Äîêóìåíò âçÿò èç êýøà ïîèñêîâîé ìàøèíû. Àäðåñ îðèãèíàëüíîãî äîêóìåíòà : http://zebu.uoregon.edu/~uochep/talks/talks02/Brau05-02.pdf Äàòà èçìåíåíèÿ: Wed Aug 7 22:46:49 2002 Äàòà èíäåêñèðîâàíèÿ: Tue Oct 2 11:07:28 2012 Êîäèðîâêà: Ïîèñêîâûå ñëîâà: hep-ex

Linear Collider Detectors
Jim Brau Univ. of Oregon SLAC Linear Collider R&D Opportunities Workshop May 31, 2002

· Many open issues for LC detectors · Physics goals involve low event rates with relatively low backgrounds
­ opportunity for very efficient and precise approaches

LC Detectors, Jim Brau, SLAC, May 31, 2002

1


The "next" Linear Collider
The "next" Linear Collider proposals include plans to deliver a few hundred fb-1 of integrated lum. per year
TESLA
(1034) (GeV) (GHz) (ns) 3.4 ® 5.8 500 ® 800 23.4 ® 35 1.3 337 ® 176 2820 ® 4886 3.2 ® 4.4

JLC-C
0.43 500 34 5.7 2.8 72

NLC/JLC-X *
2.2 ® 3.4 500 ® 1000 70 11.4 1.4 190 4.6 ® 8.8

design

E

CM

Eff. Gradient (MV/m) RF freq.

Dt

bunch

#bunch/train Beamstrahlung (%)

* US and Japanese X-band R&D cooperation, but machine parameters may differ

LC Detectors, Jim Brau, SLAC, May 31, 2002

2


Physics Requirements
· The Linear Collider physics program includes a broad range of goals from discovery to high precision, ranging from ECM ~ MZ to ~ 1 TeV
­ ­ ­ ­ ­ Higgs studies Supersymmetry Strong WW scattering Top physics Precision Z0

LC Detectors, Jim Brau, SLAC, May 31, 2002

3


Detector Requirements
There is perception that Linear Collider Detectors are trivial Not true! The detector R&D devoted to the challenges of the LHC are helpful but not sufficient The LC requirements differ from hadron collider requirements hadron collider: large cross sections and large backgrounds linear collider: smaller event rates and smaller (though not negligible) backgrounds The LC requires a different optimization
LC Detectors, Jim Brau, SLAC, May 31, 2002

4


Detector Comparisons
Tracker thickness: CMS ATLAS LC 0.30 X 0.28 X 0.05 X
0 0 0

Vertex Detector layer thickness: CMS 1.7 % X0 ATLAS 1.7 % X0 LC 0.06% X0 Vertex Detector granularity: CMS 39 Mpixels ATLAS 100 Mpixels LC (Telsa) 800 Mpixels ECAL granularity (detector elements): CMS 76 x 103 ATLAS 120 x 103 LC(Tesla) 32 x 106
LC Detectors, Jim Brau, SLAC, May 31, 2002

5


Detector Requirements
Unburdened by high radiation and high event rate, the LC can use ú vxd 3-6 times closer to IP 35 times smaller pixels and 30 times thinner vxd layers 6 times less material in tracker 10 times better track momentum resolution > 200 times higher ECAL granularity (if it's affordable) But to capitalize on this opportunity, we must begin the R&D now

LC Detectors, Jim Brau, SLAC, May 31, 2002

6


Prominent R&D Goals
Develop advanced CCD vertex detector Simulate and prototype superb energy flow calorimeter Understand limitations of tracking options and develop them Develop beamline instrumentation (E, pol, lum spectrum, ...) Refine and certify background estimates Develop high-field solenoid Develop cost reduction strategies eg. integrated cal readout digital cal We don't have these capabilities now
LC Detectors, Jim Brau, SLAC, May 31, 2002

7


Beamline Issues
·Bunch structure ·IR layout and masks ·Small spot size issues ·Beam-beam interactions

LC Detectors, Jim Brau, SLAC, May 31, 2002

8


IR Issues
Time structure

NLC (JLC)

Tesla

LC Detectors, Jim Brau, SLAC, May 31, 2002

9


IR Issues
NLC (JLC) 190 bunches/train ÷ 1.4 ns bunch spacing ÷ 0.27 msec long train might want to time-stamp within train? ÷ crossing angle (20 mrad) - (8 mrad for JLC) Tesla 2820 bunches/train ÷ 950 msec long much higher duty cycle (how to handle?) no crossing angle, but could have one

