Introduction to Large/Huge Detector study 10. Nov. meeting in 7 th ACFA LCWS in Taipei Y. Sugimoto KEK

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.

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)

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/ ,  ) Minimum veto angle Anything else?

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

Detector R&D 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(?)

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

Backup slides

Detector components EM Calorimeter Small R m eff  W radiator Make gaps as small as possible Small segmentation :  seg < R m eff 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

Detector components Main tracker TPC is a natural solution for the Large tracker Positive ion feedback (2-  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)

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  pt/pt 2 TPC only1.2e-4 TPC+VTX4.5e-5 TPC+VTX+SIT2.9e-5 SIT:  =7  m, 3 layers VTX:  =3  m, 5 layers

Detector components Si forward disks / Forward Calorimeter Tracking down to cos  =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?

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

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 p t min same as before)  Degraded p t res 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

Large/Huge detector study so far Actually, discussion on Large/Huge detector study has started before the ITRP decision Started discussion after 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

A possible modification from GLC detector model Larger R max (1.55  2.0m) of the tracker and R in (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 6 ), but does it matter? Use W instead of Pb for ECAL absorber Effective R m : 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 Z pole-tip < l* (4.3m?) both for neutron b.g. and QC support ( l* :distance between IP and QC1)

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

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  p t /p t 2 Re-consider the optimum sub-detector technologies based on the recent progresses

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

Optimization for PFA Figure of merit (ECAL): Barrel: B R in 2 / R m effective Endcap: B Z 2 / R m effective R in : 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 ~R in 2 ) Different approaches B R in 2 : SiD B R in 2 : TESLA B R in 2 : Large/Huge Detector

Effective Moliere Length Absorber W : Rm ~ 9mm Pb : Rm ~ 16mm Gap : Sensor + R.O. elec + etc. xaxa xgxg Effective Moliere Length = R m (1+x g /x a )

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

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

Comparison of parameters SiDTESLAJLCGLCGLD [1] LD SolenoidB(T) Rin(m) L(m) E st (GJ) Main Tracker R min (m) R max (m) BL  m  N sample  pt/pt 2 3.6e-51.5e-41.3e-42.9e e-4 1.6e-4 [1] GLD is a tentative name of the Large/Huge detector model. All parameters are tentative.

Comparison of parameters SiDTESLAJLCGLCGLDLD ECALR in (m) BR in TypeW/Si Pb/Sci (W/Sc i) Pb/Sci R m eff (mm) BR in 2 /R m eff Z (m) BZ 2 /R m eff X0X E+H CAL t (m)

Detector size Area of EM CAL (Barrel + Endcap) SiD: ~40 m 2 / layer TESLA: ~80 m 2 / layer GLD: ~ 100 m 2 / layer (JLC: ~130 m 2 / layer) EM Calorimeter

Global geometry (All parameters are tentative)

Global geometry

GLD is smaller than CMS “Large” is smaller than “Compact”

Detector components TOF (Cont.) K-  Separation (  ) Momentum (GeV/c) Assumptions:  TOF)=100ps L=2.1m  dE/dx)=4.5%

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

Charged –  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 d cut F

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

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

Other studies See presentations in parallel sessions and

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 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 Place: Room 204

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