BESIII Physics and

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BESIII Physics and Detector Overview Internatio
nal BESIII Workshop Weiguo Li IHEP, Beijing,
Oct. 13, 2001
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• BES Detector and Physics Achievements
• Physics at BEPCII/BESIII
• BESIII Detector Overview
• Summary

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BESII Detector and physics achieved
VC ?xy 100 ?m BTOF ?T
180 ps (gt330 ps) MDC ?xy 250 ?m
BSC ?E/?E 20 ,?z 3.0 cm
?dE/dx 8.4 ? counter ?z
5.0 cm
DAQ readout lt 10 ms
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Major parameters of the BES detector
performance Detector Major para. BESI
BESII VC ?x,y (?m)
200 100 MDC ?xy (?m)
200-250 220
?p/p () 1.78 ?(1p2) 1.7 ?(1p2)
?dE/dx() 7.9
8.4 BTOF ?T (ps) 375
180 BSC ?E/?E ()
23.8 20.3 ?z
(cm) 4.5
3.0 Muon ?z (cm) 5.0
5.0 DAQ dead time/event
(ms) 20 lt10
BESII from 1996
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Data Collected with BESI and BESII
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World J/? and ?(2S) Sample (106)
Largest from BES
J/?
?(2S)
2001
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The BES Collaboration
Korea (3) Korea University Seoul National
University Chonbuk National University
USA (4) University of Hawaii University of Texas
at Dallas Colorado State University Stanford
Linear Accelerator Center
UK (1) Queen Mary University
Japan (4) Nikow University Tokyo Institute of
Technology Miyazaki University KEK
China (15) IHEP of CAS Univ. of Sci. and Tech. of
China Shandong Univ., Zhejiang Univ. Huazhong
Normal Univ. Shanghai Jiaotong Univ. Peking
Univ., CCAST Wuhan Univ., Nankai Univ. Henan
Normal Univ. Hunan Univ., Liaoning Univ.
Tsinghua Univ., Sichuan Univ.
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BES Entries in PDG 2000
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Citations of BES Papers
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High Lights of BES Physics Results

• Precise t mass measurement
  MeV/c2
• 2-5 GeV R measurement, better prediction for
  Higgs mass, 61 ? 90 GeV, upper limit 170 ? 210
  GeV
• J/? physics, hadron spectroscopy, search for
  glueball, hybrids and exotics
• ?(2s) physics, new measurements of ?(2s) and ?c
  decays, 15 rule, ?? suppression
• DS ? D physics, leptonic, semileptonic and
  absolute Brs

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Recent preliminary results

• Study of the structure around 1.7 GeV mass region
  
• in J/? ? ?KK- , to be 0 state
• Systematic study and PWA analysis of J/? ?
• ???-, ?KK- , ???-, ?K K- , ???-, ?KK-
• Analyses the properties of ? from J/? ? ???-
• Study of excited baryonic states (N, ?)
• - Pure isospin 1/2
• -Large branching ratio 10-3
• More results are expected with 50M J/? events

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First Measurement of B(?(2S)???-)(hep-ex/0010072
)

• B(?(2S)???-) 2.71?0.43 ?0.55 (BESI)
• Test of universality Bee?? B? ? ? B? ?/0.3885 ?
  Bll
• Bee
  B? ? B? ?/0.3885
• 8.8 ? 1.3 10.3 ? 3.5 7.0 ?
  1.1 ? 1.4
• Obtain ?tot
• PDG ?ee 2.12 ?0.18 keV
• ?tot ?ee/Bll 252 ? 37 keV

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Scan of ?(2S) peak 24 energy points between 3.67
and 3.71 GeV Int. L 760 nb-1
Improve the parameters of ?(2S) ?, B(h), B(?
?-), B(??-J/?) B(??-X)
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Running Plan before 2004

• BEPC will take data with BESII at least until
  2004
• - 12 M ?(2S) events/year
• - Precision measurement of R in 2-3 GeV
• - ?(3770)?
• Afterwards, a long shutdown will be scheduled
  for the installation of BEPC II.

