April 12, 2011Dr. Edward O’BrienDIS PHENIX 2020 DIS2011 Newport News, VA April 12, 2011

April 12, 2011Dr. Edward O’BrienDIS Overview

April 12, 2011Dr. Edward O’BrienDIS The RHIC Physics Program RHIC’s program focuses on the exploration of the QCD phase diagram We started out searching for evidence of QGP in HI & components of proton spin in p+p Hot partonic matter above the QCD transition temperature Identification and characterization of the sQGP Spin components of the proton (S q, S g, S sea q, L orbit ) Gluon saturation at low x and high density, nuclear structure and search for evidence of Color Glass Condensate QCD critical point

April 12, 2011Dr. Edward O’BrienDIS RHIC’s Accomplishments RHIC has been operating since 2000 (We are currently taking data in Run-11) RHIC accelerator has collided 4 different species at 10 different energies Au+Au, Cu+Cu, d+Au, p+p ( s ½ = 7.7, 9.2,11.5, 22, 39, 56, 62, 130, 200, 500 GeV) All initial design parameter have been exceeded with the exception of polarization (but we’re close) ~ 7 Pbytes of raw physics data recorded to date Data production takes places at multiple sites US, Japan, France, Korea > Level 1 triggers have been taken by the experiments 200+ PhD’s, > 250 scientific publications, 100+ PRLs and a few interesting discoveries

April 12, 2011Dr. Edward O’BrienDIS HI Collisions at RHIC Generate Strongly Coupled Partonic Matter (an sQGP) Define: Nuclear Modification Factor R AA Particles made of quarks show energy loss – Jet quenching Direct photons do not All hadrons show energy loss out to a surprisingly high pT

April 12, 2011Dr. Edward O’BrienDIS More sQGP Effects Resultant particles from HI collisions show a large anisotropy (v2) The anisotropic flow scales with quark number – Partonic in nature The flow is consistant with near-perfect for a fluid with hydrodynamic behavior This combined with high opacity derived from jet- quenching lets us derive  /s to be close to the quantum mechanical limit :  /s ~ 1/4  RHIC o K

April 12, 2011Dr. Edward O’BrienDIS and More sQGP Characteristics An excess of direct photons is observed where one would expect to see a thermal photon signal in most HI collisions The pT distribution can be translated into a temperature : T=221 MeV ± 19 MeV stat ± 19 MeV sys Equivalent to an initial temp of MeV or x o K

April 12, 2011Dr. Edward O’BrienDIS and yet More sQGP effects J/  production is suppressed, but not as much as one would have expected in a sQGP due to color screening length. J/  is suppressed at more forward rapidities than at y=0, also unexplained Preliminary indications are that  production is also suppressed. This is also hard to explain.

April 12, 2011Dr. Edward O’BrienDIS One Final Effect Seen in the sQGP Heavy quarks also lose energy and flow inside the hot partonic matter. A surprising result, and especially surprising if this is true for both c and b quarks.

April 12, 2011Dr. Edward O’BrienDIS Next Direction for sQGP Investigations We need to better understand the physics behind energy loss. – Upgrade detector to look at open charm and bottom production systematically  Add silicon vertex detector – Add high performance jet measuring capability  Hadronic calorimetry  Triggerability  High DAQ rate  Large area coverage

April 12, 2011Dr. Edward O’BrienDIS Meanwhile in the Polarized Proton Program Gluon spin contribution to the aggregate proton spin is < 0.2 and tends toward 0. Need to investigate spin of sea quarks S sea, orbital angular momentum of the partons in the proton L orbit or extreme x-range for  G A L measurements of flavor- selected quarks via production of W ± in polarized proton collisions has just begun

April 12, 2011Dr. Edward O’BrienDIS What is Next for Proton Spin? Further progress in measuring a small  G requires upgraded accelerator luminosities and improved polarizations Investigation of flavor-selected quark spin requires RHIC delivers a few 100 pb-1 of integrated luminosity 500 GeV – Accelerator upgrades are underway PHENIX detects the W through single lepton decays – Upgrade detector to improve single muon trigger capability by a factor of – Add LVL1 trigger electronics to the Muon CSCs and Muon RPCs to the Muon Spectrometer arms.

April 12, 2011Dr. Edward O’BrienDIS Current and Near Term

April 12, 2011Dr. Edward O’BrienDIS PHENIX Today

April 12, 2011Dr. Edward O’BrienDIS PHENIX In we are adding major equipment to PHENIX –Silicon Vertex Barrel (VTX) –Silicon Vertex Endcap (FVTX) –Muon Trigger (RPCs + MuTracker LVL1 electronics) –DAQ and Trigger Upgrades ( New muon trigger, vertex trigger, event builder and data collection modules) We are beginning a multi-year program of heavy quark studies in HI collisions and W asymmetry measurements in polarized p+p collisions HI charm, bottom studies p+p quark spin

April 12, 2011Dr. Edward O’BrienDIS Recent PHENIX Upgrades This year PHENIX has added: 4.5M channel Si Vertex barrel Muon Trigger system to improve single muon rejection by 100x Upgraded DAQ Later in 2011 we will be adding: Two Si Vertex endcap detectors (~1M channels total)

April 12, 2011Dr. Edward O’BrienDIS Future Direction

April 12, 2011Dr. Edward O’BrienDIS sQGP Questions Remaining to be addressed Are quarks coupled to the sQGP at all distance scales? What are the mechanisms behind parton-sQGP interactions? What is the energy loss formula? How is equilibrium achieved so rapidly? Are there quasi-particles in the sQGP and do they have a role in equilibration? Is there a relevant screening length in the sQGP? All of these questions would benefit from a high quality hadronic calorimeter that has: Good energy resolution : 50%/ √E High rate capability Triggerable Large acceptance

