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1
Welcome to the workshopon forward calorimetry
Richard Seto
Overview
FOrward CALorimeter
2
Welcome!
Overview of FOCAL Jan 19-Review recommendations Goals/purpose of workshop and agenda
3
NSAC milestones – Physics Goals
Year # MileStone FOCAL
2012
DM8 Determine gluon densities at low x in cold nuclei via p+ Au or d + Au collisions.
Required for direct photon
2013
HP12 Utilize polarized proton collisions at center of mass energies of 200 and 500 GeV, in combination with global QCD analyses, to determine if gluons have appreciable polarization over any range of momentum fraction between 1 and 30% of the momentum of a polarized proton.
Low-xDirect
2014
DM10(new)
Measure jet and photon production and their correlations in A≈200 ion+ion collisions at energies from medium RHIC energies to the highest achievable energies at LHC.DM10 captures efforts to measure jet correlations over a span of energies at RHIC and a new program using the CERN Large Hadron Collider and its ALICE, ATLAS and CMS detectors.
Marginal without FOCAL
2015
HP13 (new)
Test unique QCD predictions for relation between single-transverse spin phenomena in p-p scattering and those observed in deep-inelastic lepton scatteringNew Milestone HP13 reflects the intense activity and theoretical breakthroughs of recent years in understanding the parton distribution functions accessed in spin asymmetries for hard-scattering reactions involving a transversely polarized proton. This leads to new experimental opportunities to test all our concepts for analyzing hard scattering with perturbative QCD.
Required
G
-Jet AuAu
transversespin phenomena
pA physics – nuclear gluon pdf
4
direct jets –x resolutionforward η(low-x)
Nuclear Gluon PDF’s : DM8 Look for saturation
effects at low x Measure initial state
of Heavy Ion Collision
measure gluon PDF’s in nuclei! (DM8)1 ( )T Jetp
x e es
xSaturation at low x
xG(x)
RGPb
pA physics – nuclear gluon pdf
( )
( )Pb
p
G x
G x
5
g(x) very small at medium x (even compared to GRSV or DNS)
best fit has a node at x ~ 0.1 huge uncertainties at small x
DSSV finds
Current data is sensitive to G for xgluon= 0.020.3
direct jets –x resolutionforward η(low-x)0 0
x RHIC range0.05· x · 0.2
small-x0.001· x · 0.05
Longitudinal Spin G, g(x) : HP12
EXTEND MEASUREMENTS TO LOW x!Forward
Measure x
6
direct -jet0
forward η(low-x)large η coverage
Major new Thrust Transverse Spin Phenomena: HP13
use -jet to measure Sivers
determination of the process dependence of the Sivers effect in +jet events
So what does Sivers tell us about orbital angular momentum?
Sivers
7
EM - showerlarge η coverage
Jet correlations in AuAu
Correlations with jets in heavy Ion collisions: DM10
Study the medium via long range correlations with jets
are these correlations from a response by the medium?
leadingEM shower
?
for example
“ridge”
“jet”
STAR Preliminary
8
To meet these goals we must have a detector that measures:
direct and electromagnetic showers
jet angles to obtain x2
0 s forward to reach low-x has large coverage
now what do we build?
1 ( )T Jetpx e e
s
9
Schematic of PHENIX
Central Arms ||<0.3 Tracking PbSc/PbGl(EMC) PID VTX to come
MPC 3<||<4
Muon arms 1.1<||<2.4 magnet tracking -ID FVTX to come
central magnet
calorimetry
10
Perfect space for FOCAL! (but tight!)
14 EM bricks14 HAD bricksHAD behind EM
FOCAL
40 cm from Vertex
20 cm of space
nosecone
11
FOCAL Requirements Ability to measure photons and π0’s to 30
GeV Energy resolution < 25%/E Compact (20 cm depth) Ability to identify EM/hadronic activity Jet angular measurement High granularity ~ similar to central arms small mollier radius ~1.4 cm large acceptance – rapidity coverage x2 ~
0.001 Densest calorimeter -> Si W
We wanted large coveragewhat sort of coverage if we put a detector where the nosecones are?