LC Detectors, Jim Brau, SLAC, May 31, 2002

10


IR Issues
Solenoid effects transverse component of solenoid must be compensated - straight forward NLC - L Detector IR Layout L* = 3.8 m Masks M1 - W/Si M2 - W Low-Z
LC Detectors, Jim Brau, SLAC, May 31, 2002

11


IR Issues
Small spot size issues nm vertical stability required
÷ permanent magnets for QD0 and QF1

passive compliance + active suppression

15 ns response within bunch train (NLC)

Beam-beam interaction broadening of energy distribution (beamstrahlung) ~5% of power at 500 GeV backgrounds
e+e- pairs radiative Bhabhas low energ tail of disrupted beam neutron "back-shine" from dump hadrons from gamma-gamma

LC Detectors, Jim Brau, SLAC, May 31, 2002

12


IR Issues
3 Tesla
VXD limit

100,000

50,000

e+e- pairs

Hits/bunch train/mm2 in VXD, and photons/train in TPC
LC Detectors, Jim Brau, SLAC, May 31, 2002

13


IR Issues

Synchrotron radiation photons from beam halo in the final doublet halo limited by collimation system
LC Detectors, Jim Brau, SLAC, May 31, 2002

14


IR Issues
The experimenters (us) must pay attention to these issues, work with the accelerator physicists to minimize them, and prepare to live with what's left

LC Detectors, Jim Brau, SLAC, May 31, 2002

15


Detector Requirements
Vertex Detector physics motivates excellent efficiency and purity large pair background from beamstrahlung ® large solenoidal field (¨ 3 Tesla) pixelated detector [(20 mm)2 ® 2500 pixels/mm2] min. inner radius (< 1.5 cm), ~5 barrels, < 4 mm resol, thickness < 0.2 % X0 Calorimetry excellent jet reconstruction eg. W/Z separation use energy flow for best resolution (calorimetry and tracking work together) fine granularity and minimal Moliere radius charge/neutral separation ® large BR2
LC Detectors, Jim Brau, SLAC, May 31, 2002

16


Detector Requirements
Tracking robust in Linear Collider environment isolated particles (e charge, m momentum) charged particle component of jets jet energy flow measurements assists vertex detector with heavy quark tagging forward tracking (susy and lum measurement) Muon system high efficiency with small backgrounds secondary role in calorimetry ("tail catcher") Particle ID dedicated system not needed for primary HE physics goals particle ID built into other subsystems (eg. dE/dx in TPC)
LC Detectors, Jim Brau, SLAC, May 31, 2002

17


Beamline requirements
Beam energy measurement Need 50-100 MeV (10-4)precision SLD WISRD technique is probably adequate (needs work) TESLA plans BPM measurement pre-IP (needs work) Luminosity spectrum acolinearity of Bhabhas question - can it be extracted from WISRD? What about effect of beam disruption Polarization measurement SLD achieved 0.5% - same technique at NLC should give 0.25% TESLA plans only before IP (is this okay? NLC bias says no) Positron polarization helps dramatically
LC Detectors, Jim Brau, SLAC, May 31, 2002

18


LC Detectors
several strawman detectors are under study

LC Detectors, Jim Brau, SLAC, May 31, 2002

19


LC Detectors
Tesla TDR Detector American ( 2 High Energy and 1 Low Energy) - Snowmass LC Resource Book 1.) L conventional large detector based on the early American L (Sitges/Fermilab LCWS studies) 2.) SD (silicon detector) motivated by energy flow measurement 3.) P (low budget, trimmed-down version) JLC Detector 3 Tesla detector
References: Particle Physics Experiments at JLC, hep-ph/.0109166; and http://acfahep.kek.jp TESLA TDR, DESY 2001-011, hep-ph/0106315 Linear Collider Resource Book for Snowmass 2001, hep-ex/0106055-58
LC Detectors, Jim Brau, SLAC, May 31, 2002

20


LC Detectors
TESLA TDR · "pixel" vertex detector · silicon/W EM calorimeter (energy-flow) · 4 T coil
TESLA TDR, DESY 2001-011, hep-ph/0106315

LC Detectors, Jim Brau, SLAC, May 31, 2002

21


LC Detectors
· TESLA TDR

LC Detectors, Jim Brau, SLAC, May 31, 2002

22


Resource Book L Detector
5 barrel CCD vertex detector 3 Tesla Solenoid outside hadron calorimeter TPC Central Tracking (52 ® 190 cm) Intermediate Si strips at R=48 cm Forward Si discs (5 each) Pb/scintillator EM and Had calorimeter EM 40 x 40 mrad2 Had 80 x 80 mrad2 Muon - 24 5 cm iron plates with gas chambers (RPC?)

