance functions During hadronization, 1000 partons -> 1000 hadrons 350 gluons ud quarks s quarks -> 2000 ud quarks s quarks  Expand analyses to Q inv, Q out, Q side, Q long  Build the time-of-flight wall !

Scott Pratt Michigan State University Are quarks/gluons correct quasi-particles? 2. Di-lepton measurements   should dissolve  Broad strength for M inv ~ 450 MeV To do: Build time-of-flight wall !

Scott Pratt Michigan State University Are quarks/gluons correct quasi-particles? 3. Jet Quenching & J/Psi  Gluon-rich medium should be opaque to jets  Near T c, matter is strongly interacting To do: Pat yourselves on the back ! Gamma tagging Open charm Search low-pt data for jet remnants S.Pal and S.P., to appear in PLB

Scott Pratt Michigan State University Are quarks/gluons correct quasi-particles? 4.  Flow  Gluon-rich medium should accelerate  s  Hadronic medium should be invisible To do: more statistics

Scott Pratt Michigan State University Is the pressure low? 1. Radial/elliptic flow is large, v ,max ~ 0.7 From fitting , K, p spectra, J. Burward-Hoy, BNL Thermalfest 2001

Scott Pratt Michigan State University Is the pressure low? Compared to STAR: R beam 80% too large R side 10% too large R out 40% too large Similar conclusions: P. Kolb, A.Dumitru, P. Huovinen and S. Bass D. Teaney, PhD thesis, EOS has Phase transition Hydro + RQMD          STAR

Scott Pratt Michigan State University Is the pressure low? NO !

Scott Pratt Michigan State University Is the pressure low? To do: Analyze 3-d correlations for different species Angle between q and outwards axis S.P. and S.Petriconi, to appear in PLB

Scott Pratt Michigan State University Is T low? (or high S ) 1.Lattice calculation give low T vs.  (latent heat) 2. Low T implies high entropy

Scott Pratt Michigan State University Is T low? (or high S ) 1.T 0 is not directly accessible (direct photons) 2.dS 0 /dy 0 due to shocks, viscosity, decoupling 3.Entropy can be extracted from experiment in a model-independent fashion (talk to John Cramer) dS  /dy from HBT & spectra dS K /dy from HBT & spectra or from  /K dS p /dy from d/p For other species, use spectra and guess about R HBT

Scott Pratt Michigan State University Is T low? (or high S ) S.Pal and S.P., in preparation hydro  Bjorken

Scott Pratt Michigan State University Is T low? (or high S ) Conclusions: From hydro perspective, not enough entropy for QGP Adding viscosity might not help Using lower entropy phase, e.g. pion gas, helps Calc.s by T.Humanic, Z.Lin, D.Molnar, S.P. To do: Increase particle ID capabilities out to ~ 1.5 GeV Build the time-of-flight wall ! Measure direct photons

Scott Pratt Michigan State University Is chiral symmetry restored?  meson is perfectly designed,  <<  fireball Difficult to distinguish mass shift/spread from dissolving To do: Build time-of-flight wall ! Talk to Zhangbu Xu

Scott Pratt Michigan State University Is the matter opaque to jets? Suppression of high-pt jets PHENIX STAR Disappearance of away-side jets

Scott Pratt Michigan State University Is the matter opaque to jets? YES! To do:  tagging Search low pt for jet remnants (talk to Fuqiang Wang) S.Pal and S.P. to appear in PLB

Scott Pratt Michigan State University Are fluctuations/ correlations large? Yes, but difficult to identify source jets initial proton overlap HBT-like resonances elliptic flow … To do: 6-D analysis of source of long-range correlations Identify species involved Build time-of-flight wall ! Pray for theoretical help

Scott Pratt Michigan State University Summary 1.Quarks and Gluons are correct quasi-particles 2.Low pressure (compared to  gas at same  ) 3.Low T & high entropy (compared to  gas at same  ) 4.Chiral symmetry restored (shifted  mass) 5.Opaque to jets 6.Large fluctuations (e.g. droplets) ? ? Build the time-of-flight wall ! (Balance function, dileptons, fluctuations, HBT…)