12
Mu
on
tra
ckin
g
Mu
on
tra
ckin
g
VTX & FVTX MP
C
MP
C
-3 -2 -1 0 1 2 3 rapidity
cove
rage
2
EM
CE
MC
FOCAL a large acceptance calorimeter
FOCALFOCAL
trac
kin
g
trac
kin
g
What’s missing? FORward CALorimetery
13
reach in x2 for g(x) and GA(x)
log(x2)EMC+VTXEMC+VTX+FOCALEMC+VTX+FOCAL+MPC X2 10-3
2~s Q
14
FOCAL Design
15
Overall Detector – stack the bricks
“brick”
85 cm Note thisledge may not bein the final design
supertower
17 cm6cm
6cm
16
Design Tungsten-Silicon
Silicon “pads”4 planes of x-y “strips” (8 physical planes)
ParticleDirection
4 mm W
Supertower
γ/π0 Discriminator=EM0 EM1 EM2segments=
Pads SiliconDesign
Pads: 21 layers 535 m silicon 16 cells:
15.5mmx15.5mmX and Y Strips: 4 layers
x-y high resolution strip planes
128 strips: 6.2cmx0.5mm
6cm
17
Vital statistics ~17 cm in length 22 X0 ~ 0.9 Strips – read out by SVX-4
8 layer *128 strips=1024 strips/super-tower 1024 strips/super-tower*160 super-towers/side = 163,840 strips/side 163840 strips/side (1detector/128 strips) = 1280 Strip
Detectors/side 163,840 strips /(128 channels/chip)= 1280 chips/side
Pads – read out by ADC– 3 longitudinal readouts 160 supertowers/side*21 detectors/supertower=
3360 Si pad detectors/side 3360 detector*16channels/detector= 53760 pads/side
readout channels (pads) 160 supe-rtowers/side *16 pads/tower*3 towers =7680 readouts/side
Bricks 2x4 supertowers: 4 2x6 supertowers: 6 2x7 supertowers: 4
EM0= /0, EM1, EM2 segments
18
Detection – how it works
Some detector performance examples
19
Status of simulations Stand alone done w/ GEANT3/G4 to study
/0 separation, single track 0 (G4) EM shower energy/angle resolutions (G4)
Full PISA jet resolution (G3/PISA) 2 track 0 (G3/PISA)
Several levels Statistical errors, backgrounds, resolutions folded into
Pythia level calculations Full PISA simulation using old configuration
Transverse spin physics – task force formed – simulations in progress (early step is to put models etc into simulations)
*PISA – PHENIX Geant3 simulation
20
It’s a tracking device
vertex
EM0 EM1 EM2 A 10 GeV photon “track”
Pixel-like tracking:3 layers + vertex
Each “hit” is the center of gravity of the cluster in the segment
Iterative pattern recognition algorithm uses a parameterization of the shower shape for energy sharing among clusters in a segment and among tracks in the calorimeter.
21
Energy Resolution (Geant4)
Excludes Stripsno sampling fraction correction
0.00+0.20/√E
New Geometry
adequate: we wanted ~ 0.25/√E
22
X-view
Y-view
50 GeV pi0
4-x, 2x
4-y, 3y
/0 identification:
Single track /0
for pt>5 GeV showers overlap use x/y + vertex
to get opening angle
Energy from Calorimeter
Energy Asymmetry – assume 50-50 split as a first algorithm
invariant mass
23
10 GeV ~1.65 (Geant4-pp events)
Fake reconstruction: 20%Real 0 reconstruction: 50-60%
Real reconstruction: ~ 60%Fake 0 reconstruction ~ 5%
Assumed 0 region Assumed region
0
/0 identification: single track /0tested at various energies and angles, so far at pp multiplicities
24
Jan 19 – a review
25
Jan 19 – review Members
M. Grosse-Perdekamp (chair), Elke Aschenauer, Christine Aidala, Mike Leitch, Glenn Young
charge assess the state of the plans for the FOCAL
physics justification - the potential impact of the physics program
technical design? adequate for physics objectives? recommendations important guide for
a detector proposal external project review Timescale : in 9 to 12 months.
26
Recommendations – from the exec summary
focus on the first three milestones for FOCAL proposal (dAu, Delta G, transverse physics) measure parton distribution functions in
nuclei at low x physics critically depends on its ability
to reconstruct in p+p and d+Au
27
Recommendations – physics groups significant effort needed on simulations form 4 FOCAL physics study groups (give freedom to
leaders) d-A heavy ion Delta-G transverse spin
each group requires an experienced group leader @ 0.2 FTE With *great* urgency: provide sufficient manpower Delta-G
(1 @0.5 FTE) dAu (5 @ 0.5 FTE) AuAu (2 @0.5 FTE) transverse - group formed and working
proposal ready by September
28
recommended schedule April, 2009
to PM: schedule and leadership + manpower for the physics study groups. (initial org chart)
to PM: organizational structure for the hardware side of the project (sub tasks, sub task leaders, institutional responsibilities)
Review of FEE, DAQ & trigger (TBD – in sync with ongoing run) May, 2009:
to DC: FOCAL technology and design choice. simulation plans, goals, manpower and structure of physics study groups.
