News from Asia

1
News from Asia
28 July 2004 American LC Workshop Victoria,
Canada Sachio Komamiya Graduate School of
Science, University of Tokyo
2
Major ACFA Activities on LC

• 2003 February 12
• ACFA Linear Collider Symposium
• The GLC (JLC) Project Report was open to the
  public.
• 2003 April 17
• ACFA LC Seminar was held in CAT Inodor,
  India.
• ACFA selected GLC for the new project name.
• JLC ? GLC
• 2003 October 27
• The 8th ACFA Plenary meeting was held in
  National Synchrotron Radiation Research Center,
  Hsinchu Taiwan.
• (1) With an unanimous vote ACFA proposed KEK to
  be the Head-quarter of the GDO of the
  International LC Project.
• (2) Kurokawa is planning to stregthen the Asia
  wide collaboration
• by using the multi-lateral traveling
  budget of JSPS.

3

• 2003 December 15-17
• 6Th ACFA Linear Collider Workshop on Detector
  and Physics
• Tata Institute for Fundamental Research,
  Mumbai, India
• The program and talks are on
  http//www.tifr.res.in/acfa6/program.html
• 2004 April 1
• All National Universities in Japan and KEK
  become independent agencies.
• The accounting system has been changed. The
  system has more flexibility.
• The research budget is shifted to the
  competitive budget.
• 2004 April-May (After LCWS2004)
• Start discussion on the advantages and
  internationalization of the Huge /Truly Large
  Detector concept.
• 2004 May 25-26
• ITRP inspects KEK.
• Several high-powered weapons were found.
  
• 2004 November 9-12
• 7th ACFA Linear Collider Workshop on
  Detector and Physics

4
Organization of ALCSC
Executive Board Australia S.N.Tovey China
H.S. Chen India D.D.Bhawalkar
KEK Y.Totsuka Japan S.Komamiya
Korea J.S.Kang Taiwan W.S.Hou
Other V.V. Thuan
ACFA D.D.Bhawalkar
Accelerator WG
5
LC Executive Committee of KEK

• 2003 April Chair Hirotaka Sugawara ?Yoji
  Totsuka
• 2004 April Chair Fumihiko Takasaki
• Members 37 members
• KEK Administration
• Accelerator Physicists
  (KEKOther Institutes)
• Experimental Physicists
  (KEKUniversities)
• Since April 2001, about 30 meetings are held.
• Report LC RD results,
• Discuss on the international LC issues.
• Time to time extended committee meetings were
  held with participating non-Japanese ACFA LC
  members.

6
LC Forum of Japan

• Japanese Industries are very keen to be involved
  in the LC project.
• To promote LC by a collaboration of Industries
  with Research Institutes and Universities, we set
  up a forum under JHEPC October 2002.
• President Ken Kikuchi (former JSPS president)
• Secretary-General N.Ozaki (Techno-economy Lab.
  Thinktank)
• More than 50 major companies and more than 100
  academic researchers participate in the forum.
• Three working groups (Technology, Infrastructure
  and
• International affairs) are actively working.
• They send delegations to India, China, CERN,
  DESY, SLAC, Fermilab, BNL, LANL, ESRF, , to
  collect information on LC by themselves and also
  to advertise their products.

7
LC Forum of Japan (continue)

• The companies participated in this forum are
• Heavy industries (Hitachi, Mitsubishi,
  Kawasaki, IHI, Kobe Steel, )
• Electrical engineering (Toshiba, Mitsubishi
  El., NEC, )
• Electric devices (Hamamatsu, Nichicon)
• General construction (Takenaka, Taisei,
  Kumagai, Shimizu, Nikken,)
• Electric power (J-power,)
• ..
• Recently they have worked on the cost evaluation
  of LC accelerators for ITRP
• with accelerator physicists.
• Cold Machine
• Warm Machine (X-band)
• The prices for the items which have
  international-standards are stable. A large
  variations of the prices were found for the items
  which need more RD of the industrialization. The
  initial cost evaluation by the industry has large
  safety factors for the yield rate which cannot be
  estimated at this stage.
• ?ITRP is wise enough to decide that the cost
  issue cannot be included in the process of the
  recommendation of the technology.

8
Detector Issue

• We are thinking a Huge/Truly Large Detector
  concept.
• The idea of detector concept is defined to be
  global and not regional. We try to
  inter-regionalize the concept and the RD
  activities.
• There are so many advantages to have a truly
  large detector which has a good balance on
  charged particle and neutral particle
  measurements.
• This concept is based on our experiences at
  PETRA, PEP, TRISTAN, SLC and LEP, and recent
  studies.

9
Philosophy of the Huge Detector

• The detector which can make detailed studies of
  individual particles will finally win the game.
• In addition to the W and Z mass resolution
  (recoil/direct), Vertex resolution, and jet
  energy flow measurements,
• to reconstruct individual tracks (including
  low momentum ones) in B-hadrons or taus in
  Higgs/SUSY decays are crucial to establish the
  physics principles.
• Particles should be widely separated at the E-cal
  inner surface.
• essential for the jet energy (particle) flow
  measurements
• Hermetic Detector
• Relative fraction of dead space (for cabling
  or segmentation) can be made smaller.
• It is still smaller than the CMS detector.

