R 2 D Do we need a comprehensive

R 2 D: Do we need a comprehensive 2 nd generation RHIC detector ? Rene Bellwied Wayne State University (for the R 2 D Exploratory Working Group) -The physics case -The requirements -The capabilities -The R 2 D/RHIC-II/e. RHIC synergy 1

Introduction Unique Physics Requirements Detector Layout Performance Summary A New Frontier for Heavy Ion Physics ? We discovered strongly coupled partonic, collective matter (s. QGP), which is interesting in itself but it will not secure the future of our field. We need a new paradigm l What is the unique physics can RHIC-II (40 * RHIC-I design luminosity @ 200 Ge. V) provide during the later stage of the LHC era beyond 2013 ? We can probe QCD in the medium that is relevant during the early universe evolution: l l l What are the detailed properties of the s. QGP and what are the degrees of freedom at high densities ? What is the mechanism of hadronization (baryonic matter formation in the universe) 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 ? 2

Introduction Unique Physics Requirements Detector Layout Performance Summary How strong is the s. QGP at RHIC and beyond ? LHC O. Kaczmarek et al. (hep-lat/0406036) RHIC 1. 05 Tc SPS 1. 5 Tc 3 Tc Different initial conditions at RHIC and LHC ? ? Prediction: v 2 should decrease 12 Tc 6 Tc coupling decreases as f (T, r) 3

Introduction Unique Physics Requirements Detector Layout Performance Summary pp at RHIC: Hadron formation in QCD NLO for heavy masses requires quark separation in fragmentation function ? K 0 s AKK, hep-ph/0502188 z z In AA: is the fragmentation function modification due to the partonic medium universal ? 4

Introduction Unique Physics Requirements Detector Layout Performance Summary RHIC-II - a unique place to study hadron formation out of a medium Questions: l l l What are the degrees of freedom above Tc ? Do deconfinement and chirality decouple ? How is baryonic mass (universe) generated from a medium ? l Models: Recombination: l Levai/Heinz (massive partons) (hep-ph/9710463) l l 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 : l Particle identified measurements of v 2 , jet quenching, resonance shifts and rapidity instabilities l Ratios of particles with common valence quarks (e. g. p/h) (T. Peitzmann QM poster) l Baryon – strangeness number correlations (probes bound states) (V. Koch QM talk) 5

Introduction Unique Physics Requirements Detector Layout Performance Summary RHIC-II: a unique place to study energy loss & fragmentation in the strong coupling limit Modification according to Gyulassy et al. (nucl-th/0302077) § § Induced Gluon Radiation ~collinear gluons in cone “Softened” fragmentation but: - potential heavy quark effects - non-Abelian energy loss Non-Abelian energy loss XNW, nucl-th/0410049 DEg=DEq DEg=2 DEq Quite generic (universal) but attributable to radiative rather than collisional energy loss 6

Introduction Unique Physics Requirements Detector Layout Performance Summary RHIC-II – a unique place to study low-x physics ? Color Glass Condensate (CGC): gluon saturation at low Q 2. Measure ln (1/x) – Mid – forward rapidity correlations (hep-ph/0403271) – Direct photons at forward rapidities – gg HBT (coherence of seaquark source? ) – Drell-Yan in forward region (hep-ph/040321) – Rp. A, RAA of heavy mesons in forward direction (hepph/0310358) requires tracking, calorimetry and PID over large h-range. 7

Introduction Unique Physics Requirements Detector Layout Performance Summary RHIC-II: a unique place to study the complete onium program – Melting of quarkonium states (Deconfinement TC) Tdiss(Y’) < Tdiss( (3 S)) < Tdiss(J/Y) Tdiss( (2 S)) < Tdiss( (1 S)) In order to resolve the question of melting of the states and its relevance to the s. QGP we need to measure: the J/y production mechanism (octet vs. singlet model) (requires pp) the effect of nuclear absorption (requires p. A) the effect of thermal recombination the effect of co-mover absorption the feed-down from cc (in pp, p. A, AA) all states (in pp, p. A, AA) 8

Introduction Unique Physics Requirements Detector Layout Performance Summary Requirement: track-by-track PID at high pt in large acceptance ! 2 p pq, g > 10 Ge. V/c all h Ge. V 10 f PHENIX STAR, 4 Ge. V R 2 D, 25 Ge. V 106 4 Ge. V particles in AA 0 -4 -3 -2 -1 0 1 2 3 4 h Trigger on flavor tagged jet or photon and measure particle composition 9

Introduction Unique Physics Requirements Detector Layout Performance Summary Requirement: full coverage and excellent resolution in tracking, and calorimetry h and p. T broadening for g+jet g distribution for cc decay R 2 D Y States resolution in R 2 D 10

Introduction Unique Physics Requirements Detector Layout Performance Summary R 2 D detector concept: hermeticity and PID The Ultimate Heavy Ion Detector: Combine high energy experiment precision, hermeticity, R=2. 8 m 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 11

Introduction Unique Physics Requirements Detector Layout Performance Summary Alternative: S-R 2 D based on CDF (CDF, CLEO & BABAR have same field and magnet radius) SC Coil; R = 1. 5 m; Bz = 1. 5 T EMC, Cs. I crystal, ~24 X 0 Si Strip Detectors Aero. Gel 2 Ch. D. Aero. Gel 1 Ch. D. HC and Muon Detectors Rcoil = 150 cm Gas RICH Detectors GEM Tracking D. Si Vertex D. 12

