BEPCII/BESIII - University of Hawaiifah/bestalks/DPF06c-fah.pdf · 1/29/2008 DPF2006 1 Frederick A....
Transcript of BEPCII/BESIII - University of Hawaiifah/bestalks/DPF06c-fah.pdf · 1/29/2008 DPF2006 1 Frederick A....
1/29/2008 DPF2006 1
Frederick A. HarrisFrederick A. HarrisUniversity of HawaiiUniversity of Hawaii
For the BES CollaborationFor the BES Collaboration
BEPCII/BESIIIDPF 2006Oct. 30 – Nov. 3, 2006Honolulu, HI
The Beijing Electron Positron Collider (BEPC)
L ~ 5 ×1030 /cm2⋅s at J/ψ peak Ecm~ 2 - 5 GeV
A unique e+e- machine in the τ-charm energy region until CLEOc.
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BEPCII: a high luminosity double–ring collider
SC RF
Beams
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BEPCII Design goal
Energy range 1 – 2.1 GeV
Optimum energy 1.89 GeV
Luminosity 1 x 10 33 cm-2s-1 @ 1.89 GeV
Injection Full energy injection: 1.55 − 1.89 GeV Positron injection rate > 50 mA/min
Synchrotron mode 250 mA @ 2.5 GeV
Use many bunches and mini-beta.
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Design Goals and Main ParametersParameters Unit BEPCII BEPC
Operation energy (E) GeV 1.0−2.1 1.0−2.5 Injection energy (Einj) GeV 1.55−1.89 1.3
Circumference (C) m 237.5 240.4 β*-function at IP (βx
*/ βy*) cm 100/1.5 120/5
Tunes (νx/νy/νs) 6.57/7.61/0.034 5.8/6.7/0.02 Hor. natural emittance (εx0) mm⋅mr 0.14 @1.89 GeV 0.39 @1.89 GeV Damping time (τx/τy/τe) 25/25/12.5 @1.89 GeV 28/28/[email protected] GeV
RF frequency (frf) MHz 499.8 199.533 RF voltage per ring (Vrf) MV 1.5 0.6−1.6
Number of bunches (Nb) 93 2×1 Bunch spacing m 2.4 240.4
Colliding 910 @1.89 GeV ~2×35 @1.89 GeV Beam current SR
mA 250 @ 2.5GeV 130
Bunch length (cm) σl cm ~1.5 ~5 Impedance |Z/n|0 Ω ~ 0.2 ~4 Crossing angle mrad ±11 0
Vert. beam-beam param. ξy 0.04 0.04 Beam lifetime hrs. 2.7 6−8
[email protected] GeV 1031cm-2s-1 100 1
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BEPCII Status• BEPCII linac installation completed in 2005; most design specifications reached.
• Storage ring: Major magnets, superconducting RF cavities and quadrupolemagnets, as well as the cryogenics system have been completed, and theirinstallation is nearly complete.
• SR runs before the end of this year.
• Beam collisions expected in summer/fall 2007.
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BESIII Detector
Be beam pipe
SC magnetMuon Counter
Drift Chamber
CsI(Tl) calorimeter
TOF
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MDCParametersR inner: 63mm ; R outer: 810mm Length (out.): 2582 mm Inner cylinder: 1.2 mm Carbon fiberOuter cylinder: 11.5 mm CF with 8 windowsSense wire : 25 micron gold-plated tungsten (plus 3%Rhenium ) --
- 6796 Layers (Sense wire ): 43
Expected performance
Field wire: 110 micron gold-plated Aluminum --- 21884Gas: He + C3H8 (60/40)Cell: inner chamber --- 6 mm
outer chamber --- 8.1 mmPolar angle: |cos θ| < 0.83 (all layers)
< 0.93 (20 layers)%6~
@1GeV/C%5.0~
130~
dxdE
P
m
dxdE
P
x
σ
σμσ
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MDC
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MDC Status: Wire Stringing CompletePreamp installation in progress.
Cosmic ray running in about one month.
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Beam test at KEKPrototype tested in a 1T magnetic field
at KEK 12GeV PS. Results:• spatial resolution better than 130 µm• cell efficiency over 98%• dE/dX resolution better than 5%
(3σ π/K separation exceeding 700MeV/c).
