1. 1 R2D: The Case for a comprehensive 2 nd generation RHIC detector R. Bellwied (Wayne State University) for the R2D working group

2. 2 A New Frontier for Heavy Ion Physics ? We discovered strongly coupled partonic, collective matter (sQGP), which is interesting in itself but it will not secure the future of our field. Where do we go from here ? What unique physics can RHIC-II (40 * RHIC-I design luminosity @ 200 GeV) provide during the later stage of the LHC era beyond 2013 ? What are the detailed properties of the sQGP and what are the degrees of freedom at high densities ? What is the mechanism of hadronization and is chiral symmetry restored in the deconfined medium ? Is there another state (CGC) of matter at low x, what are its features, and how does it evolve into the QGP ? What is the structure and dynamics inside the proton (parton spin, L) and what do we learn from parity violation and polarization measurements ? IntroductionUnique PhysicsRequirementsDetector LayoutPerformanceSummary

3. 3 How strong is the sQGP at RHIC and beyond ? Different initial conditions at RHIC and LHC ?? Prediction: v2 should decrease SPS RHIC LHC O.Kaczmarek et al. (hep-lat/0406036) 1.05 T c 1.5 T c 3 T c 6 T c 12 T c coupling decreases as f (T,r) IntroductionUnique PhysicsRequirementsDetector LayoutPerformanceSummary

4. 4 RHIC-II - a unique place to study hadron formation out of a medium Models: Recombination: constituent quark (dressed up valence quarks) A. Peshier (hep-ph/0502138): quasi particles above Tc E.Shuryak (hep-p/0405066): colored & colorless bound states above Tc R.Rapp (hep-ph/0505080): quasi-resonant heavy states above TC Measurements : Particle identified measurements of v 2, jet quenching, resonance shifts and rapidity instabilities Ratios of particles with common valence quarks (e.g.  T.Peitzmann QM poster) Baryon – strangeness number correlations (probes bound states) (V.Koch QM talk) Questions: What are the degrees of freedom above Tc ? Do deconfinement and chirality decouple ? How is baryonic mass (universe) generated from a medium ? IntroductionUnique PhysicsRequirementsDetector LayoutPerformanceSummary Levai/Heinz (massive partons) (hep-ph/9710463)

5. 5 pp at RHIC  adron formation in QCD NLO for heavy masses requires quark separation in fragmentation function ? K0s AKK, hep-ph/0502188 zz In AA: is the fragmentation function modification due to the partonic medium universal ? IntroductionUnique PhysicsRequirementsDetector LayoutPerformanceSummary

6. 6 RHIC-II: a unique place to study energy loss & fragmentation in the strong coupling limit Induced Gluon Radiation  ~collinear gluons in cone  “Softened” fragmentation Modification according to Gyulassy et al. (nucl-th/0302077) Quite generic (universal) but attributable to radiative rather than collisional energy loss  E g =2  E q Eg=EqEg=Eq Non-Abelian energy loss XNW, nucl-th/0410049 but: - potential heavy quark effects - non-Abelian energy loss IntroductionUnique PhysicsRequirementsDetector LayoutPerformanceSummary

7. 7 RHIC-II – a unique place to study low-x physics ? Color Glass Condensate (CGC): gluon saturation at low Q 2. Measure –Mid – forward rapidity correlations (hep-ph/0403271) –Direct photons at forward rapidities –  HBT (coherence of sea- quark source?) –Drell-Yan in forward region (hep-ph/040321) –R pA, R AA of heavy mesons in forward direction (hep- ph/0310358) requires tracking, calorimetry and PID over large  -range. ln (1/x) IntroductionUnique PhysicsRequirementsDetector LayoutPerformanceSummary

8. 8 RHIC-II: a unique place to study the complete onium program –Melting of quarkonium states (Deconfinement T C ) T diss (  ’) < T diss (  (3S)) < T diss (J/  )  T diss (  (2S)) < T diss (  (1S)) In order to resolve the question of melting of the states and its relevance to the sQGP we need to measure: the J/  production mechanism (octet vs. singlet model) (requires pp) the effect of nuclear absorption (requires pA) the effect of thermal recombination the effect of co-mover absorption the feed-down from  c (in pp, pA,AA) all states (in pp, pA, AA) IntroductionUnique PhysicsRequirementsDetector LayoutPerformanceSummary

9. 9 Requirement: track-by-track PID at high pt in large acceptance ! -4-3-2-101234  10 GeV 4 GeV PHENIX STAR, 4 GeV R2D, 25 GeV 0 22  p q,g > 10 GeV/c all  10 6 particles in AA Trigger on flavor tagged jet or photon and measure particle composition IntroductionUnique PhysicsRequirementsDetector LayoutPerformanceSummary

10. 10 Requirement: full coverage and excellent resolution in tracking, and calorimetry  and pT broadening for  +jet  distribution for  c decay Y States resolution in R2D R2D IntroductionUnique PhysicsRequirementsDetector LayoutPerformanceSummary