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Physics to be studied at ?-charm region

• Search for glueball, quark-gluon hybrid and
  exotic states
• Charmonium Spectroscopy and decay properties
• Precision measurement on R value
• Tau physics tau mass, tau-neutrino mass, decay
  property, Lorenz structure of charged current, CP
  violation in tau decays
• Charm physics including decay properties of D
  and Ds, fD and fDs , D0 D0 mixing and CP
  violation

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• To answer these physics questions, key issue is
  precision measurements with
• High statistics data samples
• Small systematic errors
• ?
• Future development of BEPC/BES
• High luminosity machine
• High performance detector
• adapts to high event rate
• provides small systematical errors

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From BESII to BESIII

• The Shortcomings of BES II Detector
• Poor energy resolution for electrons and
  photons
• Marginal charged track momentum resolutions
• TOF counters too wide, multiple hits in one
  counter
• Information from endcap detector is not
  sufficient for
• phys. analysis
• Endcap not easily openable to fix detector
  problems
• Muon coverage too small.

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• Upgrades Needed for BEPCII/BESIII
• BEPCII with multi bunches and smaller beam size,
• BES needs
• Upgrade DAQ system with pipeline scheme, to
  accommodate a factor of more than 200 event rate
• As the beam size (Z) reduced from 4-5 cm to
  1-1.5 cm, there is room to further improve TOF
  time resolution.

Generally speaking, as the statistical errors
become smaller with larger samples at BEPCII, a
better detector is needed to improve the
systematic errors, BESIII will be almost
completely a new detector.
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Physics at BEPCII/BESIII

• Rich of resonances, charmonium and charmed
  mesons
• Transition between perturbative and
  non-perturbative QCD
• Charmonium radiative decays are the best lab to
  search for glueballs, hybrids and exotic states

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Expected Event Rates/Year at BES III
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• J/? Physics
• 1. Glueball search
• criteria for glueballs
• no place in nonet
• enhanced production in gluon rich processes
• decay patters incompatible with states
• reduced ? ? couplings
• masses, quantum numbers consist with lattice QCD

Candidates for glueballs f0(1500), fj(1710),
?(2230) , etc.,
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Red ordinary Green interesting non-
states Black other states not fitting in
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Lattice QCD Numerical Calculation of Glueball
Masses 0 IBM 1740 ? 71 MeV
(1994) ? 1632 ? 49 MeV (1998)
UKQCD 1568 ? 89 MeV (1993) ? 1611 ? 30
? 160 MeV (1998) improved 1600 ? 100 MeV
(1997) ? 1730 ? 50 ? 80 MeV (1999)
IHEP(Wu)
1757 ? 100 ? 86 MeV (2001) 2
Meachel 2332 ? 88
MeV (1989) UKQCD
2270 ? 100 MeV (1993) IBM
2359 ? 128
MeV (1994) Morningstar
2140 ? 45 MeV (1997)
Morningstar 2400 ? 25 ?
120 MeV (1999) IHEP(Wu)
2417 ? 84 ? 117 MeV (2001)
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2. Hunting for hybrids Searching for states
with exotic quantum numbers, 0-, 0--, 1-,
2-, 3-, J/? ? ?x, x ? ??? or
5?, or ??0, or ?3? J/? ? ?x, x
???(1300) or ?a1(1260) or KK1(1400) with ?(1300)
and a1(1260) decay to ? ? 3. Other interesting
topics
Nature of f0(980) Searching for glueballs and
hybrids through?(2s) ? ? ?c
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Searching for 1- state
producing J/? ? ?x, x ? ??0, X are mixing of
f0(980), a2(1320), ?(1390), ?(2300), here ?(1390)
is 1- state
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• ?(2S) Physics
• BESII may collect 1.6 ? 107?(2S) events.
• and BESIII 2 ? 109 ?(2S)
  events/year.
• Hadronic decays, systematic study of decays with
  better BR measurements, 15 rule, VP, VT and
  other modes
• BR uncertainty 10-30 ? a few
• Radiative decays, search for glueballs, etc
• ?c decays, systematically measure BR
• BR uncertainty 10-30 ? a few
• Upper limits will be improved by two orders

