Vertex location status of Japan

1
Vertex location status of Japan
Nagoya vertex hunting team Y.Nonoyama, K.Hamada,
S.Takahashi, H.Kubota, R.Komatani 2009 Jan 22
OPERA Japan Meeting
2
Our history
Yoshiaki Nonoyama (Doctor course
student) Refresh (set up Temp and Humi monitor
system) PEANUT Kaname Hamada (Doctor course
student) Refresh Improve mechanical accuracy
of S-UTS stage Develop track reconstruction
soft-ware Satoru Takahashi (Doctor course
student) DONUT Refresh Gamma-ray telescope
with Emulsion Chamber Hirotaka Kubota (Doctor
course student) Refresh Fragmentation of
heavy-ion Gold deposition development Ryosuke
Komatani (Muster course student) Develop online
data process soft-ware
3
VTX location method
direct VTX hunting
scan back volume scan
scan back
volume scan around VTX prediction
point (1cm1cm10plates)
volume scan around stop plate (1cm1cm6plates)
not found
VTX search
partner parent search
found
VTX located
4
status table in Japan
re-glycerin, wait sheeting
21
waiting
scanning
40
28
CS
19
CS-gtECC
under analysis
42
14
ECC arrived
scan back
276
0
scanning
in progress
22.Dec. arrived
38
109
volume scan
61 (5.Jan. arrived)
62
under analysis
black CS
14
e-shower down plate single stop
5
VTX located
114
black ECC
finished
10
127
another brick
13
5
Vertex plate(CC,NC)
ALL
CC
NC
PL
down-stream
up-stream
6
Vertex plate(SB,DVH)
ALL
SB
DVH
PL
down-stream
up-stream
SB Scan Back Location DVH Direct Vertex
Hunting
7
Vertex position distribution(all plate)
Y(mm)
X(mm)
8
Number of shower tracks/interaction
ALL
CC
Mean 3.4 tracks
NC
N tracks
9
Angle distribution of shower tracks
qy
qx(rad)
10
Lock on decay search
Check track exist or not. (data and eyes) If stop
then look for parent or partner between 1mm of
lead
vertex point
vertex point
xz-projection
yz-projection
This is decay search sheet. Vertex plate and
down 23plate is most important plate(decay
trigger plate). These tracks are corrected by
less than IPlt200mm from vertex point. First we
check real stop then look for parent or 2nd
vertex. All young people rock on decay search.
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Summary

• We located 114 interactions out of 276 ECCs.
• Under analysis events for vertex confirm are
  stop down plate, e-shower and single stop.
• About stop down plate events, maybe scan-backed
  low-energy track.
• About e-shower events, it should be scan up
  plates.
• About single-stop events, it should be parent
  search and confirm real stop by eyes.
• We start decay search.
• A decay candidate is found. But very
  preliminary.
• This event stopped PL3, so now request
  down-stream ECC.
• Up to next meeting we can show final result
  about this event.

12
Back up
13
Event 235646940 Brick 41517 Type CC
Now request next brick
14
Under analysis events
Event 234787942 Brick 151760 Type CC
m
m
Maybe partner track make large angle. So it needs
large angle scanning (tanq 1 ).
15
Under analysis events e-shower
Event 234787942 Brick 151760 Type CC
16
Under analysis events e-shower
17
stop plate12
volume scan under analysis
2
single stop
14
7
e-shower
5