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Introduction to Large/Huge Detector study

Introduction to Large/Huge Detector study. 10. Nov. 2004 @Kick-off meeting in 7 th ACFA LCWS in Taipei Y. Sugimoto KEK. Organization/Schedule.

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Introduction to Large/Huge Detector study

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  1. Introduction to Large/Huge Detector study 10. Nov. 2004 @Kick-off meeting in 7th ACFA LCWS in Taipei Y. Sugimoto KEK

  2. Organization/Schedule • None of SiD, Middle (TESLA), Large/Huge detector study group is a “Collaboration” in HEP sense. You can contribute to more than one study group. The tails of 3 gaussian peaks overlap with each other. • The study groups should be international (World-Wide Study) • Actually, inter-regional detector R&D collaborations (Horizontal collaborations, such as LC-TPC, CALICE, SiLC) can contribute to two or three study groups • Milestone: • Detector cost estimation by WWS costing panel at the end of 2005 • We hope the concept will survive until CDR (2007?) and TDR (2009?) • In a shorter range, we should present study results at LCWS2005 in Mar. at SLAC and Snowmass workshop in Aug.2005.

  3. Large/Huge detector concept • GLC detector as a starting point • Optimization mainly for PFA • Larger main tracker outer radius/ECAL inner radius • Larger Z position of EC CAL inner surface • Longer tracker/solenoid • Keep B field 3T (Stored EVTX(beam b.g.)/TPC(duffusion) resolution) • Re-consider the optimum sub-detector technologies based on the recent progresses • GLC Detector: Baseline detector (Minimum performance) Large/Huge Detector: State-of-art detector (Performance to get maximum physics output), backed up with simulation studies and detector R&D (anticipated in near future)

  4. Simulation study • Select minimum set of physics processes without duplication of final-state topology for the detector benchmark • For the moment, the topology up to 4-fermion final state with and without missing energy should be considered • There are two types of detector performances: • Process-dependent: Detector performance can be determined only when the physics process is specified. It affects the physics output, of course. • c- and b- tagging efficiency • Jet energy resolution • Process-independent: Detector performance is rather independent of process, but affects physics output • Pt resolution • Particle ID capability (K/p, m) • Minimum veto angle • Anything else?

  5. Simulation study • Other basic simulations • Detector full simulation specific to each sub-detector or combination of sub-detectors, but rather independent of physics processes. For example; • Tracking efficiency of vertex detector with beam background • Effect of tail catcher on the neutral hadron E resolution • Effect of two-photon background on the TPC resolution • Pt resolution v.s. number of sampling • The results of these simulations become inputs to or bases of the benchmark simulations

  6. ECAL HCAL Main tracker Solenoid magnet Si inner tracker Vertex detector Si pair monitor Muon system Si outer tracker Si endcap tracker Si forward disks Forward calorimeter Beam calorimeter PID DAQ system/Trigger(?) Detector R&D

  7. Summary • Too many study issues to be summarized as an introduction • A lot of jobs including clarification of physics requirements, detector full/quick simulation, and detector R&D are awaiting us • Defining the jobs may be the first job to be done

  8. Backup slides

  9. Detector components • EM Calorimeter • Small Rmeff  • W radiator • Make gaps as small as possible • Small segmentation : sseg < Rmeff • Hadron Calorimeter • Options • Absorber: Pb or Fe ? • Sensor: Scintillator or GEM ? • Digital or not digital ? • Tail catcher behind solenoid needed? • Choice of calorimeter options depends on the results of future detector R&D and detector simulation

  10. Detector components • Main tracker • TPC is a natural solution for the Large tracker • Positive ion feedback (2-g background) ? • Study of gas with small diffusion • Small-cell jet chamber as an option (End plate would be much thicker than TPC) • Solenoid magnet • Field uniformity in a large tracking volume • Is 2mm limit really needed? (TESLA TDR)