April 12, 2011Dr. Edward O’BrienDIS Advantage of Hadronic Calorimetry The most accurate way to measure jet energy (within reason) Jets have a huge rate advantage If done well can optimize for low energy trigger threshold – 5-10 GeV – Significantly less systematic uncertainty than current jet measurement techniques of leading particle and correlations Once calorimetry in upgraded other physics capabilities come along for the ride – High statistics J/ ,  ’ – Separation of  states – Dijet  -jet and HQ-jet correlations – High statistics for Direct ,  * Physics

April 12, 2011Dr. Edward O’BrienDIS PHENIX Decadal Upgrade

April 12, 2011Dr. Edward O’BrienDIS The Upgrade Detector What remains: VTX and FVTX EMCal in Forward Arm DAQ Infrastructure (LV, HV, Safety…) What is new: Hadronic Calorimetry Preshower detector Additional tracking layer of Si at ~ 40cm 2T solenoid (R = cm) Barrel EMCal (maybe new) Forward Arm with RICH and GEM tracker Can be built incrementally

April 12, 2011Dr. Edward O’BrienDIS Performance A rather detailed GEANT4 simulation has been implemented for the proposed Decadal upgrade. All performance parameters needed for initial physics objectives appear to be met. Good momentum resolution w/ compact tracker With 2 cm Moliere radius EMCal acceptable occupancy for most central Au+Au event Good E/p match for e/  separation

April 12, 2011Dr. Edward O’BrienDIS HCal improvement to Jet Energy Measurement

April 12, 2011Dr. Edward O’BrienDIS Capabilities of the Central Barrel Upgraded Central barrel expands PHENIX’s acceptance for many important HI signatures by over an order of magnitude This combined with RHIC II luminosities provides for a very large energy range for jet,  and  o measurements

April 12, 2011Dr. Edward O’BrienDIS Technologies Intermediate tracking layer – Si strip or GEM HCal – Fe or Pb Scintillator tile calorimeter Preshower – W- Si strips EMCal – Maybe reconfigured PHENIX PbScintillator – W-Scintillator – PbWO 4 RICH – Likely triple radiators: Aerogel + liquid radiators Forward Tracking – GEMs Solenoid – Superconducting Silicon VTX and Hadron Blind Detector EMCal MPC-EX R&D EMCal Muon Piston Calorimeter Aerogel +RICH Hadron Blind Detector PHENIX experience with similar technologies

April 12, 2011Dr. Edward O’BrienDIS Future Physics Program Next 5-6 years In depth investigation of sQGP energy-loss dynamics, especially heavy quark energy loss Accurate measure of  /s at RHIC. Separation of initial state effects from sQGP QCD critical point determination, if signature exists. Quark flavor-selected spin measurement through W- asymmetry. – Both polarized p+p and p+He 3 to get at the neutron constituents Continuation of  G program after RHIC luminosity upgrade – Is  G non-zero? Low x spin studies using HQs Drell Yan and transverse spin program 7-10 years Detailed energy loss dynamics studies using jets and dijet correlations sQGP thermalization mechanism Quasi-particles in sQGP, screening length, relevant strong coupling length scales Continuation of DY and transverse spin studies with higher sensitivity  G to low x using dijets and  -jet correlations 2020 and beyond (EIC era) Using e+p to measure polarized and unpolarized structure functions Nuclear pdfs Determining nuclear initial states (sQGP initial states) using e+A diffractive measurements and DV Compton scattering to map gluon and quark initial densities Follow-up on discoveries made from

April 12, 2011Dr. Edward O’BrienDIS Summary The PHENIX experiment is in its 11th year of operations and continues to maintain high rates of publications, citations and physics productivity. We just completed the largest upgrade installation since 2002 with the addition of the Si VTX, Muon Trigger, and DAQ Upgrade. – In addition the Forward Silicon (FVTX) will be installed during the 2011 RHIC shutdown The combination of capabilities added by VTX, FVTX, MuTrg, DAQ plus RHIC machine upgrades provides a robust physics program for PHENIX for the next 5-7 years The addition of hadronic calorimetry for jet physics together with a significantly enhanced forward spectrometer will provide capabilities currently missing in the RHIC program and enable critical physics questions to be addressed. The proposed PHENIX upgrade builds on existing subdetector components, utilizes the collaboration’s technical strengths, strongly coincides with our physics interest and addresses what are arguably the some of the most interesting questions in HI physics, proton spin and nuclear structure in the coming decade.

April 12, 2011Dr. Edward O’BrienDIS Back Up

April 12, 2011Dr. Edward O’BrienDIS The Upgrade Detector What remains: VTX and FVTX EMCal in Forward Arm DAQ Infrastructure (LV, HV, Safety…) What is new: Hadronic Calorimetry Preshower detector Additional tracking layer of Si at ~ 40cm 2T solenoid (R = cm) Barrel EMCal (maybe new) Forward Arm with RICH and GEM tracker Can be built incrementally EMCal HCal RICH

April 12, 2011Dr. Edward O’BrienDIS Quark and Anti-Quark Helicity Distributions from Inclusive A L e,μ in W-Production Large Q 2, knowledge of FFs not needed ab initio pQCD analysis of inclusive lepton A L DSSV analyzed MC data of 200 pb -1 and 800 pb -1 from STAR and PHENIX Significant improvement of knowledge with 200 pb -1 Courtesy Daniel De Florian

April 12, 2011Dr. Edward O’BrienDIS