11. 11 The Ultimate Heavy Ion Detector: Combine high energy experiment precision, hermeticity, field strength and calorimetry with heavy ion experiment capabilities in particle identification and tracking. Prohibitively expensive ?? (requires the utilization of decommissioned HEP detector components (from SLAC, FNAL, DESY)) In particular: use existing magnet, calorimetry, muon chambers &electronics Build new: particle identification and tracking Projected price tag: < $100 Million R2D detector concept: hermeticity and PID R=2.8m IntroductionUnique PhysicsRequirementsDetector LayoutPerformanceSummary

12. 12 Alternative: S-R2D based on CDF (CDF, CLEO & BABAR have same field and magnet radius) SC Coil; R = 1.5 m; B z = 1.5 T EMC, CsI crystal, ~24 X 0 Si Vertex D. R coil = 150 cm AeroGel2 Ch. D. AeroGel1 Ch. D. GEM Tracking D. Si Strip Detectors HC and Muon Detectors Gas RICH Detectors IntroductionUnique PhysicsRequirementsDetector LayoutPerformanceSummary

13. 13 Comparison of RHIC-II/LHC onium programs per run year (thanks to T.Frawley) SignalPHENIXSTARALICECMSR2D J/  →  or ee pp AA 525,000 440,000 1,600,000 8,000 135,900 208,600 17,219 26,400 10,200,000 8,580,000  →  or ee pp AA 9,350 7,900 28,812 140 2,450 3,760 310 480 184,000 154,000  c →  or ee  pp AA 142,000 120,000 (?) ???? ???? ???? 1,560,000 1,320,000 Y(unresolved) pp AA 740 1440 8,300 16,400 1,350 4,860 3,010 10,800 35,200 71,000 Y states (resolved) pp AA 210 400 0000 1,350 4,860 3,010 10,800 35,200 71,000 B → J/  →  or ee pp AA 4,000 8,000 19,000 100 3,580 12,900 573 2,060 68,000 132,000 For more detail & dA : http://rhicii-heavy.bnl.gov/doc/April05Meeting/frawley-lhc-rhich.pdf IntroductionUnique PhysicsRequirementsDetector LayoutPerformanceSummary

14. 14 Comparative Physics Reach: PHENIX-II STAR-II ALICE R2D Deconfinement, chirality and low x physics a.) Onium physics  ’ J/  c  Y(1s) Y(2s) Y(3s) b.) Rapidity gap measurements and forward physics  > 1 > 2 > 3 > 4 > 5 > 6 c.) Chirality measurements low mass di-lepton:: chiral partners::resonances > Tc d.) Degrees of freedom above Tc (w. PID) v2 > 4 GeV/c::R(AA) |  |=1::v2 > 10 GeV/c::R(AA) |  |=3 Fragmentation and hadronization a.) Di-hadron jets 10 GeV 20 GeV 30 GeV 40 GeV b.) Gamma-jet with identified hadrons (h > 5 GeV/c) 5 GeV  10 GeV  15 GeV  20 GeV  c.) Identified high pt di-hadron correlations pp > 3 GeV/c > 5 GeV/c > 10 GeV/c  > 5 GeV/c R2D: a unique device for RHIC-II IntroductionUnique PhysicsRequirementsDetector LayoutPerformanceSummary

15. 15 Why RHIC-II and R2D in the LHC era ? RHIC-II with R2D is a unique place to study: –hadron formation in the strong coupling limit –differences between quark and gluon jet properties –energy loss and fragmentation in the strong coupling limit –saturation as a function of x –a complete onium program Independent of the evolution of the system, the initial conditions will be different. This provides a unique situation, which allows us to study hadron formation and new phases of matter in two different energy regimes. RHIC-II with R2D offers longer running time, higher luminosity, more detailed detector capabilities. LHC offers higher energy and larger cross sections. IntroductionUnique PhysicsRequirementsDetector LayoutPerformanceSummary

16. 16 Expression of Interest - A Comprehensive New Detector for RHIC II P. Steinberg, T. Ullrich (Brookhaven National Laboratory) M. Calderon (Indiana University) J. Rak (University of New Mexico) S. Margetis, C.Markert (Kent State University) M.A. Lisa, D. Magestro, B. Petrak (Ohio State University) R. Lacey (State University of New York, Stony Brook) G. Paic (UNAM Mexico) T. Nayak (VECC Calcutta) R. Bellwied, C. Pruneau, S. Voloshin (Wayne State University) and H. Caines, A. Chikanian, E. Finch, J.W. Harris, M. Heinz, M.A.C. Lamont, J. Sandweiss, N. Smirnov, R. Witt (Yale University) (~80 pages, submitted in August 2004,nucl-ex/0503002) IntroductionUnique PhysicsRequirementsDetector LayoutPerformanceSummary