Solenoid

Linear Collider Resource Book for Snowmass 2001, hep-ex/0106055-58

LC Detectors, Jim Brau, SLAC, May 31, 2002

23


Resource Book L Detector

Solenoid

LC Detectors, Jim Brau, SLAC, May 31, 2002

24


Resource Book SD Detector
5 barrel CCD vertex detector 5 Tesla Solenoid outside hadron calorimeter Silicon strips or drift (20 ® 125 cm) 5 layers Forward Si discs (5 each) W/silicon EM calorimeter 0.5 cm pads with 0.7 X0 sampling and Cu or Fe Had calorimeter (4 l) 80 x 80 mrad2 Muon - 24 5cm iron plates with gas chambers (RPC?)
Solenoid

LC Detectors, Jim Brau, SLAC, May 31, 2002

25


Resource Book SD Detector

Solenoid

LC Detectors, Jim Brau, SLAC, May 31, 2002

26


Resource Book High Energy Detector Comparison

L Solenoid R(solenoid) 3T 4.1 m

SD 5T 2.8 m

12 m2T 8 m2 T BR2 (tracking) -------------------------------------------------------------------RM (EM cal) 2.1 cm 1.9 cm 3.8 0.26 trans.seg RM 0.6 (6th layer Si) -------------------------------------------------------------------Rmax(muons) 645 cm 604 cm
LC Detectors, Jim Brau, SLAC, May 31, 2002

27


Resource Book P Detector
Designed for a low budget, reduced performance 5 barrel CCD vertex detector 3 Tesla Solenoid inside hadron calorimeter TPC Central Tracking (25 ® 150 cm) Pb/scintillator or Liq. Argon EM and Hadronic calorimeter EM 30 x 30 mrad2 Had 80 x 80 mrad2 Muon - 10 10cm iron plates w/ gas chambers (RPC?)

LC Detectors, Jim Brau, SLAC, May 31, 2002

28


Subsystems
·Vertex Detector ·Tracker ·Calorimeter ·Muon Detector ·Beamline measurements
LC Detectors, Jim Brau, SLAC, May 31, 2002

29


Vertex Detector
American L, SD, and P detectors assume the same CCD VXD ~700,000,000 pixels [20x20x20 (mm)3] 3 mm hit resolution inner radius = 1.2 cm 5 layer stand-alone tracking

Cos q = 0.98

LC Detectors, Jim Brau, SLAC, May 31, 2002

30


Impact Parameter Resolution

d R ( c m)

B. Schumm
LC Detectors, Jim Brau, SLAC, May 31, 2002

31


Flavor Tagging

bottom

charm

T. Abe
LC Detectors, Jim Brau, SLAC, May 31, 2002

32


The R&D Program

Vertex Detector
The R&D program must include the following resolve discrepancy in Higgs BR studies understand degradation of flavor tagging with real physics events compared to monojets (as seen in past studies) understand requirements for inner radius, and other parameters what impact on physics what impact on collider if minimize inner radius? segmentation requirements (two track resolution) 500 GeV u,d,s jets pixel size develop hardened CCDs develop CCD readout, with increased bandwidth develop very thin CCD layers (eg. stretched) investigate alternatives to CCDs

LC Detectors, Jim Brau, SLAC, May 31, 2002

33


Tracking
L Inner Radius 50 cm Outer Radius 200 cm Layers Fwd Disks B(Tesla) 144
TPC

SD 20 cm 125 cm 5
Si drift or mstrips

P 25 cm 150 cm 122
TPC

double-sided Si double-sided Si double-sided Si

5

5

5

3

5

3

LC Detectors, Jim Brau, SLAC, May 31, 2002

34


Tracking Resolution

B. Schumm
LC Detectors, Jim Brau, SLAC, May 31, 2002

35


refine the understanding of backgrounds tolerance of trackers to backgrounds The R&D will large background be a problem for the TPC (field distortions, etc) Program are ionic space charge effects understood? study pattern recognition for silicon tracker (include vxd) (2D vs. 3D) study alignment and stability of silicon tracker what momentum resolution is required for physics, eg. Higgs recoil, slepton mass endpoint, low and high energy understand tracker material budget on physics physics motivation for dE/dx (what is it?) detailed simulation of track reconstruction, especially for a silicon option, complete with backgrounds and realistic inefficiencies The R&D program include CCDs (presumably) in track reconstruction must include this timing resolution readout differences between Tesla/NLC time structure list role of intermediate layer tracking errors in energy flow (study with calorimeter) forward tracking role with TPC alignment (esp. with regard to luminosity spectrum measurement) develop thorough understanding of trade-offs in TPC, silicon options large volume drift chamber (being developed at KEK) development of large volume TPC (large European/US collaboration at work) development of silicon microstrip and silicon drift systems (being developed in US & Japan) study optimal geometry of barrel and forward system two track resolution requirements (esp. at high energy) this impacts calorimetry - how much? study K0 and L efficiencies (impacts calorimetry?)