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• search
• Assuming the Br is the same for and ?c
• with 3 ?109?(2s), fast simulation shows,
  using 3? 2P in
• 
  --------------
• about 600 signal events can be selected, and
  there are about
• 12 background events from corresponding ?c
  decays.
• 1P1 search
• From ?(2s) ? ?0 1P1 ? ? ? ? ?c ? ? ? ? 4K
• with 3 ?109?(2s), fast simulation shows,
• about 250 signal events can be detected, with
  about 8 background events.

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Signal for (598)
background(12) With 3 ?109 ?(2s) produced
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Signal for 1P1 (248)
background(8) With 3 ?109 ?(2s) produced
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• Charmed Meson Physics
• Low background, simple events, using D, Ds
  tagging,
• can have lower systematic errors to study
• Pure leptonic decays. fD , fDs
• Semileptonic decays ,
• Non-leptonic decays
• One year run at (3770) or 4.03 GeV, a few
  percents statistically
• mixing through ( )
  ( )

Lower statistics compared with B factories Need
careful study to evaluate physics reaches and
make comparison
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Decay Input Measured
Stat. Stat. Total
Mode Value Value Error
Error Error
80 pb-1 80 pb-1
1000 pb-1 PDG
3.7 3.59?0.15 4.2
1.2 2.3
7.8 8.12?0.34 4.2
1.2 4.1
7.7 7.80?0.40 5.1
1.4 6.7
2.8 2.99?0.17 5.7
1.6 9.0
5.6 5.16?0.32 6.2 1.8
12.8
0.69 0.75?0.05 6.7 1.9
8.0 3.4
3.33?0.17 5.1 1.4
4.9 0.4
0.37?0.06 16.2 4.6
16.2
7 ? 3 events
90 ?10 events for 1000 pb-1 (4000 pb-1 /y)
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With one side semi-leptonic decay, the other
tagged D mass distribution
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• t Physics
• Threshold production, without open charm
  background
• one year data taking at 3.57 GeV or 3.67 GeV will
  produce
• about 2-10 million t events, with small
  backgrounds
• CP violation in t decays, with 427 pure leptonic
  decay e? events collected at 4.03 GeV, A ? a few
  percent
• more events( a factor of 100) and more decay
  channels will give better results
• precise tmass and t neutrino mass measurement
• t Decay studies

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• Study Baryonic Excited States (N , ? , ? and
  ? ) from J/? and ?(2s) Decays
• Complementary to experiments at CEBAF, GRAAL
  
• and SPRING8
• Can systematically study the excited bayrons
• Can reveal the quark-gluon structure of matter

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Re-measure R-values in BEPC Energy Range The
contribution to the ?(MZ2) from R-value remains
to be significant. After R values at lower energy
get measured accurately, from VEPP-2M in
Novosibirsk and ? factory in Frascati (1level),
it is worth while making the R measurement in
BEPC energy range with an uncertainty of 3,
should check if 1 level is possible? . Should
try to maintain this possibility in the design of
BEPCII.