  11. Detector components • Muon system • No serious study for GLD so far • Design of muon system is indispensable for the solenoid/iron-yoke design, which takes large fraction of the total cost • How many layers? How thick? Which detector option? • Si inner/outer(?) tracker • Time stamping capability (separation of bunches) • High resolution Si strip det. improves momentum resolution • Z-measurement needed? • Si endcap tracker • Improves momentum resolution in the end-cap region where main tracker coverage is limited SIT: s=7mm, 3 layers VTX: s=3mm, 5 layers

  12. Detector components • Si forward disks / Forward Calorimeter • Tracking down to cosq=0.99 • Luminosity measurement • What is the beam background environment? • Beam calorimeter • Not considered in GLC detector • At ILC, background is 1/200. Need serious consideration • Careful design needed not to make back-splash to VTX • Minimum veto angle ~5mrad (?)  Physics • Crossing angle? • Si pair monitor • Measure beam profile from r-phi distribution of pair-background • Radiation-hard Si detector (Si 3D-pixel) • What happens if crossing angle is 24mrad?

  13. Vertex Detector Relatively low B-field of Large/Huge detector requires larger radius of the innermost layer Rmin (pair background) Detailed simulation of background (pair b.g. and synchrotron b.g. ) is necessary to determine Rmin and beam pipe radius R&D for thin wafer is very important to compensate for the degradation of I.P. resolution atlow momentum due to large Rmin TOF (?) K-p separation by dE/dx of TPC has a gap in 0.9–2 GeV/c TOF system with s=100ps can fill up the gap 1st layer of ECAL or additional detector ? What is the physics case? Detector components

  14. History of ACFA detector study • 1992 Dec. “JLC-I” report (JLC Detector) • 2T solenoid, R=4.5m • Compensating EM- and H-CAL, 2.5<R<4.0m • Small-cell Jet chamber, 0.45<R<2.3m, L=4.6m • 2001 Nov. “ACFA report” • 2003 Sep. “GLC report” (GLC Detector) • 3T solenoid, R=4m: Pair B.G. suppression • Compensating EM- and H-CAL, 1.6<R<3.4m • Small cell Jet chamber, 0.45<R<1.55m, L=3.1m ( Keep ptmin same as before) Degraded pt res. • 2004 Aug. ITRP technology choice • Good chance to re-start a new detector optimization study • Regional study  Inter-regional (world-wide) study • Milestone: Detector cost estimation at the end of 2005

  15. Large/Huge detector study so far • Actually, discussion on Large/Huge detector study has started before the ITRP decision • Started discussionafter LCWS2004 • Brief presentation at Victoria US WS (Jul.2004) • Presentation at Durham ECFA WS (Sep.2004) • Detector full simulator (JUPITER) construction on going • Discussion on the key components has started still earlier • TPC R&D for GLC detector started in 2003 • R&D for the calorimeter of GLC detector optimized for PFA (digital calorimeter) has proposed in Aug. 2003

  16. A possible modification from GLC detector model • Larger Rmax (1.552.0m) of the tracker and Rin (1.62.1m) of ECAL • TPC would be a natural solution for such a large tracker • Keep solenoid radius same:  Somewhat thinner CAL (but still 6l), but does it matter? • Use W instead of Pb for ECAL absorber • Effective Rm: 25.5mm  16.2mm (2.5mm W / 2.0mm Gap) • Small segmentation by Si pad layers or scintillator-strip layers • Put EC CAL at larger Z (2.05m2.8m)  Longer Solenoid • Preferable for B-field uniformity if TPC is used • It is preferable Zpole-tip < l* (4.3m?) both for neutron b.g. and QC support (l* :distance between IP and QC1)

  17. A possible modification from GLC detector model • New faces • Si Endcap Tracker • Si Outer Tracker • Beam Calorimeter • TOF

  18. Basic design concept • Performance goal (common to all det. concepts) • Vertex Detector: • Tracking: • Jet energy res.:  Detector optimized for Particle Flow Algorithm (PFA) • Large/Huge detector concept • GLC detector as a starting point • Move inner surface of ECAL outwards to optimize for PFA • Larger tracker to improve dpt/pt2 • Re-consider the optimum sub-detector technologies based on the recent progresses