Tracking

LC Detectors, Jim Brau, SLAC, May 31, 2002

36


Calorimeters
EM Tech Had Tech Inner Radius EM-outer Radius HAD-outer Radius Solenoid Coil EM trans. seg. Had trans. seg. L Pb/scin (4mm/1mm)x40 Pb/scin 196 cm 220 cm 365 cm outside Had 40 mr 80 mr SD W/Si (2.5mm/gap)x40 Cu or Fe/RPC (or Pb) 127 cm 142 cm 245 cm outside Had 4 mr 80 mr P Pb/scin (4mm/3mm)x32 Pb/scin 150 cm 185 cm 295 cm between EM/Had 30 mr 80 mr
37

LC Detectors, Jim Brau, SLAC, May 31, 2002


Calorimeters

LC Detectors, Jim Brau, SLAC, May 31, 2002

38


Calorimeter Resolution
Jet energy resolution
L: 0.18/æEjet SD: 0.15/æEjet

Di-jet mass resolution
L: 0.64/æEZ SD: 0.72/æEZ

e+e- ® 2 jets

e+e- ® ZZ

These are idealized studies, and resolutions will be worse. R. Frey
EM resolution: L: SD: s s
EM EM

/ E = (17% / æE) å / E = (18% / æE) å

LC Detectors, Jim Brau, SLAC, May 31, 2002

39


The R&D Program

Calorimetry

The R&D program must address these issues

energy flow need detailed simulation followed by prototype beam test demonstration further develop physics cases for excellent energy flow eg. Higgs self-coupling, WW/ZZ at high energy, recon of top and W for anomalous couplings?, others (SUSY, BR(H>160)) integrate E-flow with flavor tagging study readout differences for Tesla/NLC importance of K0/Lambda in energy flow calorimeter parametrize E-flow for fast simulation forward tagger requirements study effect of muons from collimators/beamline further development of simulation clustering tracking in calorimeter digital calorimeter study parameter trade-offs (R seg, layers, coil location, transverse seg.) in terms of general performance parameters in terms of physics outcome refine fast-sim parameters from detailed simluation integrate electronics with silicon detectors in Si/W reduce silicon detector costs engineer reduced gaps mechanical/assembly issues B = 5 Tesla? can scintillating tile Ecal compete with Si/W in granularity, etc.? crystal EM (value/advantages/disadvantages) barrel/endcap transition (impact and fixes)
LC Detectors, Jim Brau, SLAC, May 31, 2002

40


Muon Detection
Model L 24 ´ 5 cm Fe plates + RPCs srq » 1 cm (x 24) sz » 1 cm (x 4) coverage to ~ 50 mrad Model SD 24 ´ 5 cm Fe plates + RPCs srq » 1 cm (x 24) sz » 1 cm (x 4) coverage to ~ 50 mrad Model P 10 ´ 10 cm Fe plates + RPCs srq » 1 cm (x 10) sz » 1 cm (x 2) coverage to ~ 50 mrad
LC Detectors, Jim Brau, SLAC, May 31, 2002

41


The R&D Program

The R&D program must include the following requirements for purity/efficiency vs. momentum on physics channels understand role in energy flow (work with calorimetry) detailed simulation prototype beam tests mechanical design of muon system development of detector options, including scintillator and RPCs

Muons

LC Detectors, Jim Brau, SLAC, May 31, 2002

42


The R&D Program

The R&D program must include the following: luminosity spectrum measurement beam energy measurement polarization measurement positron polarization systematics of the Blondel scheme veto gamma-gamma very forward system

Beamline, etc.