• Study of QCD and hadron production in BEPC
  energy region

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The Impact of BESs New R-Values on the SM Fit
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• Searches and Possible New Physics
• Lepton flavor violating J/? decays
• J/? ? e?, e?, ? ?
• J/? decay to DX
• CP violation in J/? decays

• With more than 109 J/?and ? events, the upper
  limits for rare and forbidden decays,
• Br measurements can reach the level of 10-610-7

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• At Hadron2001 held in Protvino of Russia,
• Fermilab pbar p experiment admitted that, the
  signals of
• 1P1 and are not confirmed, with a factor
  of 3 more luminosity than before.
• VES stated that the 1- signal of ?1(1400)
  found before, should be explained
• as the feed down of the nearby peak, for
  ?1(1600) there is still possibility it is
• a 1- state, but VES played down the
  significance.
• On the other hand, BNL E852 still hold the 1-
  signals are true.
• So the situation becomes more uncertain, it
  gives BES more
• chance to make discoveries, but it also tells
  that the hadron
• physics is very complicated.

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BESIII Detector Overview According to the
current plan, among the detector components,
almost every component Should be replaced with
new detector. The new detector design is very
much affected by using retired L3 BGO crystals as
the barrel calorimeter.
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Schematic of BESIII detector
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Major Upgrades in BESIII

• Superconducting magnet
• Calorimeter BGO with ?E/E 2.5 _at_ 1GeV
• MDC IV with small cell, Al wires and He gas
• Vertex detector Scintillation fibers for
  trigger
• Time-of-flight ?T 65 ps
• Muon detector
• New trigger and DAQ system
• New readout electronics

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Scintillating fiber for Trigger

• 1.27 mm or thinner Be beam pipe may be used
• R 3.5 cm
• 2 double-layers one axis layer and one stereo
  layer
• Scintillating fiber 0.30.3 mm2, L60 cm
• Clear fibers 0.30.3 mm2, L1.4 m
• two side readout by APD (F3) (below 300)
• Signal/noise lt6 p.e.gt / lt1p.e.gt
• ?? 50 ?m ?z 1mm
• Total of channels 27 x 8 216

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Main Draft Chamber

• End-plates with stepped shape to provide space
  for SC quards and reduce background
• Inner part stepped conical shape, cos ? 0.93
• Outer part L 190 cm, cos? 0.83 with full
  tracking volume
• cell size 1.4 cm x 1.4 cm
• Number of layers (cell in R) 36
• Gas HeC2H6 , or HeC3H8
• Sense wire 30 ?m gold-plated W ,
• Field wire 110 ?m gold-plated Al
• Single wire resolution 130 ?m
• Mom. resolution 0.8 _at_ 1GeV 1T, 0.67
  _at_1GeV1.2T
• DE/dx resolution 7

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Trackerr simulation of MDC, ?pt as a function of
pt in for pion, wire resolution 130 ? m
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Trackerr simulation of MDC, ?pt as a function of
pt in for pion, wire resolution 100 ? m
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PID Time of Flight Counters

• Double layers TOF ( or TOF CCT)
• plastic scintillator (BC-404)
• 80 pieces per layer in ?
• R 66 75 cm,
• Thickness 4 cm, length 190 cm
• Readout both sides by F-PMT
• Time Resolution 65 ps
• 2son k/? separation
• 1.11.5GeV/c (for polar angle 00 450)
• For CCT option, need RD

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TOFTOF
TOFCCT
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BGO Barrel Calorimeter

• To provide minimum space for main draft chamber
  and TOF and to obtain the necessary solid angle,
  one must modify L3 BGO crystals, and add new
  crystals
• 13 X0 ?E/E 2.5 _at_ 1GeV
• Rin 75cm , Lin 200cm cos ? 0.83
• Cut L3 BGO crystals (10752) 22 X0 (24cm)
  into 13X0 (14cm) 8.5 X0(9.5cm)
• Making new bars of 14 cm
• by gluing 9.5cm new crystal of 4.5cm
• new BGO crystals needed.  

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• Endcap Detector
• Two possible technologies can be used,
• CsI crystals as in the detector figure, similar
  technology as in the barrel, need endcap TOF.
• 2. Similar technique as KLOE using lead-fiber
• technique, may not need TOF counters.
• The first choice is preferred.