  19. Optimization for PFA • Jet energy resolution • sjet2 = sch2 + sg2 + snh2 + sconfusion2 + sthreashold2 • Perfectparticleseparation: • Charged-g/nh separation • Confusion of g/nh shower with charged particles is the source of sconfusion  Separation between charged particle and g/nh shower is important • Charged particles should be spread out by B field • Lateral size of EM shower of g should be as small as possible ( ~ Rmeffective: effective Moliere length) • Tracking capability for shower particles in HCAL is a very attractive option  Digital HCAL

  20. Optimization for PFA • Figure of merit (ECAL): • Barrel: B Rin2/ Rmeffective • Endcap: B Z2/ Rmeffective Rin : Inner radius of Barrel ECAL Z : Z of EC ECAL front face (Actually, it is not so simple. Even with B=0, photon energy inside a certain distance from a charged track scales as ~Rin2) • Different approaches • B Rin2 : SiD • B Rin2 : TESLA • BRin2 : Large/Huge Detector

  21. Effective Moliere Length xg xa Effective Moliere Length = Rm(1+xg/xa) Gap : Sensor + R.O. elec + etc. Absorber W : Rm ~ 9mm Pb : Rm ~ 16mm

  22. Central Tracker • Figure of merit: n is proportional to L if sampling pitch is constant 

  23. Merits and demerits of Large/Huge detector • Merits • Advantage for PFA • Better pt and dE/dx resolution for the main tracker • Higher efficiency for long lived neutral particles (Ks, L, and unknown new particles) • Demerits • Cost ? – but it can be recovered by • Lower B field of 3T (Less stored energy) • Inexpensive option for ECAL (e.g. scintillator) • Vertex resolution for low momentum particles • Lower B requires larger Rmin of VTX because of beam background • d(IP)~5  10/(pbsin3/2q) mm is still achievable using wafers of ~50mm thick

  24. Comparison of parameters [1] GLD is a tentative name of the Large/Huge detector model. All parameters are tentative.

  25. Comparison of parameters

  26. Detector size • EM Calorimeter • Area of EM CAL (Barrel + Endcap) • SiD: ~40 m2 / layer • TESLA: ~80 m2 / layer • GLD: ~ 100 m2 / layer • (JLC: ~130 m2 / layer)

  27. Global geometry (All parameters are tentative)

  28. Global geometry

  29. Global geometry GLD is smaller than CMS “Large” is smaller than “Compact” 

  30. Detector components • TOF (Cont.) Assumptions: d(TOF)=100ps L=2.1m d(dE/dx)=4.5% K-p Separation (s) Momentum (GeV/c)

  31. Full Simulator • Installation of a new geometry into a full simulator “JUPITER” is under way

  32. Charged – g separation • Simulation by A. Miyamoto • Events are generated by Pythia6.2, simulated by Quick Simulator • Particle positions at the entrance of EM-CAL • Advantage of Large/Huge detector is confirmed • Inconsistent with J.C.B’s result  need more investigation F dcut

  33. Charged – g separation • Simulation by J.C. Brient (LCWS2004) e+e-  ZH  jets at Ecm=500GeV SD (6T) TESLA (4T)

  34. Magnet • ANSYS calculation by H.Yamaoka • Field uniformity in tracking region is OK • Geometry of muon detector is tentative. More realistic input is necessary

  35. Other studies • See presentations in parallel sessions and http://ilcphys.kek.jp/

  36. Summary • Optimization study of Large/Huge detector concept has just started • GLC detector is the starting point of the Large/Huge detector, but its geometry and sub-detector technologies will be largely modified • A key concept of Large/Huge detector is optimization for PFA • A milestone of this study is the detector cost estimation scheduled at the end of 2005. A firm report backed up with simulation studies and detector R&D should be written • A lot of jobs including clarification of physics requirements, detector full/quick simulation, and detector R&D are awaiting us • Please join the Kick-off meeting: Date: Nov. 10 Time: 17:30 - 19:30 Place: Room 204

  37. Pair background track density • Beam Calorimeter is placed in the high background region Same sign Opposite sign GLC Parameter, B=4T by T.Aso

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