General

is calibration running at Z0 peak essential/useful/useless? design a 4-5 Tesla coil

Comment

In general it would be good if more work was done exercising the simulation code that has been put together under the leadership of Norman Graf. Much work has been devoted toward developing a detailed full simulation.
LC Detectors, Jim Brau, SLAC, May 31, 2002

43


American Linear Collider Physics Group Working Groups
Detector and Physics Simulations: Norman Graf/Mike Peskin Vertex Detector: Jim Brau /Natalie Roe Tracking: Bruce Schumm/Dean Karlen/Keith Riles Particle I.D.: Bob Wilson Calorimetry: R. Frey/A. Turcot/D. Chakraborty Muon Detector: Gene Fisk DAcq, Magnet, and Infrastructure: Interaction Regions, Backgrounds: Tom Markiewicz/Stan Hertzbach Beamline Instrumentation: M. Woods /E. Torrence/D. Cinabro Higgs: R. Van Kooten/M. Carena/H. Haber SUSY: U. Nauenberg/J. Feng /F. Paige New Physics at the TeV Scale and Beyond: J. Hewett/D. Strom/S. Tkaczyk Radiative Corrections (Loopverein): U. Baur/S. Dawson/D. Wackeroth Top Physics, QCD, and Two Photon: Lynn Orr/Dave Gerdes Precision Electroweak: Graham Wilson/Bill Marciano gamma-gamma, e-gamma Options: Jeff Gronberg/Mayda Velasco e-e-: Clem Heusch

LHC/LC Study Group
LC Detectors, Jim Brau, SLAC, May 31, 2002

44


NLC Cost Estimates
In preparation for Snowmass 2001, the working groups developed an estimate of the expected detector costs General considerations: Based on past experience Contingency = ~ 40% Designs constrained High Energy IR L 359.0 M$ SD 326.2 M$ Low Energy IR P 210.0 M$
LC Detectors, Jim Brau, SLAC, May 31, 2002

45


NLC Cost Estimates
1.1 Vertex 1.2 Tracking 1.3 Calorimeter 1.3.1 EM 1.3.2 Had 1.3.3 Lum 1.4 Muon 1.5 DAQ 1.6 Magnet & supp 1.7 Installation 1.8 Management 1.9 Contingency Total
SUBTOTAL

L 4.0 34.6 48.9 (28.9) (19.6) (0.4) 16.0 27.4 110.8 7.3 7.4
256.4

SD 4.0 19.7 60.2 (50.9) (8.9) (0.4) 16.0 52.2 75.6 7.4 7.7
242.8

P 4.0 23.4 40.7 (23.8) (16.5) (0.4) 8.8 28.4 30.5 6.8 7.4
150.0

102.6 83.4

60.0

359.0 326.2 210.0
LC Detectors, Jim Brau, SLAC, May 31, 2002

46


The R&D Program
· There is much work to do - let's get going · We have identified many of the issues
­ no doubt, this list is incomplete, but strategies are beginning to be formulated to address them, · within the ALCPG working groups and the "consortia"

· The report from the International R&D committee reviews the R&D activities
· http://blueox.uoregon.edu/~jimbrau/LC/LCrandd.ps

­ Please review this draft report (it is a first attempt) ­ send comments to the committee by June 15 ­ the report will then be updated

LC Detectors, Jim Brau, SLAC, May 31, 2002

47


Coming Meetings
· North American
­ June 27-29, UC-Santa Cruz

· Other regions
­ July 10-12, Tokyo, Japan (5th ACFA Workshop)
­ (ECFA/DESY met April 12-15 in St. Malo, France)

· Inter-regional
­ August 26-30, Jeju Is., Korea (LCWS 2002)

LC Detectors, Jim Brau, SLAC, May 31, 2002

48


Santa Cruz Goals
· The parallel session on the 28th will include
­ 1.) organize an evaluation of key issues relating to the choice of detector and accelerator technology ­ 2.) coordinate the on-going and proposed R&D efforts; all planned participates are encouraged to give brief reports on their intentions during the parallel sessions at Santa Cruz

Physics and Detector Groups will begin evaluation of
initial and eventual energy reach integrated luminosity positron polarization how much is needed/useful gamma-gamma collisions electron-gamma collisions electron-electron collisions energy spectrum beam bunch structure other collider parameters

LC Detectors, Jim Brau, SLAC, May 31, 2002

49


Conclusions
The goals for the Linear Collider Detectors will push the state-of-the-art in a number of directions.
eg. finely segmented calorimetry for energy-flow measurement pixel vertex detectors (approaching a billion pixel system) integrated readout

Many detector issues remain to be understood and developed. Please get involved in the effort and help us prepare for the experiments come to the Santa Cruz LC Retreat, June 27-29
LC Detectors, Jim Brau, SLAC, May 31, 2002

50