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Superconducting Magnet for BESIII

• B 1 1.2 T,
• L 3.2 m
• Rin 105 cm, Rout 145 cm
• Technically quite demanding for IHEP,no
• experience before, need collaboration from
• abroad and other institutes in China, both for
• coil and cryogenic system.

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Muon Counter

• Barrel (L 3.6m ) Endcap cos? 0.9
• Consist of 12 layers stream tube or RPC
• Rin 145cm (yoke thickness 40cm)
• Iron plate thickness 2-6 cm
• ? counter thickness 1.5 cm
• Readout hits on strips 3cm
• total weight of iron 400 tons

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Muon acceptance
Pion contamination
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• Interaction Region
• It is very compact at IR, very close cooperation
  is needed in the designs of detector and machine
  components at IR
• Understand the space sharing, the support,
  vacuum tight
• Understand the backgrounds from machine and how
  to reduce them,
• - Beam loss calculation (masks)
• - Synchrotron radiation (masks)
• - Heating effect (cooling if necessary)
• Understand the effects of the fringe field from
  SCQ to the detector performances

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• Luminosity Monitor
• Because the situation at the IR, the luminosity
  has to either
• be located quite far away from the IR (3-5m), or
  in front of
• Machine Q magnet, to be designed carefully.
• Accurate position determination
• Multiple detection elements at each side to
  reduce the
• variation of luminosity when the beam position
  shifted
• BGO crystals ?

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• Trigger
• Trigger rate estimation
  (using the same
  trigger conditions as now)
• Background rate, with 40 times beam current and
  half of the beam lifetime, the rough estimation
  for the background is 80 times the current rate
  (10-15), or 800-1200 Hz, taking 1500 as a design
  number
• Good event rate

When leave room for maximum luminosity to be as
calculated, 1?1033, 200 times as current event
rate, to be 1500 Hz

• Cosmic ray background can almost be negligible

Total peak trigger rate can be more than 3000 Hz,
additional trigger (software) is needed to reduce
the event rate to 2000Hz.
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Level 0 and 1 are hardware triggers, latency
2.4?s, Level2 is software filtering using
online computing farm Because fastest detector
element TOF need a time window of about 30 ns,
the trigger can identify bunch train only, not
individual bunch

• Level 0 with TOF signals
• Level 1 with hardware track finding, EMC
  clustering, total EMC energy, VC tracking or
  hits, ? counter hits

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• Front-end Electronics
• Pipeline scheme is required
• Requirements
• For the timing measurement
• 25 ps for TOF, 0.5 ns for MDC
• For charge measurement
• 1 accuracy for EMC, 2 for MDC and TOF
• Total number of electronic channels 76800 (too
  many muon channels?)

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Data Acquisition System Event builder 3000 Hz ? 6
K bytes 20 Mb/s Event filtering Data
storage Run control Online event monitor Slow
control
Switch network
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• Offline Computing and Analyses Software
• Computing, network, data storage, data base,
  processing management
• Supporting software package, data offline
  calibration, event reconstruction, event
  generators, detector simulation

Total CPU 36000 MIPS Data storage 500 Tbytes/y
on tapes, 24 Tbytes/y on disks Bandwidth for data
transfer 100 Mbps
Substantial manpower needed for software
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Major New Subsystems of BESIII

• Vertex chamber ZHANG
  Qinjian
• Main drift chamber CHEN
  Yuanbo
• Time of flight counter HENG
  Yuekun
• EMC shower counter LU
  Jungguang
• Luminosity monitor WU Jian
  (USTC)
• Trigger system LIU
  Zhenan
• Front-end electronics SHENG Huiyi, ZHAO,
  Jingwei
• Data Acquisition HE
  Kanglin
• Computing and software MAO Zepu

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• Detector RD
• A lot of new detector technology
• RD for most sub-systems started
• Detector optimization is needed
• Modify the detector design when international
  collaboration is formed, new ideas are mostly
  welcome