PM: review overall organizational structure (sub-tasks, sub-task managers, institutional responsibilities, FTE available, FTE needed etc.)
June, 2009: PHENIX internal FOCAL budget review. workshop on Forward Physics with the PHENIX detector upgrades.
(this meeting and July Collab meeting) July, 2009: FOCAL collaboration meeting: beam test results,
simulation progress, simulation tasks left open? writing assignments.
September, 2009: proposal to PHENIX DC&EC. October, 2009: External review.
29
Goals for workshop Physics
Solidify, clarify, and make more specific physics goals for proposal
Situation now Theory status Next measurements needed How can the FOCAL contribute? What is the competition? What simulations needed?
introduce simulations to everyone Fully determine physics groups
Who will do what Discuss hardware interests Set goals for funding strategy
Be thinking 10 years!
30
Agenda 9:00-9:30 Welcome/intro to FOCAL –Rich Seto Introductory Talks
9:30-10:00 Questions in Spin Physics - Elke Aschenauer 10:00-10:30 Transverse Physics theory - Andreas Metz
Topics in Forward Physics 10:30-11:00 Measuring Delta G - Mickey Chiu
11:00-11:15 Break 11:15-11:45 Transverse physics - John Lajoie 11:45-12:15 pA - Mike Leitch 12:15-12:45 AuAu - Justin Franz
12:45-1:45 Lunch Afternoon-focus on PHENIX/FOCAL 1:45-2:15 Status of FOCAL hardware - Edouard Kistenev 2:15-2:45 Triggering and Electronics - Andrey Sukhanov Simulations
2:45-3:15 Questions to attack - Yongil Kwon 3:15-3:45 Status - Ondrej Chvala 3:45-4:00 Spin readiness - Richard Hollis
4:00-4:15 Break 4:15-4:30 Funding/Schedule - Rich Seto 4:30-5:30 Discussion
Organizationand planning
Introductory talks
the physics(groups)
the hardware
31
Backup
32
Resolutions
EM shower energy – 20%/E angular – 6mr
Jet angular resolution 60 mr @ pt=20 GeV
PT
jet angularresolution
( )JetTgluon
px e e
s
Full PISAsimulation
33
occupancyAuAu(3.2)
cm #/cm2 #/cm2 #/cm2
*36/16 *36/128
R had tot pad Strips
3 4 3 3 6 14 1.7
2.5 7 2 2 4 9 1
2 11.3
.7 1 2 4.5 .5
1.5 20 .2 .2 .4 .9 .11
1 36 .08 .08 .16 .36 .045
pp cm #/cm2 #/cm2 #/cm2
*36/16 *36/128
R had tot pad Strips
3 4 2e-2 4e-2 .09 .01
2 11 3e-3 6e-3 .013 1.7e-3
1.5 19 1e-3 2e-3 .0045 6e-4
1 36 3e-4 6e-4 1e-3 1.6e-4
0
singe track 0
highenergyemshower
?
34
35
CAD guidance (29-dec-08) p+p
36
CAD guidance (29-dec-08) Au+Au
37
38
39
sum total over all years
40
pt=2.-2.5y=1-1.5 pt=4.-4.5
y=1-1.5
pt=1.-1.5y=1-1.5
/0 identification: pp 2 track 0 pT<5 GeV
E=6-10 GeV
pt=0.5-1.0y=2-2.5pt=0.5-1.0
y=1.5-2.0
pt=1.5-2.0y=1.5-2.0
41
x2 resolution – no radiationDetector smearing only
Note: radiative smearingis at least as big as detectorsmearing(use NNLO QCD)
log(x2)
x2~ resolution 15%
2
2
x
x
2 2/x x
1
2
( )
( )
T Jet
T Jet
px e e
sp
x e es
we will assume lowest x is xgluon
can pick out regions of x2
42
Design (4 x-y planes) [backup]
Silicon “pads”4 planes of x-y “strips” (8 physical planes)
ParticleDirection
EM0= /0, EM1, EM2 segments, leaves 4-5 cm no room for hadronic segment
22 X0 0.9 (originally NCC was 14 X0 +28 X0 (HAD) 1.4)
4 mm W
old “NCC”
Supertower
γ/π0 Discriminator=EM0 EM1 EM2segments=
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