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CsI(Tl) crystal calorimeter• Design goals:
– Energy: 2.5% @ 1GeV– Spatial: 0.6cm @ 1GeV
• Crystals:– Barrel: 5280 w: 21564 kg– Endcaps: 960 w: 4051 kg– Total: 6340 w: 25.6 T– 5 x 5 cm2 front face; 6.5 x
6.5 cm2 back– 28 cm length (15 radiation
lengths)• Have all barrel and most endcap
crystals
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Readout: Two Hamamatsu S2744-08 10 mm x 20 mm photodiodes
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Testing:•Size•Source tests (137 Cs)•LED tests•PD tests•Preamp tests•Cosmic ray tests•Beam tests (6 x 6 array):
X position
ADC
CsI Calorimeter
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Mechanical structure
A 1/60 prototype
Mechanical structure now at IHEP
Status:• Assembly starts
soon. Barrel completed by April 07.
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TOFCrucial for particle ID• Barrel
– 50mm x 60mm x 2320 mm (inner layer).
– BC408 – 2 layers – 88 in each
• Endcap– 48 fan shaped pieces –
each end.– BC404
• PMT: Hamamatsu R5942– Fine mesh
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TOF Performance
Time resolution 1-layer (intrinsic):
Belle: 70 to 80 psBeam tests: < 90 psSimulation: < 90 ps
Time resolution of two layers is 100ps to 110psfor kaon and pions.
K/π separation: 2 σseparation up to 0.9 GeV/c.
Capability of K/π separation
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TOF Monitoring System
TOF endcap 48 fibersTOF endcap 48 fibersLaser Light splitter
TOF barrelPMT PMT
Ref. PMTTDC startADC gate
Fiber
TOF barrel 176 fibersTOF barrel 176 fibers
Electronic switch
fiber
Fiber bundles
connector
Monitor the amplitude and time performance of each channel including PMTs and electronics. Being built by University of Hawaii:
Use mirror to steer beam – like BESII.Purchase fiber cable bundles (2 cables).
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Fiber Bundle Cables (need 2)Barrel TOF
EC TOF
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Test Setup at UH• Need TOF counter and readout
for testing TOF laser calibration system.
• Use Belle BC408 TOF counter and 2 BES fine mesh phototubes.
• Test with cosmic ray telescope.• Caen VME TDC and QDC with
computer to readout.• Next install fibers and pulse with
N2/dye laser.
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Coil: single layer solenoid Cooling mode: two phase helium force
flowSuperconductor: Al stabilized NbTi/CuWinding: inner windingCold mass support: tension rodThermal shield: LN2 shield, MLIFlux return: barrel/end yoke, pole tip
Superconducting MagnetCryostat
Inner radius 1.375m
Cable dimension 3.7mm*20mmElectrical parameters
Central field 1.0TNominal current 3650A
Stored energy 10MJCold mass 3.6tonTotal Weight 15ton
Inductance 2H
Radiation thickness 2X0
Outer radius 1.7mLength 3.91m
CoilMean radius 1.482mLength 3.52m
First of its kind built in China.
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BESIII Magnet ProgressThermal insulation assembly
transportation
wiring
installation
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0 500 1000-0.018
-0.016
-0.014
-0.012
-0.010
-0.008
-0.006
-0.004
-0.002
0.000
0.002
0.004
0.006
VTL1A-VTL2A VTLL1A-VTLL2A VTLL1B-VTLL2B VTLL3A-VTLL4A VTLL3B-VTLL4B VTM6A-VTM1A VTM6A-VTM5A VTM1A-VTM2A VTM3A-VTM4A VTM4A-VTM5A
Vol
tage
(V) Time:22:00Time:19:00
Voltage curve shows that the magnet is in super-conducting state.
Magnetic field 10029.8 Gauss.
BESIII Magnet ProgressSept. 19, 2006
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Muon Chamber
Barrel + EndCap;
RPC as μ detector;Barrel : 9 layersEndCap: 8 layersOne dimension read-out strips;
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RPCs• Electrodes made from a special type of phenolic paper
laminate on bakelite.• Have good surface quality(~200nm).• Extensive testing and long term reliability testing done.• Have high efficiency, low counting rate and dark current,
and good long-term stability .
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(RPC module)• Total of 64 endcap modules, 72 barrel modules;• Gas: Ar:C2H2F4:Isobutane = 50:42:8• HV voltage: 8000V;• One module contains two RPC layers and one readout layer.
1/29/2008 DPF2006 27Spring 2005: All RPC production, assembly, testing, and installation completed.