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Cost Estimation

• Detector 220M Chinese Yuan ( 30 M US )
• 2/3 to 3/4 are from Chinese Government
• International collaboration and contribution
  are needed

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• Cost estimation of Detector subsystem
  (Preliminary)
• In M RMB (1 USD 8.3 RMB)
• Beam pipe vertex chamber
  3.0
• MDC
  11.0
• TOF
  6.0
• Barrel EMC
  54.0
• Endcap EMC
  20.0
• Barrel Muon detector
  4.5
• Endcap Muon detector
  2.5
• Super conducting magnet
  45.0?
• Luminosity
  2.0
• Electronics
  63.0?
• Trigger and DAQ
  13.0
• Total
  224.0
• about 1/4 to 1/3 of the detector budget
  either be contributed other sources
• or be staged.

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Schedule

• Feasibility Study Report of BEPC II has been
  submitted to the funding agency .
• Technical Design Report of BEPC II to be
  submitted by first half of 2002.
• Construction started from Summer of 2002
• BESII detector moved away Summer of 2004, and the
  BESIII iron yoke started to be assembled, mapping
  magnet early 2005
• Preliminary date of the machine long shutdown
  for installation Spring of 2005
• Tuning of Machine Beginning of 2006
• BESIII detector moved to beam line, May 2006
• Machine-detector tuning, test run at end of 2006

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Intl. Cooperation on BEPC II / BES III

• Intl. cooperation played key role in design,
  construction and running of BEPC/BES.
• Intl. cooperation will play key role again in
  BEPC II / BES III design, review, key
  technology, installation, tuning
• Participation of foreign groups is mostly
  welcomed.
• BESIII should be an international
  collaboration,
• Establish organization accordingly.

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Welcome Chinese universities and research
institutions to participate in BESIII
project Design, MC simulation
Sub-detectors RD and construction
Electronics RD and manufacture
Online/Offline software Software
package Reconstructions
Calibration Physics
study In charge of some sub-system or send
people to IHEP
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• More Home Works
• More simulation to study the physics reaches
  with BESIII. magnet? solid angle coverage ?
• More study about the interplay between detector
  and machine, especially in IR
• More detector simulation to arrive design
  optimization
• Each system (detector components, DAQ and
  electronics) needs RD, prototypes
• Commissioning machine with detector outside beam
  line,
• radiation issue.
• about Cost and schedule
• Cost for EMC, SC magnet and electronics is most
  crucial
• MDC, EMC and SC magnet (including iron
  structure) on critical path

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• Major issues related with BESIII design
• The radius of crystal calorimeter, affecting
  performances and cost. Possibility of using CsI
  crystals as EMC.
• Backgrounds associated with machine operation,
  the design of interaction regions, vacuum, masks,
  etc.

Experienced man power big issue
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If not enough fund is expected, 2nd option
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Competition from CLEOC Serious challenge from
CLEOC project Design machine and detector to be
as advanced as possible, Complete the
BEPCII/BESIII project ASAP Collaboration between
BES and CLEO
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• Summary
• BEPC energy region is rich of physics, a lot of
  important physics results are expected to be
  produced from BESIII at BEPCII
• Detector design is started, need a lot of
  detailed work to finish detector design
• Very interesting and very challenging project

Thanks
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Thanks
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Design parameters for BTCF and BESIII detector
BTCF
BESIII Charged
particles ?p/p(GeV/c) 0.4p
0.4/? 0.7p 0.5/ ? ? (x 4 ?)
90 (all ), 95 to 4th 83(all),
93 to 4th Photons ?E/E(GeV) 1/
?E(GeV) 2 2.5/?E(GeV)
Angular resolution 2 mm/ ?E
3 mm/ ?E Particle ID TOF
50 ps (double TOF) 65 ps (double TOF)
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Summary

• BEPC/BES has well operated with many exciting
  physics results since beginning the operation in
  1989.
• There is a great physical opportunity, and
  challenge as well, for BEPC /BES which calls
  precision measurement.
• BEPCII is proposed as double ring micro-b with
  designed luminosity of 1?1033 cm-2s-1 at 1.55
  GeV.
• Major upgrade on BES detector, so called BES
  III.
• The project is technically feasible.
• Chinese Government agreed to support BEPC II.
• Intl. Participation to BEPC II / BES III is
  highly welcomed.