10

• Figure of merit Main Tracker

The momentum resolution at lower energies is
determined by multiple scattering
11
B0
12

• Figure of merit Calorimeter
• sjet2 sch2 sg2 snh2 sconfusion2
  sthreashold2
• Separation of charged particles and g/nh is
  important (See H.Videaus talk at LCWS2004)
• Charged particles should be spread out by B field
• Lateral size of EM shower of g should be as small
  as possible ( Rmeffective effective Moliere
  length)
• Barrel B Rin2/ Rmeffective
• Endcap B Z2/
  Rmeffective
• Rin Inner radius of Barrel ECAL
• Z Z position of EC ECAL
  front face
• (Actually, it is not so simple. Even with B0,
  photon energy inside a certain distance from a
  charged track scales as Rin2)

13
Merits of Huge Detector

• Good Jet Energy (Particle) Flow Measurement
• Good charged track separation in a jet at the
  inner surface of the calorimeter
• large BR2
• Pattern recognition is easier
• large n with thin material, small number
  of low momentum curling tracks
• Good momentum resolution for charged particles
• large BR2 vn
• Good dE/dx measurement for charged particles
• large n
• Smaller relative volume of the dead space
• small ?V/V for constant ?V ? n
• Two track separation, Larger efficiency for Ks
  and ? (any long lived)
• large BR2 , larger R

14
Challenges

• Gas detector for the main tracker is robust
  against background ?
• Optimize the inner radius, insert
  intermediate Si-tracker
• (the background environment is far less
  severe than for LHC)
• Silicon Vertex Inner radius (due to the lower
  magnetic-field) ?
• Any essential impact on physics ?
• Stored Energy of Magnet ?
• Energy ? B2V
• Cost of calorimeter ?
• Number of channels is similar to other
  detector designs
• Mechanical support including Final-Q ?
• Longer L in the new FF optics
• ?Many challenges are good for new Participants.
• Easier life will spoil the LC community.

15
Vertex Detector Issues
of fired pixels 5.0 pixels/hit

• TRC500 beam parameters

• Compared to 4T case, pair background hit at R
  15mm becomes x1.7 larger in 3T
• At larger R, the background hit would decrease
  significantly
• The configuration of R20 mm with Si thickness lt
  70 mm and 500 mm thick beam pipe at R12 mm still
  satisfies the requirement of
• sb5 ? 10/(pbsin3/2q) mm

16
Impact parameter resolution
(Y.Sugimoto)
R(mm) tSi(mm)
Impact parameter resolution (mm)
Beam Pipe R12 mm (fix), t500 mm
Momentum (GeV/c)
17
Uniformity of the Magnetic Field
20003000tons
18
Magnetic field calculation (by Yamaoka)
7m
5.3m
4.85m
8.3m
4.5m
R4m
4.25m
3.55m
2.35m
2.05m
R0.6m
0.4m
19
Uniformity of the Magnetic Field
R0.4m
R1.0m
R1.8m
R2.05m
20
Interaction Region
21
EM Calorimeters

• Area of EM CAL (Barrel Endcap)
• SD 40 m2 / layer
• TESLA 80 m2 / layer
• LD 100 m2 / layer
• (JLC 130 m2 / layer)

22
Global Geometry
23
Comparison of Detector Models LD Minimally
modified one
24
Comparison of Detector Models
25

• The LC detector optimized for Energy Flow
  Algorithm is realized with a Huge/Truly large
  detector
• There are a lot of space for improvements/challeng
  es.
• A global efforts are needed and we are
  looking for equal footing partners in the world.
• The smaller detectors are not always inexpensive.
• The key is
  Calorimeter

26
CLIC/CERN Issue viewed from Asia

• Since the influence of the CERN (council) to the
  European (or world) financial agencies for HEP is
  very large, if CERN is not positive for the
  current Linear Collider project, the project
  cannot be truly global, and a fatal effect on the
  schedule might be caused.
• The CLIC (two beam) technology is very important
  for the future HEP activities, but it is
  premature to be compared with the warm/cold ones.
  The important physics at lower energies (Higgs
  studies etc.) are in any case crucial to the
  further steps.
• Its importance is absolute and the LHC
  discoveries can only encourage it.
• Since a large fraction of the HEP community is
  very positive for the current LC project, it is
  also important for CERN to support the project.
  The HEP community has been extensively supporting
  LHC. We fully understand that they need to
  concentrate on LHC, and have little budget for
  supporting the current LC project. The way CERN
  to support the current LC project not necessarily
  a financial one. We need a world-wide pressure
  to convince the financial agencies for this
  project.
• We should think not only a short-term financial
  strategy. We need to establish a stable and
  global mechanism for the long-term commitment of
  the global LC project.
• Therefore, a moral support by CERN is
  essential at this moment.

Continuous discussions with CERN are necessary in
every layers to establish a long term strategy
for the LC project.
27
Summary

Whatever the accelerator technology
recommendation has been made by ITRP by the end
of this year (or soon), Asian physicists will
continue to make efforts towards the truly global
linear collider project. Based on the past
fruitful experiences in the international HEP
collaborations, we keep supporting the the
bottom-up activities of the World-wide Studies.
A Huge/Truly Large Detector concept (it is
still smaller than the LHC detectors) is
proposed and the studies have to be globalized.
Firm detector collaborations should not be
established at this stage, since we should
attract more physicists who are not directly
participated in the LC working groups.