1 eic ew meeting, w&m, va, may 2010 e.c. aschenauer
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FIRST THOUGHTS ABOUT EP/EA COLLISIONS AT PHENIX
EIC EW Meeting, W&M, VA, May 2010E.C. Aschenauer
EIC EW Meeting, W&M, VA, May 2010 2
Physics Topics
E.C. Aschenauer
unpolarised and polarised inclusive physics detect only the scattered lepton F2 and FL for proton and nuclei, g1 and g2 for proton / He-3
d2σempNC
dxdQ2 =2παem2 Y+
xQ4 (F2 −y2Y+
FL ±Y−Y+
xF3)
q(x, Q2 )+ q(x,Q2 ) g(x,Q2 ) q(x, Q2 )−q(x,Q2 )
antishadowing“sweet” spotR=1
shadowingLHC h=0RHIC h=3
Assumptions: 10GeV x 100GeV/n
√s=63GeV Ldt = 4/A fb-1
equiv to 3.8 1033 cm-2s-1
T=4weeks; DC:50% Detector: 100% efficient
Q2 up to kin. limit sx Statistical errors only
Note: L~1/A smearing effects can be significant
EIC EW Meeting, W&M, VA, May 2010 3
Physics Topics unpolarised and polarised inclusive physics
detect only the scattered lepton F2 and FL for proton and nuclei, g1 and g2 for proton / He-3
d2σempNC
dxdQ2 =2παem2 Y+
xQ4 (F2 −y2Y+
FL ±Y−Y+
xF3)
q(x, Q2 )+ q(x,Q2 ) g(x,Q2 ) q(x, Q2 )−q(x,Q2 )
Lets get a feeling for systematic uncertainties: 1% energy-to-energy normalization low detector smearing will be crucial
tracking vs. calorimetry 1 - 2% vs. 5 - 10%
FL for fixed electron energy (4GeV)and proton energies:50, 70, 100, 250 GeVLuminosity: 4fb-1 each setting
E.C. Aschenauer
EIC EW Meeting, W&M, VA, May 2010 4
Physics Topics unpolarised and polarised inclusive physics
detect only the scattered lepton F2 and FL for proton and nuclei, g1 and g2 for proton / He-3
d 2σdΩdE '
~LμνWμν
W μν =−gμνF1 −
pμ pν
νF2 +
iνε μνλσqλsσ g1 +
i
ν 2ε μνλσqλ (p⋅qsσ −s⋅qpσ )g2
Integrated Lumi: 5fb-
1
Same issues with detectorresolution as F2 and FL
in addition need to reduce systematics due to polarisation
E.C. Aschenauer
EIC EW Meeting, W&M, VA, May 2010 5
Kinematics
x
Q2
higher hadron energy at the same lepton beam energy allows access to lower x
higher lepton beam energy at the same hadron beam energy allows access to lower x
x =Q2
ys
Q2 =2EeEe'(1+cosθe')
E.C. Aschenauer
EIC EW Meeting, W&M, VA, May 2010 6
e’ Kinematics Lets concentrate on 4GeV lepton energy
electron beam “replaces” yellow hadron beamProton Energy
50 GeV 100 GeV 250 GeV
4x50
pe: 0-1 GeV pe: 1-2 GeV pe: 2-3 GeV pe: 3-4 GeV
e-p/A
180o 0o
No dependence on hadron beam energyQ2>0.1GeV2
4GeV >5o
10GeV >2o
20GeV >1o
E.C. Aschenauer
EIC EW Meeting, W&M, VA, May 2010 7
Hadron Kinematics
4x100
4x250
4x250
4x1004x50
4x50
E.C. Aschenauer
EIC EW Meeting, W&M, VA, May 2010 8
Diffractive Physics: p’ kinematics
4 x 100
t=(p4-p2)2 = 2[(mpin.mp
out)-(EinEout - pz
inpzout)]
4 x 50
4 x 50
4 x 250
?
Diffraction:
E.C. Aschenauer
EIC EW Meeting, W&M, VA, May 2010 9
Current PHENIX Detector at RHIC
MPC 3.1 < | h | < 3.9 2.5o < Q < 5.2o Muon Arms 1.2 < | h | < 2.4 South: 12o < Q < 37o
North: 10o < Q < 37o
Central Arms | h | < 0.35 60o < Q < 110o
e-
electrons will not make it to the south muon arm to much material
E.C. Aschenauer
EIC EW Meeting, W&M, VA, May 2010 10
What will the current PheniX see4x100
pe: 0-1 GeV pe: 1-2 GeV pe: 2-3 GeV pe: 3-4 GeV
4x100 4x100
Current PheniX detector not really useable for
DISacceptance not matched to DIS kinematics
E.C. Aschenauer
EIC EW Meeting, W&M, VA, May 2010 11
HCALEMCAL
Preshower
The new PheniX Spectrometer Coverage in |h| =< 4 (2o < q < 30o) 0.1 < Q2 < 100 (5o –
175o) need an open geometry detector planes for next decadal plan
replace current central detector with a new one covering |h| =< 1
60cm
2T SolenoidEMCAL
HCAL
Silicon TrackerVTX + 1 layer
Silicon TrackerFVTX
1.2 < h < 2.7 8o < q < 37o
North Muon Arm
RICH
68cm
IP
80cm
145cm
5o @ 2m 17.4 cm dy
E.C. Aschenauer
12
IR-Design
E.C. Aschenauer EIC EW Meeting, W&M, VA, May 2010
0.4
4 m
Q5D5
Q4
90 m
10 mrad 0.3
29 m
3.67 mrad
60 m10 20 30
0.1
88036 m
18.8 m
16.8 m
6.33 mrad
4 m
© D.Trbojevic
30 GeV e-
325 GeV p
Or 125 GeV/u ions
eRHIC - Geometry high-lumi IR with β*=5 cm, l*=4.5 mand 10 mrad crossing angle
m
EIC EW Meeting, W&M, VA, May 2010 13
What can new PheniX do PROs:
large coverage for scattered lepton can do inclusive ep/eA physics through all stages of eRHIC can do semi-inclusive and exclusive physics, which needs muon
and electron-id (i.e. J/psi)
CONs: momentum and angular resolution critical for precision
inclusive physics material budget in central detector is on the high side
IPs are better offset to the center of the detector for asymmetric colliders very difficult because of symmetric design of central detector
NO PID and Muon-arm on forward direction most of semi-inclusive and exclusive/diffractive physics not possible
High Luminosity IR design does not work with old and new PheniX
need to move focusing quads lower luminosity
Remarks / Questions: need to integrate 10mrad bend in design need to integrate a luminosity measurementE.C.
Aschenauer
Summary:
the new PheniX detector can make
important measurements
in ep/eA
Lets integrate it into the design
and the next decadal plan
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