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PHENIX p/d+A , e+A overview. p,d,e+A Workshop BNL, June 26, 2013 R. Seto University of California, Riverside. Outline. The present: Setting the stage – Old and New PHENIX results The immediate future MPC-EX: direct photons and π 0 s at high η in p+A , H 3 +Au
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PHENIX p/d+A, e+A overview p,d,e+AWorkshop BNL, June 26, 2013 R. Seto University of California, Riverside
Outline • The present: Setting the stage – Old and New PHENIX results • The immediate future • MPC-EX: • direct photons and π0s at high η in p+A, H3+Au • Further in the future (brief, covered by J. Huang, workshop 2- forward upgrades) • fSPHENIX • ePHENIX
Au+Au, Pb+Pb: sQGP. How is it born? Δη s Thermalized; Hydrodynamics; Flow sQGP t~0.6 fm t Pre-thermalization; Glasma? η Initial state Color Glass Condensate? t=0.0 fm PHENIX (2011) PRL 107, 252301 “Small” systems
p+Pb, d+Au A Control and the initial state PHENIX PRL 91, 072303 (2003) t η QS Initial state Color Glass Condensate? t=0.0 fm PRL 107, 172301(2011)
p+Pb, d+Au LHC: the ridge?? Central 2% trig assoc Δη ? Y=“per trigger yield” Central 2% Periph 52% t η Initial state Color Glass Condensate? t=0.0 fm 2<|Δη|<5 ATLAS PRL 110 182302 (2013)
p+Pb, d+Au PHENIX 0.25 Au+Au 0-5% PRL 105, 062301 (2010) v2 d+Au 0.5<|Δη|<0.7 arXiv1303.1794
p+Pb, d+Au Δη t η Initial state Color Glass Condensate? t=0.0 fm
p+Pb, d+Au Glasma? Long range rapidity Correlations Δη t~0.6 fm Glasma t Pre-thermalization; Glasma? η Initial state: Color Glass Condensate? t=0.0 fm Hypothesis I: Initial state fluctuations “inflated” to long range correlations
p+Pb, d+Au Glasma? Long range rapidity Correlations Δη Atlas Data compared To Glasma model Q02(proton)=0.168 GeV2 Dusling, Venugopalan arXiv:1302.7018 (2013) t~0.6 fm Glasma t Pre-thermalization Glasma? η Initial state Color Glass Condensate? t=0.0 fm Δ ϕ Hypothesis I: Initial state fluctuations “inflated” to long range correlations
p+Pb, d+Au Flow? sQGP in small systems? Δη Thermalized Hydrodynamics Flow: sQGP. sQGP t~0.6 fm Pre-thermalization Hydrodynamic Calculations P. Bozek PRC 85, 014911 Initial state Color Glass Condensate? t=0.0 fm Hypothesis II: Flow (Hydro) In a thermalized sQGP
Conclusions? • None yet • Very interesting phenomena • More Experimental data/Theoretical work needed
The Immediate future (p+A – run 15): MPC-EX upgrade to PHENIX • How do gluons behave at very high density (i.e. low-x) • What is the initial condition for formation of the sQGP? • Present ideas: CGC, Modified Structure functions, shadowing • RG in p+A • AN in polarizedp+A as a measure of QS • What is the origin of long range rapidity correlations in small systems? • controlling the geometry • p+A (Au, Cu, Si, C) , He3+Au • Present ideas: the Glasma, Flow in small systems Initial State?
MPC-EX reconstruction of π0s and γdirect at forward rapidityfrom low Q2to kinematic limit 3.1<|η|<3.8 8 layer(4X0) Silicon minipad, Tungsten sandwich Preshower in front of PbWO4 MPC calorimeter arXiv:1301.1096
How does it work? MPC: Shower energy MPC-EX γγ invariant mass Opening angle Energy Sharing 40 GeV single γ 40 GeV π0
Projected γdir Measurement of nuclear gluon distribution as benchmark Projected 90% CL Present limits
Polarizedp+A Collisionsas a measurement of Qs Large π SSAs seen at forward rapidity In transversely polarized pp at RHIC Left at pt <<Qsat Right π π π Single spin asymmetries can act as a probe of the saturation scale. Kang, Yuan: PRD 84, 034019 (2011) • Dependence of QsAon A, centrality • Combined with other measurements this can estimate Qsp
Spin Dependent Cross section Kang, Yuan: PRD 84, 034019 (2011) A sp Relative to Quark jet CGC inspired k┴ dependent unintegrated Gluon distribution function Low-x Transversely polarized proton P sq q k┴,π π Collins Fragmentation Function This is one mechanism. Others: e.g. Sivers: see Boer et al. PRD 74, 074018 Kang-Xiao arXiv 1212.4309 Odderon (3 gluon)exchange: YovchegovarXiv:1201.5890
π0 in Polarized p+A as a tool to study Gluon saturation Left p Right A pT
π0 in Polarized p+A as a tool to study Gluon saturation Left Right A p pT
π0 in Polarized p+A as a tool to study Gluon saturation Left Right A p pT
sPHENIX, fsPHENIX, ePHENIX The longer term
ePHENIX LOI - Charge • Plans to upgrade/reconfigure PHENX to form a first generation eRHIC detector • Important part of BNL’s strategic plan for LRP • Plan for machine: • 10x100 eA @ L=6×1032 cm-2 s-1, ppequiv • 10 x255 (ep) @ L= 1033 cm-2 s-1 • Physics reach ala EIC white paper • Technical detail • Sufficient to provide a preliminary cost estimate • Rough construction schedule • Due date: Sept 30
sPHENIX • Jets+heavy flavor in Heavy Ion Collisions • Replace central arms with hermetic detector • HCAL, EMCAL, Preshower, tracking w/solenoidal B arXiv:1207.6378 2015 incl MPC-EX 2019
PHENIX (2013) • fsPHENIX • Physics • Transverse spin of proton • p+A studies (e.g. G1 , G2) • Heavy ions under study • Add forward arm • EMCAL, HCAL • Tracking: GEMS+Bfield • PID: RICH • ePHENIX • Physics • Nucleon spin structure (ΔG) • TMD, motion of confined partons • Parton imaging (Lum?) • Gluon saturation – diffractive events • Additional detectors • EMCAL in electron direction • DIRC in central ARMS • Replace central tracking with TPC or GEMs • Roman Pots? Details in Workshop 2: Jin Huang ~2025
A detector concept – EIC collisions η~1 R (cm) R (cm) HCal η~-1 HCal EMCal -1.2 Aerogel & RICH EMCal & Preshower EMCal & Preshower μ-TPC η~4 GEM Station2 z (cm) GEMs GEMs Station1 GEM Station3 GEM Station4 DIRC p/A e- Jin Huang <jhuang@bnl.gov>
PHENIX+MPC-EX → sPHENIX→fsPHENIX→ePHENIX Glasma sQGP? e+A e+p
Conclusions • “small” systems (p/d/He3+A) are exhibiting exciting new phenomena • Study of initial state • New ideas • Study of pre-thermalized state (GLASMA) • Perhaps study of sQGP in small systems • MPC-EX– new tool for study of (p/d/He3+A) • Gluon “suppression” at low-x via direct photons • ANπ0 in p+A as a measurement of QS • PHENIX→sPHENIX→fsPHENIX→ePHENIX • Evolutionary program for a study of the sQGP, Cold nuclear matter (saturation), and proton spin