Argonne National Laboratory, 27 Feb Comprehensive RHIC II Detector Ideas for a Comprehensive New Detector for In-Depth Study of the QGP, Initial Conditions and Spin Physics at RHIC II* R. Bellwied (Wayne State), J.W. Harris (Yale), N. Smirnov (Yale), P. Steinberg (BNL), B. Surrow (MIT) and T. Ullrich (BNL) Statement of Interest document at * RHIC II  40 x RHIC design luminosity!

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector PHOBOS BRAHMS Relativistic Heavy Ion Collider Facility RHIC AuAu Design Parameters: Beam Energy = 100 GeV/u No. Bunches = 57 No. Ions /Bunch = 1  10 9 T store = 10 hours L ave = 2  cm -2 sec -1 RHIC AGS LINAC BOOSTER TANDEMS Pol. Proton Source High Int. Proton Source 9 GeV/u Q = MeV/u Q = +32 HEP/NP  g-2 U-line BAF (NASA) STAR PHENIX RHIC II Parameters: Beam Energy = 100 GeV/u No. Bunches = 112 L ave = 8  cm -2 sec -1 RHIC II pp Parameters: Beam Energy = 250 GeV/u L ave = 5  cm -2 sec -1 RHIC pp Design Parameters: Beam Energy = 250 GeV/u L ave = 1.5  cm -2 sec -1

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Outline Present Understanding of Results from RHIC Physics at RHIC in an LHC Era How to Harvest this Physics A New Detector for RHIC II Physics Emphasis Detector Requirements Possible Detector Design Physics Performance Focus: (hard probes) determine properties of QGP low-x physics Color Glass Condensate polarization physics improve statistics rare processes preview

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Preview - Physics at RHIC II in an LHC-era Compelling Physics with RHIC II –Establishing the initial conditions at low x (forward rapidities) saturation / color glass condensate –Parton tomography of the QGP (all rapidities) –Melting of the “Onium” States [J/ ,  ’, Y(1s), Y(2s), Y(3s)] –Determination of the structure and dynamics of the proton rare processes: sea polarization, parity-violating processes How to Harvest this Physics?  Utilize Hard Probes –Jets –High-p T PID particles –  -high-p T correlations –Muon pairs for J/ , Y(1s), Y(2s), Y(3s) General Detector Requirements – ~4  EM + hadronic calorimetry – high resolution tracking (in large  B  dl ) – PID to p ~ GeV/c (flavor tagging) – high rate DAQ and specialized triggering

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Characteristics of Collisions at RHIC from Experiments Global observations: Large produced particle multiplicities  dn ch /d  |  =0 = 670, N total ~ 7500  92% of (>15,000) quarks of final state are produced quarks Large energy densities  dn/d  dE T /d   GeV/fm 3  –  Large elliptic flow  large early pressure gradients and gluon densities  scales as number of quarks in particles, partonic flow?  saturates hydrodynamic limit, quark-gluon equation of state! “Chemical” equilibration (particle yields & ratios): Small net baryon density  K + /K -,  B/B ratios)  B ~ MeV Particle ratios  quark coalescence / recombination Chemical freezeout T  from global particle ratios)  T = 177 MeV,  B = 29 MeV  T ~ T critical (QCD) “Thermal” equilibration (particle spectra) : Thermal freezeout + large transverse flow  T FO = MeV,  T  = 0.5 – 0.6c Hard scattering probes: Suppression of high Pt particles and Quenching of away-side jets (central Au + Au)  opaque to fast light partons  final state effect in Au + Au  dN g /dy ~ 1100  > 100  o 1 2

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Inclusive Hadron p t -spectra:  s = 200 GeV AuAu power law:  pp = d 2 N/dp t 2 = A (p 0 +p t ) -n Preliminary STAR

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Comparison of Hadron Spectra in AA to NN Nuclear Modification Factor R AA : AA = Nucleus-Nucleus NN = Nucleon-Nucleon Nuclear overlap integral: # binary NN collisions / inelastic NN cross section NN cross section AA cross section AA (pQCD) Parton energy loss  R < 1 at large P t

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Suppression of High P T Particles at RHIC The hard scattering data at RHIC in pp, AuAu and dAu collisions establish existence of a new final-state effect – early parton energy loss – in dense matter (a new state of matter? ) in central AuAu collisions Au + Au Experimentd + Au Control Experiment Preliminary DataFinal Data

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Jet Quenching in Au + Au Relative to p + p Assume: high p T triggered AuAu event is a superposition: high p T triggered p+p event + elliptic flow of AuAu event v 2 from reaction plane analysis A* from fit in non-jet region (0.75 < |  | < 2.24) Peripheral Au + Au Away-side jet Central Au + Au disappears 4 < p T (trigger) < 6 GeV/c 2 < p T (assoc.) < p T (trigger)