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Test Result after installation - endcapAverage strip efficiency: 0.97 Spatial resolution: 16.6mm
Mean of 64 endcapRPC = 0.95
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μ/π Identification Efficiency
0
10
20
30
40
50
60
70
80
90
100
0. 5 0. 75 1
Using Muc Info only
%
GeV/c
90.3
6.24
5.59.0
12.618.9
12.0
91.287.6
π fake rate
μ efficiency
Ratio of π decay to μbefore entering Muc
Design Goal
15.09.0 6.0
From Simulation
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Trigger and DAQ• The trigger design is almost finalized; pipelined and uses FPGAs. • By end of the year, all the boards should be tested.• Whole DAQ system tested to 8K Hz for the event size of
12Kb, a factor of two safety margin. • Whole DAQ system tested during beam test with MDC and EMC.
L1 trigger rate: 4 KHzEvent Size: 12 KBytes
Expected bandwidth after L1: 48 MByte/sec
Dead time: < 5%
1000 * BESII DAQ system
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Offline software
HepEvt McTruthG4Event
HitsDigitsRawDataCnvSvcBES I I I RawData
Generator EventConverters Simulation
Digitization
ReconstructionAlgorithms
CalibrationAlgorithms RecHits RecTracks
AnalysisTools DstTracksHistograms
Ntuples
RootDstCnvSvcDstData
Rec2DstAlgReconstruction
Calibration &Database
Framework CoreSoftware
Simulaton
Physics AnalysisSoftware
BES III Software
BOSS – BES Offline Software Systembased on Gaudi.
Tremendous amount accomplished so far.Much more to do.
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Event Display Tool: BesVis
Based on ROOT, OpenGL, X3D and XML
Support both 2D and 3D view
Operations and controls available through menu and toolbar items
First version was released in December 2005.
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SIMULATION – Based on Geant4
MDC tracking performance:
Sub-detector Design MCMDC σw (μm) 130 110
σp/p 0.5% 0.4%σdE/dx 6-7% 6%
TOF σt (ps) 90 85EMC σE/E 2.5% 2.2%
σxy(mm) 6 4.8MUC ε(μID) 95% 96%
ε(π->μ) 6% 6.2%
μ- at pt = 1GeV/cMomentum resolutionσ = 0.4 MeV
EMC (barrel) Energy Resolution -single γ
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Muon Counter
Ext track
Fired strips
Window
p(GeV/c)0 0.2 0.4 0.6 0.8 1 1.2
β
0.20.30.40.50.60.70.80.9
11.11.2
TOF
~1.2MeV
pπ→Λ
~3MeV−+→ ππKS
Physics Simulations
50, 000 ψ˝ Inclusiveevent sample.
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D0 to Kpi1.81 1.82 1.83 1.84 1.85 1.86 1.87 1.88
Eve
nts
/ ( 0
.000
8 )
0
200
400
600
800
1000
1200
1400
1600
1800
2000
2200
D0 to Kpi1.81 1.82 1.83 1.84 1.85 1.86 1.87 1.88
Eve
nts
/ ( 0
.000
8 )
0
200
400
600
800
1000
1200
1400
1600
1800
2000
2200
A RooPlot of "D0 to Kpi"
D0 to K3pi1.81 1.82 1.83 1.84 1.85 1.86 1.87 1.88
Eve
nts
/ (
0.00
08 )
0
50
100
150
200
250
300
350
400
450
D0 to K3pi1.81 1.82 1.83 1.84 1.85 1.86 1.87 1.88
Eve
nts
/ (
0.00
08 )
0
50
100
150
200
250
300
350
400
450
A RooPlot of "D0 to K3pi"
D0 to Kpipi01.81 1.82 1.83 1.84 1.85 1.86 1.87 1.88
Eve
nts
/ ( 0
.000
8 )
0
200
400
600
800
1000
1200
1400
1600
D0 to Kpipi01.81 1.82 1.83 1.84 1.85 1.86 1.87 1.88
Eve
nts
/ ( 0
.000
8 )
0
200
400
600
800
1000
1200
1400
1600
A RooPlot of "D0 to Kpipi0"
D0 to K0bpipi1.81 1.82 1.83 1.84 1.85 1.86 1.87 1.88
Eve
nts
/ ( 0
.000
8 )
0
50
100
150
200
250
300
350
400
D0 to K0bpipi1.81 1.82 1.83 1.84 1.85 1.86 1.87 1.88
Eve
nts
/ ( 0
.000
8 )
0
50
100
150
200
250
300
350
400
A RooPlot of "D0 to K0bpipi"
+−→ πKD0−++−→ πππKD0
+π
00 ππKD +−→−+→ ππKD S
0
50, 000 ψ˝ Inclusive event sample.
