1. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop1 Overview of LC Detectors Mark Oreglia, University of Chicago Outline: Physics drivers The TESLA-NA large design The Silicon Detector concept The Global Large Detector Thanks to: Bambade, Barklow, Behnke, Brau, Breidenbach, Damerell, Miller, Ronan, Schumacher, Sugimoto, Torrence, Woods, …

2. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop2 3 Archetype Physics Topics Light Higgs -- tracker –Best recoil mass resolution in Z-> dileptons Strong EWSB -- calorimeter –Important to look at WW scattering –W/Z jet separation crucial Some SUSY scenarios -- hermeticity –Cosmology “benchmarks” summarized: –“bulk” ->  annihilation -> smuon/selectron –“coannihilation” ->  s  au annihil. -> staus –Low angle backgrounds

3. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop3 Momentum Resolution e + e -  ZH  ll  X Golden physics channel!  (1/p) = 7 x 10 -5 /GeV 1/10 LEP !!! goal:  M  <0.1x      dominated by beamstrahlung

4. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop4 Impact Parameter  d= 5  m  10/p(GeV)  m 1/3 SLD !!! excellent flavor tagging capabilities for charm and bottom quarks –Need exceptional tagging for reducing combinatorial background in multi-jets... –Charge assignment –Asymmetry measurements –(measurement of Higgs BRs not so sensitive!) The big question: inner VTX radius –No simple answer – physics reach gains with lever arm and background suppresion, esp low momentum particles –… thus, low MS, small radius is essential –Needs more validation, but we are talking 1.5 cm radius! –Instrument lifetime issue Here we need you to tell us what is possible

5. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop5 (Jet) Energy Resolution  E/E = 0.3/  E(GeV) <1/2 LEP !!!  M Dijet ~  Z/W separation between e + e -  WW  qqqq and e + e -  ZZ  qqqq

6. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop6 Particle Flow reconstruction of multijet final states e+e-   H+H-  tbtb  bqqb bqqb Emphasis on combined systems now System compataibility means fine granularity in calorimeters (1 cm 2 !!!) Digital mode possible, if backgrounds controllable

7. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop7 Hermeticity hermetic down to  = 5 mrad Important physics with missing energy topologies (SUSY, extra-dim, Higgs,...) Background issues –Ability to veto low-p T particles –Crossing angle optimization Excellent physics motivation: SUSY-stau –DeRoeck’s talk here –Bambade & Lohman in Forward Region session

8. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop8 IR-Related Issues Good measurements in the low-angle region –Need to make p T cuts for physics analyses –Need to mask and reduce occupancies in low angle region –Need convincing? See Bambade’s summary of X-angle mtg Beam-beam interaction broadening of energy distribution (beamstrahlung) ~5% of power at 500 GeV backgrounds e+e- pairs radiative Bhabhas low energy tail of disrupted beam neutron “back-shine” from dump hadrons from gamma-gamma

9. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop9 « Time Structure: « Event rates: Luminosity: 3.4x10 34 cm -2 s -1 (6000xLEP) e + e -  qq,WW,tt,HX 0.1 / train e + e -    X:~200 /Train Background from Beamstrahlung: 6x10 10 /BX 140000 e + e - /BX + secondary particles (n,) 5 Bunch Trains/s t bunch =337ns But still: 600 hits/BX in Vtx detector 6 tracks/BX in TPC E=12GeV/BX in calorimeters E 20TeV/BX in forward cals.  Large B field and shielding High granularity of detectors and fast readout for stable pattern recognition and event reconstruction

10. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop10 IR Issues Hits/bunch train/mm2 in VXD, and photons/train in TPC pairs

11. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop11 Beam Energy need to know lumi-weighted Some analyses require better than 0.1%Some analyses require better than 0.1% techniques for determining the lumi-weighted : energy spectrometers Bhabha acolinearity Other possibilities :  Z, ZZ and WW events; use existing Z and W mass utilize Bhabha energies in addition to Bhabha acol  -pair events; use measured muon momentum 200 ppm feasible; 50 ppm a difficult challenge 200 ppm feasible; 50 ppm a difficult challenge Top-mass: need knowledge of E-spread FWHM to level of ~0.1%

12. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop12 Crossing Angle

13. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop13 Summary of MDI Issues Detector designers need input from MDI experts: –Minimum VTX radius (smaller than you’d like!) –Masking optimization and best model (MC tool) for backgrounds –Feasibility of crossing angle options Detector designers need MDI experts to appreciate: –Need for small on systematic lumi –Need for reduction in low-angle background –Need for diagnostic instrumentation This talk continues with a description of current designs –New tools are causing all to be rethought –I’ve completely neglected the special requirements of a detector optimized for  or e-  collisions Even worse low-angle background problems

14. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop14 There are currently 3 Detector Concepts The WorldWide Study is working on a plan: –organization of effort –benchmarking performance –cdr/tdr’s –selection 3 concepts are materializing: –The TESLA concept: TPC-tracker –Silicon tracker + calorimetry (SiD) –new large magnetic volume concept (Global Large Detector, GLD) Rethinking as new information available

15. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop15 Comparison of 3 Concepts (thanks to Y. Sugimoto) Very large R Jet chamber or TPC Scintilator/W-Pb-Fe Moderate R TPC tracker SiW ECAL Si tracking and ECAL Small R Smallest granularity

16. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop16 TESLA (and NA Large Det) (Thanks to Ties Behnke, Mike Ronan, Markus Schumacher)

17. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop17 Basic TESLA Detector Concept No hardware trigger, dead time free continous readout for complete bunch train (1ms) Zero suppression, hit recognition and digitisation in FE electronics Large gaseous central tracking device (TPC) High granularity calorimeters High precision microvertex detector All inside magnetic field of 4 Tesla

18. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop18 Overview of tracking system Central region: Pixel vertex detector (VTX) Silicon strip detector (SIT) Time projection chamber (TPC) Forward region: Silicon disks (FTD) Forward tracking chambers (FCH) (e.g. straw tubes, silicon strips) B=4T, R TPC =1.7m: momentum resolution  (1/p) < 7 x 10 -5 /GeV American version has larger TPC outer radius (2m), lower B (3T) looking at various TPC pad designs and readout

19. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop19 Vertex Detector: Conceptual Design 5 Layer Silicon pixel detector Small R1: 15 mm (1/2 SLD) Pixel Size:20x20m 2   Point =3 m Layer Thickness: <0.1%X 0 suppression of  conversions – ID of decay electrons minimize multiple scattering 800 million readout cells Hit density: 0.03 /mm 2 /BX at R=15mm  pixel sensors Read out at both ladder ends in layer 1: frequency 50 MHz, 2500 pixel rows  complete readout in: 50s ~ 150BX <1% occupancy no problem for track reconstruction expected Impact parameter d ~R1  point

20. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop20 Flavour Tagging LEP-c « Powerful flavour tagging techniques (from SLD and LEP)  M e.g. vertex mass ­ charm-ID: improvement by factor 3 w.r.t SLD Expected resolution in r,and r,z  ~ 4.2  4.0/p T (GeV) m

21. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop21 Gaseous or Silicon Central Tracking? gaseous silicon advantages of gaseous tracking: many points simple pattern recognition redundancy “but be careful with these comparisons!” This is something of an aesthetic argument

22. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop22 Forward Tracking FTD: 7 Disks 3 layers of Si-pixels 50x300m 2 4 layers of Si-strips  r = 90m FCH: 4 Layers Strawtubes or Silicon strips (double sided) 250 GeV 

23. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop23 Particle / Energy Flow 60 % charged particles:30 %  :10 %K L,n The energy in a jet is: Reconstruct 4-vectors of individual particles avoiding double counting Charged particles in tracking chambers Photons in the ECAL Neutral hadrons in the HCAL (and possibly ECAL)  need to separate energy deposits from different particles small X 0 and R Moliere : compact showers high lateral granularity D ~ O(R Moliere ) large inner radius L and strong magnetic field granularity more important than energy resolution  K L,n  e  Discrimination between EM and hadronic showers small X 0 / had longitudinal segmentation

24. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop24 Calorimeter Conceptual Design « ECAL and HCAL inside coil « large inner radius L= 170 cm  good effective granularity x~BL 2 /(R M D) 1/p x distance between charged and neutral particle at ECAL entrance ECAL: SiW, 40 layers/24Xo/0.9lhad, 1cm 2 lateral segmetation  E/E = 0.11/  E(GeV)  0.01 HCAL: many options scintilator tiles, analog or digital steel-scintillator sandwich

25. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop25 Forward Calorimeters LCAL: Beam diagnostics and fast luminosity (28 to 5 mrad) ~10 4 e + e — pairs/BX 20 TeV/BX 2MGy/yr Need radiation hard technology: SiW, Diamond/W Calorimeter or Scintillator Crystals LAT : Luminosity measurement from Bhabhas (83 to 27 mrad) SiW Sampling Calorimeter aim for  L / L ~ 10 -4 require  = 1.4 rad TDR version of maskL* = 3 m Tasks: Shielding against background Hermeticity / veto

26. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop26 SiD Design Starting Point (Thanks to Marty Breidenbach, John Jaros) B = 5T R ecal = 1.25m Z ecal = 1.74m

27. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop27 The SiD Rationale Premises: particle flow calorimetry will deliver the best possible performance Si/W is the right technology for the ECAL Excellent physics performance, constrained costs Si/W calorimetry for excellent jet resolution therefore… Limit Si/W calorimeter radius and length, to constrain cost Boost the B field to recover BR 2 for particle flow, improve momentum resolution for tracker, reduce backgrounds for VXD Use Si microstrips for precise tracking

28. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop28 Cost (and physics) balance R and B High Field Solenoid and Si/W Ecal are major cost drivers. Magnet Costs  Stored Energy  (SiD ~1.1GJ  80-100 M$) Cost [M$] Fix BR 2 =7.8, tradeoff B and R  Stored Energy [GJ] Delta M$ vs B, BR 2 =7.8 [Tm 2 ]

29. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop29 ECAL

30. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop30 Si Detector/ Readout Chip Readout ~1k pixels/detector with bump-bonded ASIC Power cycling – only passive cooling required Dynamic range OK (0.1 - 2500 mip) Pulse Height and Bunch Label buffered 4 deep to accommodate pulse train

31. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop31 HCAL Inside the coil R in = 1.42m; R out = 2.44m 4 Fe (or W, more compact) 2cm Fe, 1cm gap Highly segmented 1x1 cm 2 – 3x3 cm 2 ~ 40 samples in depth Technology? RPC Scint Tile GEM S. Magill (ANL) …many critical questions for the SiD Design Study: thickness? Segmentation? Material? Technology?

32. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop32 Silicon Tracking Why silicon microstrips? SiD starting point Robust against beam halo Thin, even for forward tracks. Won’t degrade ECAL Stable alignment and calibration. Excellent momentum resolution  p/p 2 ~2 x 10 -5

33. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop33 VXD Tesla SiD Shorten barrel, add endcaps.  Shorten Barrel CCDs to 12.5 cm (vs. 25.0cm) supporting disk endcaps (multiple CCDs per disk)  add 300  m Si self-supporting disk endcaps (multiple CCDs per disk) This extends 5 layer tracking over max , improves forward pattern recognition.  improve  Coverage, improve  impact param 5 CCD layers.97 (vs..90 TDR VXD) 4 CCD layers.98 (vs..93 TDR VXD) Readout speed and EMI are big questions.

34. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop34 SiD Subsystems So far, we’ve concentrated on calorimetry, tracking, and magnet, since they define SiD architecture. Other subsystems need development & integration. Flux Return/Muons/Had Tail Catcher B field homogeneity for forward ecal? Longitudinal segmentation? Technology? Very Forward Tracking Pixels or strips? Very Forward Cal (huge and active area!) Active masks and vetoes Lumcal Beamcal (pair monitor)

35. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop35 G lobal L arge D etector (Thanks to Y. Sugimoto)

36. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop36 Basic design concept  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  p t /p t 2 –Re-consider the optimum sub-detector technologies based on the recent progresses Different approaches – B R in 2 : SiD – B R in 2 : TESLA – B R in 2 : Large/Huge Detector

37. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop37 Optimization for PFA Jet energy resolution –  jet 2 =  ch 2 +   2 +  nh 2 +  confusion 2 +  threashold 2 –Perfect particle separation: Charged-  /nh separation –Confusion of  /nh shower with charged particles is the source of  confusion  Separation between charged particle and  /nh shower is important –Charged particles should be spread out by B field –Lateral size of EM shower of  should be as small as possible ( ~ R m effective : effective Moliere length) –Tracking capability for shower particles in HCAL is a very attractive option  Digital HCAL

38. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop38 Merits and demerits of Large/Huge detector Merits –Advantage for PFA –Better p t and dE/dx resolution for the main tracker –Higher efficiency for long lived neutral particles (Ks, , 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 R min of VTX because of beam background  (IP)~5  10/(p  sin 3/2  )  m is still achievable using wafers of ~50  m thick

39. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop39 Forward Detector components Si forward disks / Forward Calorimeter –Tracking down to cos  =0.99 –Luminosity measurement 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 Si pair monitor –Measure beam profile from r-phi distribution of pair- background –Radiation-hard Si detector (Si 3D-pixel)

40. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop40 Parameters compared SiDTESLAGLD SolenoidB(T)543 Rin(m)2.483.03.75 L(m)5.89.2 9.86 E stored (GJ)1.42.3 1.8 Main Tracker R min (m)0.20.36 0.4 R max (m)1.251.62 2.0 BL 2.5 5.77.1 9.7  m  7150 N sample 5200 220  pt/pt 2 3.6e-51.5e-4 1.2 e-4

41. 6 Jan 2005Mark Oreglia, SLAC MDI Workshop41 Paramters (cont’d) SiDTESLAGLD ECALR in (m) 1.271.68 2.1 BR in 2 8.111.3 13.2 TypeW/Si ( W/Sci ) R m eff (mm) 1824.4 16.2 BR in 2 /R m eff 448462 817 Z (m)1.722.83 2.8 BZ 2 /R m eff 8221311 1452 X0X0 2124 27 E+H CAL 5.55.2 6.0 t (m)1.181.3 1.4