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector High P T Suppression  Jet Quenching at RHIC High Pt hadrons suppressed in central Au + Au enhanced in d + Au Back-to-back Jets Di-jets in p + p, d + Au (all centralities) Away-side jets quenched in central Au + Au  emission from surface x

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Nuclear modifications in dAu at  = 3.2! New dAu Forward Measurements at RHIC Saturation at low x (10 -3 )? BRAHMS, R. Debbe (QM-2004) PRL (2003)

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector The Color Glass Condensate for review see E. Stancu & R. Venugopalan hep-ph/

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Predictions from Theory for pAu and dAu Hard Scattering I. Vitev nucl-th/ v2 Color Glass Condensate D. Kharzeev et al., PR D68:094013,2003 Y=0 Y=3 Y= -3 CGC at y=0 Very high energy As y grows

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Nuclear modifications in dAu at  = 3.2! RHI Physics at RHIC (II) in an LHC-era Saturation at low x (10 -3 )? LHC ions saturated (y cm )? RHIC in unique region! y cm  final state effects forward  initial state HERA  RHIC  LHC  eRHIC BRAHMS, R. Debbe (QM-2004) PRL (2003)

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Physics at RHIC II in an LHC-era – already previewed! Compelling Physics with RHIC II –Establishing the initial conditions at low x (forward rapidities) saturation / color glass condensate –Parton tomography of the QGP (all rapidities) –Melting of the “Onium” States [J/ , Y(1s), Y(2s), Y(3s)] –Determination of the structure and dynamics of the proton rare processes: sea polarization, parity-violating processes How to Harvest this Physics?  Utilize Hard Probes –Jets –High-p T PID particles –  -high-p T correlations –Muon pairs for J/ , Y(1s), Y(2s), Y(3s) General Detector Requirements – ~4  EM + hadronic calorimetry – high resolution tracking (large  B  dl ) – PID to p ~ GeV/c (flavor tagging) – high rate DAQ and specialized triggering

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Measure QGP Properties & Shadowing/Saturation/CGC (low-x forward physics) with Hard Probes – some examples: –Measure modification of FF’s as parton traverses QGP via jets, photons, high-p T identified particles –Measure initial conditions (saturation) vs final state (parton E-loss) effects x-dependence – compare pA, AA, forward- vs mid-rapidities –Determine initial energy of the parton scattering for accurate E-loss via Photon-tag on opposite side (rates are low) –Measure flavor-dependence of jet quenching via  -jet,  -leading hadron, di-hadrons, di-jets (even lower rates) displaced vertices for D- and B-decays (reduced E-loss for heavy quarks) –Measure deconfinement via melting of the Y(1s), Y(2s) and Y(3s) states e and  identification Measure Polarization in Proton and Rare Processes with Hard Probes: –Heavy flavor production (polarized and unpolarized gluon distn’s) –Jet physics (for polarization in proton) –Electro-weak Physics (W+, W- decays for polarization of QCD sea) –Physics beyond the Standard Model (parity-violating interactions) Some Details on Interesting Physics at RHIC II

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Detailed Study of the QGP and Initial Conditions F QGP (  g QGP ) = f initial (√s, A 1 +A 2, b, x 1, x 2, Q 2 )  f QGP (p T ,y ,  ,p T jet,y jet,  jet,flavor jet,  flow ) Probes –Jets –High p T identified (light-, s-, c-, b-quark) particles –photons –  -jet,  - high-p T identified particle, particle-particle, di-jets Use Hard Probes over Multi-Parameter Space: –Energy - √s –Geometry - system A 1 +A 2, impact parameter b –Rapidity (x-dependence) to forward angles –Transverse momentum of jet / leading particle –Particle type (flavor) –Orientation relative to flow plane (  flow ) –Photon-tag on opposite side

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Detailed “Tomography” of the QGP  /parton parton flow plane F QGP (  g QGP ) = f initial (√s, A 1 +A 2, b, x 1, x 2, Q 2 )  f QGP (p T ,y ,  ,p T jet,y jet,  jet,flavor jet,  flow )

Detailed QGP “Tomography”  parton parton  parton parton  parton parton  parton parton , parton parton  parton parton  jet  leading particle (light-, s-, c-, b-quark) jet leading particle (light-, s-, c-, b-quark) leading particle (light-, s-, c-, b-quark)  parton parton

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Flavor-tagged Phenomena Strange and charmed hadron/antihadron asymmetry –Leading particle effect (e.g. E791, hep-ex/ ) Intra-jet strange hadron production –Difference in gluon and quark jets (e.g. OPAL, hep-ex/ ) Fragmentation function parametrizations for heavy hadrons –Flavor quenching, dead cone effects (e.g. hep-ph/ ) Additional production mechanisms for s,c,b hadrons –Recombination or gluon radiation (e.g. nucl-th/ ) Transverse and longitudinal  polarization –Disappearance in AA (e.g. nucl-th/ ) General Jet Phenomena Rapidity gaps between jets –Difference between quark and gluon jets (e.g. hep-ph/ ) Jet like contributions outside the jet cone (pp, pA, AA) –‘pedestal effect’, small vs. large angle gluon radiation (e.g. Stewart, PRD42 (1990) 1385, hep-ph/ ) Measure Modifications in pp vs pA vs AA

