08/31/02PID Workshop@Nagoya1 TOP Counter R & D Status — PID and Physics — TOP Counter — R&D...
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08/31/02 PID Workshop@Nagoya 1 TOP Counter R & D Status — PID and Physics — TOP Counter — R&D Status Katsumi Senyo Nagoya University
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Transcript of 08/31/02PID Workshop@Nagoya1 TOP Counter R & D Status — PID and Physics — TOP Counter — R&D...
08/31/02 PID Workshop@Nagoya 1
TOP Counter R & D Status
— PID and Physics— TOP Counter— R&D Status
Katsumi SenyoNagoya University
08/31/02 PID Workshop@Nagoya 2
PID and Physics
B->DK/D
85.2±10.1
12.3±3.9
0.4±3.8
B->K/
Preliminary!
Preliminary!
08/31/02 PID Workshop@Nagoya 3
TOP Counter Performance(K/pi separation)
TOP ideal performance:Better than sig. 4
08/31/02 PID Workshop@Nagoya 4
PID and Physics
Current PID devices
TOP(expected perf.)
08/31/02 PID Workshop@Nagoya 5
Time Of Propagation(TOP) Counter
xz
y
20mm
PMTs Fused silica(n=1.47)
Reflection mirror 200mm
A few meters
08/31/02 PID Workshop@Nagoya 6
TOP Counter
MAPMT
Crystal Bar
1m
08/31/02 PID Workshop@Nagoya 7
PID Devices (3)
Cerenkov Counter
A charged particle velocity greater than the (local phase) velocity of light
→Radiating Cerenkov light
Cerenkov cone half angle:cos = 1/n
08/31/02 PID Workshop@Nagoya 8
DIRC(Detection of Internally Reflected Cherenkov light) and TOP Counter
DIRC: Radiation angle -> X-Y position
1m
TOP: Radiation angle -> Prop. Time-X position
Both TOP and DIRC give a hyperbolic projection image of Cherenkov light.
Time or
08/31/02 PID Workshop@Nagoya 9
TOP Counter
L y
zqzPMT
Radiation angle Propagation time
Short Propagation time: - likeLong Propagation time : K - like
08/31/02 PID Workshop@Nagoya 10
What’s problem in DIRC?
DIRC (cont.)
Huge Stand-off Volume
Is really such a dead volumeneeded?
~4m
08/31/02 PID Workshop@Nagoya 11
TOP Counter
The 3 dimension information of the Cerenkov cone is resolved with time and x position at the cross section of the fused silica. １
２
３
Readout
Propagation times of １ ,2,3 are different
08/31/02 PID Workshop@Nagoya 12
TOP Counter
TO
Px （ mm ）
TO
P
x （ mm ）
（ns
）
（ns
）
30 photons observed in typical case.
Unfolding
08/31/02 PID Workshop@Nagoya 13
Key Issues on TOP Counter R & D
Good timing resolution(~100ps) on a single photon measurement w/ position-sensitive(~1mm) MAPMT.
Precise fused silica bar production on geometry and smoothness (~ Å).
Sophisticated analysis method.
08/31/02 PID Workshop@Nagoya 14
MAPMT R & D
HPK R5900-U-L16 –Transit Time Spread~ ７５ ps–channel width １ mm
Collaboration w/ HPK
Insensitive region
08/31/02 PID Workshop@Nagoya 15
Fused Silica bar R & D
Δt ~150ps evenafter 4m transition
Improved Polish and Finish
Previous Polish
08/31/02 PID Workshop@Nagoya 16
Time v.s. X plot (Beam test result)
2.5GeV/c pion @KEK-PS pi2 line on Nov,2001.
Good relation of photon propagation time and X position at the edge is observed as expected.
Preliminary!
Preliminary!
200k events concentrated plot
08/31/02 PID Workshop@Nagoya 17
TOP Counter – Installed in Super-Belle
Υ （ 4s → ） BB
Installing Belle detector… r = 1m 30 < q < 140 barrel region
P(K/
)
08/31/02 PID Workshop@Nagoya 18
Bar TOP v.s. Mirror TOP(MC Study)
Separability > 4 in whole coverage of Super Belle
08/31/02 PID Workshop@Nagoya 19
Summary
TOP Counter is a promising PID device at next-generation B factories.
R & D is in good shape. Beam test results will be performed
on Nov.
08/31/02 PID Workshop@Nagoya 20
DIRC (cont.)
08/31/02 PID Workshop@Nagoya 21
PID and B Physics
Flavor Tagging
－ Determine a flavor of B
PK < 1.5 GeV/c Rare Decays including K and － B->K/DK/D 2.0 < PK < 4.0 GeV/c
08/31/02 PID Workshop@Nagoya 22
PID System at Belle
08/31/02 PID Workshop@Nagoya 23
DIRC Improvement
Focusing DIRC Photon Propagation Time
SLAC-PUB-8989 The Next Generation of Internally Reflected Imaging Counters, Sep.2001
n1
(a) Proximity
x~ x~
x~
x(pixel)
x(track) x(track) 2+x(pixel) 2
x(pixel)
x(pixel)
tx2+x(pixel) 2
12 2 12 2
x(pixel) 2
12 2
tx
tx
(c) Lens (d) Time
(b) Pinhole
Image Plane Detector
ngTrack
Track
Track
ngtanzz
(photon)
a
a
08/31/02 PID Workshop@Nagoya 24
TOP Counter (cont.)
–HPK R5900-U-L16 time res. ７５ ps channel width １ mm
30 photons observed in typical case
08/31/02 PID Workshop@Nagoya 25
TOP Counter(Bar width)2
c c c c
K K K K
50mm 100mm 150mm 200mm
The bar width should be 200 mm or larger in currentanalysis scheme.
08/31/02 PID Workshop@Nagoya 26
TOP Counter - Application
Detected #Photon : 30~100
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TOP Counter - Separability
S = 10 Mom. p = 4GeV/c, － 90° （ L = 2m ）
08/31/02 PID Workshop@Nagoya 28
Separability for B->
