phenix p/d+a, e+a overview p,d,e+a workshop bnl, june 26, 2013 r. seto university of california,...
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PHENIX p/d+A, e+A overview
p,d,e+A WorkshopBNL, June 26, 2013
R. SetoUniversity of California, Riverside
2
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
3
s
Initial stateColor Glass Condensate?t=0.0 fm
Thermalized;Hydrodynamics;Flow
Pre-thermalization;Glasma?
Au+Au, Pb+Pb: sQGP. How is it born?
Δη
t
η
sQGP
t~0.6 fm
“Small” systems
1
4s
PHENIX (2011)PRL 107, 252301
4
p+Pb, d+Au
Initial stateColor Glass Condensate?t=0.0 fm
A Control and the initial state
t
η
PHENIX PRL 91, 072303 (2003)
PRL 107, 172301(2011)
QS
5
Initial stateColor Glass Condensate?t=0.0 fm
Δη
p+Pb, d+Au LHC: the ridge??
t
η
ATLAS PRL 110 182302 (2013)
0.5 4associatedTp
Y=“per trigger yield”
Central 2%
2<|Δη|<5
trig
assoc
Central 2%Periph 52%
?
6
p+Pb, d+Au PHENIX
arXiv 1303.1794
v2
Au+Au
PRL 105, 062301 (2010)
0-5%
0.25
d+Au
0.5<|Δη|<0.7
7
Mid-Forward Particle/Energy Correlations
3<|Δη|<4
8
3<|Δη|<4
9
Initial stateColor Glass Condensate?t=0.0 fm
Δη
p+Pb, d+Au
t
η
10
Δη
Initial state: Color Glass Condensate?t=0.0 fm
Pre-thermalization;Glasma?
p+Pb, d+Au Glasma? Long range rapidity Correlations
Hypothesis I: Initial state fluctuations “inflated” to long range correlations
t
η
Glasmat~0.6 fm
11
Δη
Initial stateColor Glass Condensate?t=0.0 fm
Pre-thermalizationGlasma?
p+Pb, d+Au Glasma? Long range rapidity Correlations
Hypothesis I: Initial state fluctuations “inflated” to long range correlations
t
η
Glasmat~0.6 fm
Δ ϕ
Atlas Data comparedTo Glasma modelQ0
2(proton)=0.168 GeV2
Dusling, VenugopalanarXiv:1302.7018 (2013)
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Δη
Initial stateColor Glass Condensate?t=0.0 fm
ThermalizedHydrodynamicsFlow: sQGP.
Pre-thermalization
p+Pb, d+Au Flow?
sQGP in small systems?
Hypothesis II: Flow (Hydro) In a thermalized sQGP
sQGP
t~0.6 fm
HydrodynamicCalculationsP. Bozek PRC 85, 014911
1
4s
13
Conclusions?
• None yet• Very interesting phenomena• More Experimental data/Theoretical work
needed
14
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 polarized p+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
InitialState?
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MPC-EX reconstruction of π0s and γdirect at forward rapidity
from low Q2 to kinematic limit
3.1<|η|<3.8
8 layer(4X0) Silicon minipad, Tungsten sandwich Preshower in front of PbWO4 MPC calorimeterarXiv:1301.1096
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How does it work?
MPC: Shower energyMPC-EX
40 GeV π0
Opening angleEnergy Sharing
γγ invariant mass
40 GeV single γ
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Projected γdir Measurement of nuclear gluon distribution as benchmark
Present limits
Projected90% CL
Nuclear Mod. Factor pAdirect
G ppdirect
xGR
A xG
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Polarized p+A Collisionsas a measurement of Qs
Kang, Yuan: PRD 84, 034019 (2011)
Single spin asymmetries can act as a probe of the saturation scale.
RL
RL
N PA
1
Right
Left
• Dependence of QsA on A, centrality• Combined with other measurements this can estimate Qsp
at pt <<Qsat
Large π SSAs seen at forward rapidityIn transversely polarized pp at RHIC
π
π
π
Spin Dependent Cross section
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Kang, Yuan: PRD 84, 034019 (2011)
Transversely polarizedproton
Collins FragmentationFunction
πk┴,π
P
sp
sq
A
q
This is one mechanism. Others:e.g. Sivers: see Boer et al. PRD 74, 074018Kang-Xiao arXiv 1212.4309Odderon (3 gluon)exchange: Yovchegov arXiv:1201.5890
2 2/
2
1( , ) Sk Q
FS
N x k eQ
CGC inspired k┴ dependent unintegrated Gluon distribution functionLow-x
Relative toQuark jet
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π0 in Polarized p+A as a tool to study Gluon saturation
2 1/3, ,sat A sat protonQ cA Q
pRight
Left
RL
RL
N PA
1
2 2 2
2 2
2/
2h sp
h sA
pA hP QspN
pp hN sAP Q
QAe
A Q
2, 1.0 0.5proton
sat gluonsQ GeV c
A
pT
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π0 in Polarized p+A as a tool to study Gluon saturation
Right
Left
2 2 2
2 2
2/
2h sp
h sA
pA hP QspN
pp hN sAP Q
QAe
A Q
2, 0.45 0.5proton
sat gluonsQ GeV c
RL
RL
N PA
1
2 1/3, ,sat A sat protonQ cA Q
p
A
pT
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π0 in Polarized p+A as a tool to study Gluon saturation
Right
Left
2 2 2
2 2
2/
2h sp
h sA
pA hP QspN
pp hN sAP Q
QAe
A Q
2, 1.0 1.0 (nuclear diluteness)proton
sat gluonsQ GeV c
RL
RL
N PA
1
2 1/3, ,sat A sat protonQ cA Q
p
A
pT
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THE LONGER TERM
sPHENIX, fsPHENIX, ePHENIX
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, pp equiv– 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 3024
sPHENIX
• Jets+heavy flavor in Heavy Ion Collisions – Replace central arms with hermetic detector– HCAL, EMCAL, Preshower, tracking w/solenoidal B
2015 incl MPC-EX 2019
25
arXiv:1207.6378
26
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
Jin Huang <[email protected]> 27Workshop on Forward upgrades
A detector concept – EIC collisions
p/A e-
Aerogel&
RICH
GEMStation4
EMCal
HCal
GEMStation2
z (cm)
R (cm)
HCal
EMCal& Preshower
GEMs
EMCal & Preshower
μ-TPC
DIRC
η~1
η~4
-1.2
R (cm)
GEMStation3
GEMsStation1
η~-1
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PHENIX+MPC-EX → sPHENIX→fsPHENIX→ePHENIX
GlasmasQGP?
e+p
e+A
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
– AN π0 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 spin29