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Relativistic Heavy Ions –Jets, high p T leading particles: Excellent  p/p up to p T = 40 GeV/c (y cm ) Electromagnetic / hadronic calorimetry over ~4  phase space Particle identification out to high p T (p ~ GeV/c) hadron ( ,K,p) and lepton (e/h,  /h) separation central and forward –Flavor dependence: Precision vertex tracking (displaced vertices c/b-decays) –Onium: Large solid angle coverage for e and  High rate (40kHz) detectors, readout, DAQ, trigger capabilities. More on Detector Requirements

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Spin (polarized pp) –Heavy Quark Production (gluon polarization): e ,   detection open beauty production as probe of gluon polarization leading order diagram for heavy quark production in gg-fusion: –QCD (especially jet physics, gluon polarization): jet reconstruction (EM + hadron calorimetry) single-photon detection (  /π o separation), b/c-tagging leading order diagrams for gluon-initiated jets: –Electroweak Physics (QCD sea polarization via W  ): W   e ,   + X requires forward e and  detection, no away-side jet e,  triggers large forward acceptance –Physics beyond the Standard Model (parity violating processes): e and  detection, jet reconstruction, b/c-tagging, missing energy More on Detector Requirements II

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Full acceptance in barrel and forward/backward region (0 < |  | < 3-4) –Tracking –High-rate capabilites (pixel, silicon and GEM-type detectors) –Precision inner vertex detector system - secondary vertex reconstruction, momentum resolution –Particle Identification – , K, p to ~20-30 GeV/c –precision inner vertex detector system - secondary vertex reconstruction, momentum resolution –Electromagnetic and hadronic energy –transverse and longitudinal tower segmentation (for jet reconstruction and electron/hadron separation). Specialized calorimeter / tracking beyond |  |~4 at small x for E missing  system in barrel and forward/backward region for heavy flavors Large  B  dl, B ~ 1.5 T over 2 m. Precise relative luminosity measurement at high-rates Local polarimeter & absolute luminosity measurement High rate DAQ, triggering for rare processes, secondary-vertex trigger Detector Specification

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Re-cycle existing equipment –Utilize detector components from other collider experiments that are decommissioned, or will be in the near future, e.g. SLD, CDF, D0, CLEO –Should be possible to identify and procure existing high field magnet and a large amount of electromagnetic and/or hadronic calorimetry. Build new fast detectors, electronics, DAQ, triggers –New technologies, tracking, PID, electronics, DAQ, triggering Approach CDFD0CLEOALEPHSLD Magnet1.4T,SC2.0T,SC1.5T,SC 1.5T-upg-SC R in m L in m Bdl HCalFe/Sc, 0.78/√E LiquidAr, 0.62/√E NoFET str tube 0.65/√E FET str tube 0.85/√E EMCPb/Sc, 0.13/√E LiquidAr, 0.15/√E CsI crys, 0.03/√E Pb/W, 0.18/√E LiquidAr, 0.15/√E  detector yes Decommis- sioned ? yes

Y X R = 2.8 m SLD magnet, hadronic cal. +  -chambers |  | < 3 (depth = 15 x (5 + 5) cm, r  = 0.3 cm,  z = 3 cm) π/K/p (1-30 GeV/c) PID: Gas RICH (C5F12) with Spherical Mirror Read-out: CsI pads sensitive to UV and MIP AeroGel Cherenkov Detectors with two values of N SC Magnet Coil, 1.5 T EMC: Crystals + Fe(Pb)/Sc (accordion type, projective) or LAr 6x6 mrad towers Additional Tracking: Si Vertex, 4 Pad Detectors in Barrel and End Caps (  -pattern) Si + Pad Detectors Forward dZ = 3.0 m 3-6 layers Si-strip detectors or mini-TPC ToF RPC’s R = 2.8 m A Proof of Principle

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Detector parameters to consider: –Particle identification (PID) reach in momentum –Pseudo-rapidity coverage –Detector resolutions: momentum, energy, two-track –Data acquisition (DAQ) rate A new comprehensive detector would be superior to: –Upgraded STAR in terms of resolution, PID, coverage (inc. calorimetry), rate –Upgraded PHENIX in terms of PID, coverage (inc. calorimetry) –ALICE in terms of PID, coverage, resolution, statistics/operation (pp, pA?, AA) –CMS in terms of PID, statistics/operation (pp, pA?, AA) Detector Parameter Considerations

