Large/Huge Detector Concept

9. Nov. 2004

@7th ACFA LCWS in Taipei

Y. Sugimoto

KEK

Background

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 pt

min 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

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

Design Concept

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 pt/pt

2 Re-consider the optimum sub-detector technologies based on th

e recent progresses

EEE

pp

pIP

tt

/3.0/

105/

sin/105)(52

2/3

Optimization for PFA

Jet energy resolution jet

2 = ch2 +

2 + nh2 + confusion

2 + threashold2 　

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 po

ssible ( ~ Rmeffective: effective Moliere length)

Tracking capability for shower particles in HCAL is a very attractive option Digital HCAL

EEjet /%15~/

Optimization for PFA

Figure of merit (ECAL): Barrel: B Rin

2/ 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 cer

tain distance from a charged track scales as ~Rin2)

Different approaches B Rin

2 : SiD B Rin

2 : TESLA

B Rin2 : Large/Huge Detector

Effective Moliere Length

Absorber W : Rm ~ 9mm Pb : Rm ~ 16mm

Gap : Sensor + R.O. elec + etc.

xa xg

Effective Moliere Length = Rm (1+xg/xa)

Central Tracker

Figure of merit:

samplings ofNumber :

length Tracking :

field Magnetic :

resolution Spatial :

4

7203.3 )(22

n

L

B

nBLtptp

n is proportional to L if sampling pitch is constant

5.22

1

BLp

p

t

t

A possible modification from GLC detector model

Larger Rmax (2.0m) of the tracker and Rin (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 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 (2.05m2.8m) 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)

Comparison of parametersSiD TESLA JLC GLC GLD [1] LD

Solenoid B(T) 5 4 2 3 3 3

Rin(m) 2.48 3.0 4.25 3.75 3.75 3.7

L(m) 5.8 9.2 9.1 6.8 9.86 9.4

Est(GJ) 1.4 2.3 1.1 1.8 1.7

Main Tracker

Rmin (m) 0.2 0.36 0.45 0.45 0.4 0.5

Rmax(m) 1.25 1.62 2.3 1.55 2.0 2.0

BL2.5 5.7 7.1 9.3 3.8 9.7 8.3

m 7 150 100 85 150 150

Nsample 5 200 100 50 220 144

pt/pt2 3.6e-5 1.5e-4 1.3e-4 2.9e-4 1.2 e-4

1.6e-4

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

Comparison of parametersSiD TESLA JLC GLC GLD LD

ECAL Rin (m) 1.27 1.68 2.5 1.6 2.1 2.0

BRin2 8.1 11.3 12.5 7.7 13.2 12.0

Type W/Si W/Si Pb/Sci Pb/Sci (W/Sci) Pb/Sci

Rmeff (mm) 18 24.4 21.3 25.5 16.2 21.3

BRin2/Rm

eff 448 462 588 301 817 565

Z (m) 1.72 2.83 2.9 2.05 2.8 3.0

BZ2/Rmeff 822 1311 792 494 1452 1271

X0 21 24 29 27 27 29

E+H

CAL

5.5 5.2 6.9 7.3 6.0 6.9

t (m) 1.18 1.3 1.5 1.8 1.4 1.7

Detector size

Area of EM CAL

(Barrel + Endcap) SiD: ~40 m2 / layer TESLA: ~80 m2 / layer GLD: ~ 100 m2 / layer (JLC: ~130 m2 / layer)

• EM Calorimeter

Global geometry(All parameters are tentative)

Global geometry

Global geometry

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

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, , and un

known 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

(IP)~5 10/(psin3/2) m is still achievable using wafers of ~50

m thick

Detector Components

Detector components

EM Calorimeter Small Rm

eff W radiator Make gaps as small as possible

Small segmentation : seg < 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

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

mmdzBz

Brz2max

0

(TESLA TDR)

Detector components

Muon system No serious study for GLD so far Design of muon system is indispensable for the solenoid/iron-yok

e design, which takes large fraction of the total cost Si inner/outer(?) tracker

Time stamping capability (separation of bunches)

High resolution Si strip det.

improves momentum resolution Si endcap tracker

Improves momentum resolution

in the end-cap region where main tracker coverage is limited

pt/pt2

TPC only 1.2e-4

TPC+VTX 4.5e-5

TPC+VTX+SIT 2.9e-5

SIT: =7m, 3 layersVTX: =3m, 5 layers

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)

Detector components 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 at low momentum due to large Rmin

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 1st layer of ECAL or additional detector ? What is the physics case?

Detector components

TOF (Cont.)

K-

Sep

ara

tion

()

Momentum (GeV/c)

Assumptions:TOF)=100psL=2.1mdE/dx)=4.5%

Status of the study

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 Pyt

hia6.2, 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

( )cutall events

all events

E d d

FE

dcut

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 trackin

g region is OK

Geometry of muon detector is tentative. More realistic input is necessary

1 .241187 .72356 1.688 2.171 3.135 3.618 4.583 5.547 6.03 6.994 7.477 8.442 8.924 9.889 10.853 11.336 12.301 12.783 13.748 14.712 15.195 16.16 16.642 17.607 18.089 19.054 20.019 20.501 21.466 21.948 22.913 23.877

1111111111

mmmmdzBz

Brz28.1max

0

Other studies

See presentations in parallel sessions and http://ilcphys.kek.jp/

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

Backup slides

Beam Calorimeter is placed in the high background region

Same sign

Opposite sign

by T.AsoGLC Parameter, B=4T

Pair background track density