Introduction Unique Physics Requirements Detector Layout Performance Summary Comparison of RHIC-II/LHC onium programs per run year (thanks to T. Frawley) Signal PHENIX STAR ALICE CMS R 2 D J/Y → mm or ee Y→ mm or ee 525, 000 440, 000 9, 350 7, 900 142, 000 120, 000 (? ) 740 1440 210 400 4, 000 8, 000 135, 900 208, 600 2, 450 3, 760 ? ? 1, 350 4, 860 3, 580 12, 900 17, 219 26, 400 310 480 ? ? 3, 010 10, 800 573 2, 060 10, 200, 000 8, 580, 000 184, 000 154, 000 1, 560, 000 1, 320, 000 35, 200 71, 000 68, 000 132, 000 pp AA cc → mmg or pp eeg AA Y(unresolved) pp AA Y states pp (resolved) AA B → J/Y → pp mm or ee AA 1, 600, 000 8, 000 28, 812 140 ? ? 8, 300 16, 400 0 0 19, 000 100 For more detail & d. A : http: //rhicii-heavy. bnl. gov/doc/April 05 Meeting/frawley-lhc-rhich. pdf 13

Introduction Unique Physics Requirements Detector Layout Performance PHENIX-II Comparative Physics Reach: STAR-II ALICE Deconfinement, chirality and low x physics a. ) Onium physics Y’ J/Y cc Y(1 s) Y(2 s) Y(3 s) Summary R 2 D Fragmentation and hadronization a. ) Di-hadron jets 10 Ge. V 20 Ge. V 30 Ge. V 40 Ge. V b. ) Rapidity gap measurements and forward physics Dh > 1 >2 >3 >4 >5 >6 b. ) Gamma-jet with identified hadrons (h > 5 Ge. V/c) 5 Ge. V g 10 Ge. Vg 15 Ge. Vg 20 Ge. Vg c. ) Chirality measurements low mass di-lepton: : chiral partners: : resonances > Tc c. ) Identified high pt di-hadron correlations pp > 3 Ge. V/c > 5 Ge. V/c > 10 Ge. V/c LL> 5 Ge. V/c d. ) Degrees of freedom above Tc (w. PID) v 2 > 4 Ge. V/c: : R(AA) |h|=1: : v 2 > 10 Ge. V/c: : R(AA) |h|=3 R 2 D: a unique device for RHIC-II 14

Introduction Unique Physics Requirements Detector Layout Performance Summary Why RHIC-II and R 2 D in the LHC era ? l RHIC-II with R 2 D is a unique place to study: – – – l l 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 R 2 D offers longer running time, higher luminosity, more detailed detector capabilities. LHC offers higher energy and larger cross sections. 15

Introduction Unique Physics Requirements Detector Layout Performance Summary A joint e. RHIC/RHIC-II program – BNL: The QCD lab of the future A collaborative effort between RHIC-II and e. RHIC could lead to a joint program starting in less than a decade. The heavy ion community could put certain detector components on a fast track, and collaborate on joint detector components which could be used in AA and e. A running. At least for some time one could envision sharing of beam time and detectors for a joint e. A/AA program. Nearest Goal: joint program should be highest priority in the next NSAC LRP (due in 2007 ? ) See talk by Bernd Surrow (tomorrow) on e. RHIC detector R&D 16

Introduction Unique Physics Requirements Detector Layout Performance Summary The R 2 D concept in e. RHIC 17

Introduction Unique Physics Requirements Detector Layout Performance Summary Possible “CDF/CLEO set-up” for R 2 D / e. RHIC (very preliminary) Hadron Calorimeter / Muon Detector R 300. EMC; Fe+Sc 0. SC Coil; R = 1. 5 m; Bz = 1. 5 T 200. Z EMC, Cs. I crystal, ~8 X 0 Aero. Gel 2 Ch. D. 150. RICH Aero. Gel 1 Ch. D. GEM Tracking D. A, p, e- A, p Barrel Tracking and Pi. D Variant A: Two TPC+Ch. D. systems. Pad Detectors with Cs. I (UV converter) in the same gas volume to use TPC “working” gas as UV radiator. First; C 4 H 10 (C 2 H 6) ? Second: CF 4 Maximum drift time ~10 μs TPC readout: GEMs+pads + Micro. Pattern Gas Detectors Variant B: 5 -6 layers of Si strip Detectors + Micro. Pattern Gas Detectors + RICH gas Detector RICH / TRD. EMC; Fe+Sc Si Vertex D. EMC, Cs. I crystal, ~16 X 0 End Cap Tracking and Pi. D Si + Micro. Pattern Gas Detectors + RICH gas Detector ( or TRD in “e-side” , e. RHIC) 18

Introduction Unique Physics Requirements Detector Layout Performance Summary The Heavy Ion Community needs to make decisions about the future, some of us have already… Many of our colleagues commit to LHC heavy ion projects in ALICE, CMS, and ATLAS. Committing to the LHC and RHIC-II is not mutually exclusive as long as commitments are made early. A joint new detector with e. RHIC might be beneficial to both communities as long as issues of detector compatibility, detector construction, and beam time sharing can be worked out early. The goal should be to make the BNL-QCD lab (RHIC-II and e. RHIC communities) the highest NSAC priority in the next LRP. 19

Introduction Unique Physics Requirements Detector Layout Performance Summary 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) 20