Comprehensive RHIC II Detector Detector Coverage p (GeV/c) A1+ToF A1+A2+RICH RICH ToF PID ( , K, p)

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Tracking Detectors under Consideration Tracking Detectors in Barrel Simulation Detector R position half-length Sigma-r  Sigma-Z Thickness (cm) (cm) (cm) (cm) (cm) Vertex detector[1][1] 1. APS or Si Pixel Main tracker 2a. Si strip sided or 2b. miniTPC 22.5 – Mylar + Gas (35 pad rows with 0.2x0.8 pad size) High p T tracker 3. Micro-pattern pad detector G Gas Mylar [1][1] Only two vertex detector layers were used in the track reconstruction of this simulation. These were Si pixels of 20  100  m 2 size at 6.5 and 10.5 cm radii.

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Y X R = 2.8 m SLD magnet, hadronic cal. +  -chambers |  | < 3 (depth = 15 x (5 + 5) cm, r  = 0.3 cm,  z = 3 cm) π/K/p (1-30 GeV/c) PID: Gas RICH (C5F12) with Spherical Mirror Read-out: CsI pads sensitive to UV and MIP AeroGel Cherenkov Detectors with two values of N SC Magnet Coil, 1.5 T EMC: Crystals + Fe(Pb)/Sc (accordion type, projective) or LAr 6x6 mrad towers Additional Tracking: Si Vertex, 4 Pad Detectors in Barrel and End Caps (  -pattern) Si + Pad Detectors Forward dZ = 3.0 m 3-6 layers Si-strip detectors or mini-TPC ToF RPC’s R = 2.8 m Tracking

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Momentum Resolution dPt/Pt, % Pt, GeV/c dPt/Pt, % Pt, GeV/c IηI < <IηI < 1.6 IηI > 2.2 IηIIηI Pt = 10. GeV/c Pt = 2. GeV/c Pad detectors only all tracking detectors

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Fast tracking detectors complement fast PID, calorimetry –40x improvement in DAQ rate compared to STAR High resolution EM calorimeter and  chambers –allows resolution of all Y states Near 4  coverage in tracking, PID, calorimetry –20x improvement in heavy quark probes compared to PHENIX (> 20,000 Y per RHIC year, and still > 3000 Y(3s)) PID out to GeV/c over ~4  with high two-track resolution tracking –Measure actual jet physics rather than leading particle physics Particle identify all particles in jet Measure intra-jet correlations between identified hadrons in jet –Direct heavy flavor tagging of jets via leading particle reconstruction  -jet measurements with away-side spectrum out to 20 GeV/c (20 weeks at 40L o ) –p T = 10 GeV/c2.6 M events - p T = 15 GeV/c260 K events –p T = 20 GeV/c30 K events Various Aspects of Detector  Extend the Physics Reach

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Nuclear Matter at High Temperature and Density QCD Potential QCD Potential in vacuum: - strong attractive force - linear increase with distance from color charge - confinement of quarks to hadrons baryons (qqq) and mesons (qq) QCD Potential in dense matter: - screening of color charges (similar to Debye screening in dense atomic matter) - potential vanishes for large distance - deconfinement of quarks  QGP

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Sequential “Melting” of the Onium States Melting Sequence as T increases Charmonium sequence –  (2s) –  c (1p) –  (1s) Bottonium sequence –Y(3s) –Y(2s) –Y(1s) Lattice Calculations Needed! Melting T uncertain

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Lattice QCD Calculations / Schematic Onium Melting q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q q F. Karsch, hep-ph/ T C ~ 175 MeV   C ~ 1 GeV/fm 3  ~ 2 GeV/fm 3  15 GeV/fm 3  50 GeV/fm 3 ,  ’,  c, Y(3s) melts J/  Y(2s) melts Y(1s) melts

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Charmonium Mass Reconstruction and Rate   e+e- (1S) (2S) full scale simulation / reconstruction (3S) RHIC II –assume  Ldt = 10 nb -1 –4 weeks run –from PYTHIA in |  | < 2.5 Y  e + e - –Y(1s) = 19,100 –Y(2s) = 3,200 –Y(3s) = 3,200 Y   +  - –same as above

Argonne National Laboratory, 27 Feb. 2004Comprehensive RHIC II Detector Unique physics at RHIC II with LHC running –Detailed QGP tomography, onium, saturation / CGC, spin physics Comprehensive detector system can harvest this physics –Proof of principle –Maximize physics output from RHIC II Detailed simulations to optimize detector configuration Interest in community –Next generation of RHI physics in U.S. –More theoretical input / guidance –Experimental interest? –Comments Summary “Statement of Interest” document and Presentation at RHIC Planning Meeting on web at R. Bellwied, J.W. Harris, N. Smirnov, P. Steinberg, B. Surrow, T. Ullrich