1 Welcome to the workshop on 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 2012DM8Determine gluon densities at low x in cold nuclei via p+ Au or d + Au collisions.Required for direct photon 2013HP12Utilize 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-x Direct  2014DM10 (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 2015HP13 (new) Test unique QCD predictions for relation between single-transverse spin phenomena in p-p scattering and those observed in deep-inelastic lepton scattering New 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 transverse spin phenomena pA physics – nuclear gluon pdf

4 direct  jets –x resolution forward 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) x Saturation at low x xG(x) R G Pb pA physics – nuclear gluon pdf

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 x gluon = 0.02  0.3 direct  jets –x resolution forward η (low-x)  0 x RHIC range 0.05 · x · 0.2 small-x · x · 0.05  Longitudinal Spin  G,  g(x) : HP12 EXTEND MEASUREMENTS TO LOW x! Forward Measure x

6 direct  -jet  0 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 - shower large 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? leading EM 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 x 2  0 s forward  to reach low-x has large  coverage now what do we build?

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!) 14EM bricks 14 HAD bricks HAD behind EM FOCAL 40 cm from Vertex 20 cm of space nosecone

11 FOCAL Requirements Ability to measure photons and π 0 ’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 x 2 ~ Densest calorimeter -> Si W We wanted large  coverage what sort of coverage if we put a detector where the nosecones are?

12 Muon tracking VTX & FVTX MPC rapidity  coverage 2  EMC FOCAL a large acceptance calorimeter FOCAL tracking What’s missing?FORward CALorimetery

13 reach in x 2 for  g(x) and G A (x) log(x 2 ) EMC+VTX EMC+VTX+FOCAL EMC+VTX+FOCAL+MPC X 2  10 -3

14 FOCAL Design

15 Overall Detector – stack the bricks “brick” 85 cm Note this ledge may not be in the final design supertower 17 cm 6cm

16 Design Tungsten-Silicon Silicon “pads” 4 planes of x-y “strips” (8 physical planes) Particle Direction 4 mm W Supertower γ/π 0 Discriminator= EM0 EM1 EM2 segments= Pads Silicon Design Pads: 21 layers 535  m silicon 16 cells: 15.5mmx15.5mm X 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 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= 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 Strips no sampling fraction correction /√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 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   /  0 identification: single track  /  0 tested 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 0.2 FTE With *great* urgency: provide sufficient manpower Delta-G FTE) dAu 0.5 FTE) AuAu 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 Organization and planning Introductory talks the physics (groups) the hardware

31 Backup

32 Resolutions EM shower energy – 20%/  E angular – 6mr Jet angular resolution 60 pt=20 GeV PT jet angular resolution Full PISA simulation

33 occupancy AuAu(3.2)cm#/cm 2 *36/16*36/128  R  hadtotpadStrips ppcm#/cm 2 *36/16*36/128  R  hadtotpadStrips 342e-24e e-36e e e-32e e e-46e-41e-31.6e-4   0 singe track  0 high energy em shower ?

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= y=1-1.5 pt= y=1-1.5 pt= y=1-1.5  /  0 identification: pp 2 track  0 p T <5 GeV E=6-10 GeV pt= y=2-2.5 pt= y= pt= y=

41 x 2 resolution – no radiation Detector smearing only Note: radiative smearing is at least as big as detector smearing (use NNLO QCD) log(x 2 ) x2~ resolution 15% we will assume lowest x is x gluon can pick out regions of x2

42 Design (4 x-y planes) [backup] Silicon “pads” 4 planes of x-y “strips” (8 physical planes) Particle Direction 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/π 0 Discriminator= EM0 EM1 EM2 segments=