σ(mBC) ~ 1.2 MeV/c2
σ(ΔE) = 7 MeV
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BESIII: (8M , M.C.)m(χc1) = 3.508GeV,m(χc2) = 3.553GeV;σ(χc1) = 8.1MeV,σ(χc2) = 9.4MeV.
Ψ' γχcJ , χcJ γJ/ ψ
χc1 χc2
π0
η
Ψ' J/ψ(π0, η), (π0, η) γγ
χc0m(η) = 549 MeVm(π0) =135 MeV
m(χc-) =3.413GeV,σ(χc0) =9.0MeV.
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Physics Topics at BESIIIOpen charm factory :
• Absolute BR measurements of D and Ds decays• Rare D decay• D0 - D0bar mixing• CP violation• f D+, fDs form factors in semi-leptonic D decays• precise measurement (1.6% stat.) of CKM (Vcd, Vcs)• CP violation and strong phase in D Dalitz Decays• light meson spectroscopy in D0 and D+ Dalitz Decays.
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Physics Topics at BESIII
• Charmonium: J/ψ, ψ(2S), ηC(1S), χC{0,1,2} , ηC(2S), hC(1P1), ψ(1D), etc. • New Charmonium states above open charm threshold• Exotics : hybrids, glueballs, and other exotics in J/ψ and ψ(2S)
radiative decays.• Baryons and excited baryons in J/ψ and ψ(2S) hadronic decays.• Mesons and mixing of quark and gluon in J/ψ and ψ(2S) decays.• Electromagnetic form factors and QCD cross section (R values).• tau mass and tau physics near the threshold
Very rich and interesting energy region.
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Resonance Mass(GeV)CMS
Peak Lum.(1033cm-2s-1)
Physics Cross Section (nb)
Nevents/yr
J/ψ 3.097 0.6 3400 10 × 109
τ 3.670 1.0 2.4 12 × 106
DsDs 4.030 0.6 0.32 1.0 × 106
ψ(2S) 3.686 1.0 640 3.2 × 109
D0D0bar 3.770 1.0 3.6 18 × 106
D+D- 3.770 1.0 2.8 14 × 106
DsDs 4.140 0.6 0.67 2.0 × 106
Average Lum: L = 0.5×Peak Lum.; One year data taking time: T = 107s
Nevent/year = σexp ×L× T
Production
Huge J/ψ and ψ(2S) samples at BESIII
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BESIII CollaborationFirst formal meeting held Jan. 10-12, 2006 at IHEP, Beijing.Adopted Governance Rules, elected IB Chair and Spokespersons. Second collaboration meeting held June 11-13 at IHEP.Management plan adopted.
Institute of High Energy PhysicsUniversity of Science and TechnologyPeking UniversityTsinghua UniversityShangdong UniversityNankai UniversityCentral China Normal UniversityUniversity of AnhuiUniversity of ZhejiangUniversity of ZhengzhouNanjing Normal UniversityNanjing UniversityShanxi UniversitySichuan UniversityHenan Normal University
University of HawaiiUniversity of WashingtonUniversity of TokyoJoint Institute of Nuclear
Research, DubnaGSIUniversity of BochumUniversity of Giessen
Need more here!
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FutureIn US:• CLEOc stops in 2008• BaBar stops running in 2008.• Fermilab stops collider physics in 2009.
In China:BESIII commissioning in fall 2007.BESIII will be a unique facility.
☺
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Summary• BEPCII linac installation complete.• Installation of collider nearly complete;
synchrotron running fall 2006.• BESIII hardware and software progressing
rapidly, although still much to do.• Commissioning expected in fall 2007.• Rich physics program after CLEO-c.
Complementary to B-factories.• Collaborators welcomed!
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1.0 T1.0 T magnet
----9 layersμ counter
RichσT(ps) = 100-110/layer Double layer
TOF
2.0%0.3 cm /√E
Δ E/√E(0/0) = 2.5 %(1 GeV)σz(cm) = 0.5cm/√E
EMC
6%σdE/dx (0/0) = 6 - 7 %
0.5 %ΔP/P (0/0) = 0.5 %(1 GeV) MDC
90 μmσXY (μm) = 130
CLEOcBES IIIDetector
BESIII and CLEOc comparison