GLC Detector Geometry Y. Sugimoto

Introduction Figure of merit : Main Tracker

Figure of merit : Calorimeter   jet 2 =  ch 2 +   2 +  nh 2 +  confusion 2 +  threashold 2  Separation of charged particles and  /nh is important (See J.C. Brient’s talk at LCWS2004)  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) Barrel: B R in 2 / R m effective Endcap: B Z 2 / R m effective R in : Inner radius of Barrel ECAL Z : Z position 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 )

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

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

B=0

Comparison of Detector Models SDTESLAGLCLDJLC SolenoidB(T) Rin(m) L(m) E st (GJ) TrackerR min (m) R max (m)  m  N sample  pt/pt 2 3.9e-51.5e-42.9e-41.6e-41.3e-4

Comparison of Detector Models SDTESLAGLCLDJLC ECALR in (m) p t min BR in TypeW/Si Pb/Sci R m (mm) BR in 2 /R m Z BZ 2 /R m X0X Total t (m)

Possible modification of GLC Detector Larger R max of the tracker and R in of ECAL Keep solenoid radius same:  Somewhat thinner CAL (but still 6 ), but does it matter? Use W/Sci(/Si) instead of Pb/Sci for ECAL  Effective Rm: 25.5mm  16.2mm (2.5mm W / 2.0mm Gap)  Much smaller segmentation by Si pad layers Put ECCAL at larger Z  Longer Solenoid  Preferable for B-field uniformity if TPC is used If l*=4.3 (3.5) m is adopted,  10 cm thick W shield around the support tube is not necessary  R min of the tracker can be reduced  It is preferable Z pole-tip < l* both for neutron b.g. and QC support

GLC B-field non-uniformity mm Z (m) TESLA TDR Limit R=0.1m R=2.0m TESLA TDR Limit: by H.Yamaoka

Comparison of Detector Models SDTESLAGLDLDJLC SolenoidB(T) Rin(m) L(m) E st (GJ) TrackerR min (m) R max (m)  m  N sample  pt/pt 2 3.9e-51.5e-41.1e-41.6e-41.3e-4

Comparison of Detector Models SDTESLAGLDLDJLC ECALR in (m) p t min (GeV/c) BR in TypeW/Si W/Sci/SiPb/Sci R m (mm) BR in 2 /R m Z BZ 2 /R m X0X Total t (m)

EM Calorimeters Area of EM CAL (Barrel + Endcap)  SD: ~40 m 2 / layer  TESLA: ~80 m 2 / layer  GLD: ~ 100 m 2 / layer  (JLC: ~130 m 2 / layer)

Global Geometry

Interaction Region

Summary The LC detector optimized for “Energy Flow Algorithm” is realized with a “Truly large detector” “Truly large detector” can be achieved with a minimal modification of GLC detector, and it can get better performance than any other detector models. Compared with the present GLC detector,  Rmin and Zmin of EM CAL should be increased  Effective Moliere length of ECAL should be decreased  Magnetic field and radius of the solenoid unchanged, but somewhat longer For TESLA detector, it is hard to make Rmin of ECAL larger because of the cost of the Si/W EMCAL The key is Calorimeter

Summary (Cont.) Things to do:  Design new (longer) solenoid magnet with better uniformity  TPC: Determine the requirement for the B-field uniformity  CAL: Simulations Show the advantage of Large detector 4 cm 2 granularity is good enough for EFA? If not, how many Si layers are necessary? Consider tungsten (W) instead of lead (Pb) Or still stick to hardware compensation rather than EFA? How many ’s needed?  Collaboration with US LD: GLC+LD = GLD