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Welcome to the workshopon forward calorimetry

Richard Seto

Overview

FOrward CALorimeter

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Welcome! Overview of FOCAL Jan 19-Review recommendations Goals/purpose of workshop and agenda

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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

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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 xG x

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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

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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

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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

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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

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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

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Perfect space for FOCAL! (but tight!)

14 EM bricks14 HAD bricksHAD behind EM

FOCAL

40 cm from Vertex

20 cm of space

nosecone

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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?

12M

uon

trac

king

Muo

n tr

acki

ng

VTX & FVTX MPCMPC

-3 -2 -1 0 1 2 3 rapidity

cove

rage

2

EMC

EMC

FOCAL a large acceptance calorimeter

FOCALFOCAL

track

ing

track

ing

What’s missing? FORward CALorimetery

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reach in x2 for g(x) and GA(x)

log(x2)EMC+VTXEMC+VTX+FOCALEMC+VTX+FOCAL+MPC X2 10-3

2~s Q

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FOCAL Design

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Overall Detector – stack the bricks

“brick”

85 cm Note thisledge may not bein the final design

supertower

17 cm6cm

6cm

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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

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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

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Detection – how it works

Some detector performance examples

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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

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It’s a tracking device

vertex

EM0 EM1 EM2 A 10 GeV photon “track”

Pixel-like tracking:3 layers + vertexEach “hit” is the center of gravity of the cluster in the segmentIterative pattern recognition algorithm uses a parameterization of the shower shape for energy sharing among clusters in a segment and among tracks in the calorimeter.

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Energy Resolution (Geant4)

Excludes Stripsno sampling fraction correction

0.00+0.20/√E

New Geometry

adequate: we wanted ~ 0.25/√E

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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

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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

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Jan 19 – a review

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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.

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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

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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

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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.

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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!

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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

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Backup

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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

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occupancyAuAu(3.2)

cm #/cm2 #/cm2 #/cm2

*36/16 *36/128

R had tot pad Strips3 4 3 3 6 14 1.72.5 7 2 2 4 9 12 11.

3.7 1 2 4.5 .5

1.5 20 .2 .2 .4 .9 .111 36 .08 .08 .16 .36 .045

pp cm #/cm2 #/cm2 #/cm2

*36/16 *36/128

R had tot pad Strips3 4 2e-2 4e-2 .09 .012 11 3e-3 6e-3 .013 1.7e-31.5 19 1e-3 2e-3 .0045 6e-41 36 3e-4 6e-4 1e-3 1.6e-4

0

singe track 0

highenergyemshower

?

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35

CAD guidance (29-dec-08) p+p

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CAD guidance (29-dec-08) Au+Au

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38

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sum total over all years

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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

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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

xx

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

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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=