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• If BEPCII can reach the luminosity of 1033, then
  some of the physics intended for tau-c factory
  can be realized.
• At BTCF feasibility study, the main physics
  topics studied were,
• J/psi decays, to pin down the spin-parity of
  some glueball and exotic states, 109 to 1010
  events are needed, a luminosity of 5 1032 is
  needed.
• to measure the tau neutrino mass, 1033
  luminosity is needed, and the detector should
  have good mom. resolution and good ?/K
  separations, to reach a sensitivity 1 MeV

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• to reach 10-4 sensitivity,
  1033 luminosity is needed for a year, with very
  good ?/K is needed to reduce misidentification
  background.
• To renfirm 1P1 state, 5 1032 is needed for a
  year.
• To measure ? decay CP violation, very good mom.
  resolution of ?p/p (0.2-0.4)? 1p2 and good
  ?/K separations are needed, needs a luminosity of
  5 1032.
• For all these topics, good momentum resolution
  and good particle ID are needed

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Intl. Review on Feasibility Study of BEPC II (2
6 April 2001, Beijing)

• Two subcommittees prepared two reports
• - Machine 2 4 April, chaired by Prof. Alex
  Chao
• - Detector 4 6 April, chaired by Prof. M.
  Davier
• Joint meeting on the design of IR 4 April.
• Summary by Prof. W.P. Panofsky
• A large amount of excellent professional work
  has been accomplished by the IHEP team, leading
  to the Feasibility Study Report on BEPC II.

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Summary by Prof. W.P. Panofsky (cont.)

•    There is no basic reason why a luminosity
  greater than 3 x 1032 or even 1033 cannot be
  reached in accelerator accommodated in present
  BEPC tunnel.
• Strong preference for the two-ring option.
• Intl. participation in BEPC II is highly
  desirable. An aggressive program promising
  unique performance in the tau charm region would
  be helpful in promoting intl. participation.
•    Intl. participation in BES III detector would
  be of great value both in sharing costs and in
  scientific contributions. A workshop exploring
  the physics potential of BEPC II and addressing
  BES III design issues would be highly useful.

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Endcape EMC

• Lead-Scintillating fiber ?E/E 6E-1/2
• Scintillating fibers ? 1 mm
• Volume ratio of fiber lead glue 50428
• Readout both side by F-MPTs ( ? 1.5)
• Cell size 4.5cm2/PMT
• Direction of scint-fiber up-down
• Readout layers in Z direction 4
• Rout 90cm, Rin 36cm
• Totalscint-fiber 500Km
• Total channels 768

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Cost Estimation Here very rough estimation is
given, better numbers will be obtained after
prototypes are made Detector subsystem
Cost estimation(MRMB) Vertex chamber
(beam pipe) 2.95 Main drift
chamber 13.58 Barrel
TOF
7.0 Barrel EMC
64.95 Muon
2.7 Luminosity
2.0 Endcap EMC
20.0 FED
electronics
74.6 (2000RMB/channel) DAQ system
15.0 Total cost
202.78
The cost for HEP manpower and offline computing
are not included

BESIII is expected to be ready in the year of 2005
94
BES Entries in PDG 2000
Page
95
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96
Invariant Mass Spectrum of ?0 ?0 from J/?
Radiative Decay
97
(No Transcript)
98
Scan with proper spin-parity distributions
2 input mass 1320
MeV, width 100 MeV
99
1- input mass 1390 MeV,
width 390 MeV