Vertex location method

Vertex Location Reports from
Nagoya
Umut Kose
On the behalf of Nagoya Scanning Group
1
OPERA Collaboration Meeting 1-3 April 2009, Ankara/TURKEY
U. Kose
Vertex location method
CSD found
Black CS
direct VTX hunting method
scan back location method
scan back
volume scan
volume scan
around VTX prediction point
(~1cm*1cm*10plates)
around stop plate
(~1cm*1cm*6plates)
VTX search
not found
Scan around TT prediction
point (CC) 4cmx5cmx5plates
Finding the TT related
track, do scan back..
partner & parent search
found
VTX located
Volume Scan
around stop plate
(1cmx1cmx5plates)
Decay Search
OPERA Collaboration Meeting 1-3 April 2009, Ankara/TURKEY
2
U. Kose
From CS scanning results
1 track
Multi-tracks
Direct Vertex Hunting
37.8 %
62.2 %
Scan Back Location
ECC
CS
55%
45%
3
OPERA Collaboration Meeting 1-3 April 2009, Ankara/TURKEY
U. Kose
Summary of event location..
VTX located
Stopped in ECC
ScanBack
240
160
195
penetrating
16
ECC arrived
In progress
In progress
35
Edge out
4
18
415
In a few days
Failed
25
Failed
15 just arrived
19 thickness
48 CS rescan…
46
270
VTX located
65
Direct Vertex
121
In progress
10
225 events vertex confirmed (176 CC events + 49 NC events)
4
OPERA Collaboration Meeting 1-3 April 2009, Ankara/TURKEY
U. Kose
Edge event
23413110 10816 CC
0.015 0.115 64765.7
225199260 24729 CC
0.417 0.048
248.0
235009260 72466 CC
-0.154 0.063 122543.2
236878908 49041 CC
0.037 -0.113 53819.9
269.3
exit_pl_36 (22)
29490.0
exit_pl_12 (46)
16369.3
exit_pl_27 (31)
98595.7
exit_pl_46 (12)
5
OPERA Collaboration Meeting 1-3 April 2009, Ankara/TURKEY
U. Kose
# of events
Downstream

Upstream
12%
All events
CC events
NC events
# of plates
225 events vertex confirmed (176 CC events + 49 NC events)
6
OPERA Collaboration Meeting 1-3 April 2009, Ankara/TURKEY
U. Kose
# of events
Multiplicity distribution
7
OPERA Collaboration Meeting 1-3 April 2009, Ankara/TURKEY
U. Kose
Y(mm)
Vertex position distributions
X(mm)
8
OPERA Collaboration Meeting 1-3 April 2009, Ankara/TURKEY
U. Kose
Location of Black CS events..
Test done by Yoshida..
9
OPERA Collaboration Meeting 1-3 April 2009, Ankara/TURKEY
U. Kose
10
OPERA Collaboration Meeting 1-3 April 2009, Ankara/TURKEY
U. Kose
Strategy for Black CS events
Black CS
Scan around TT prediction
point (CC) 4cmx5cmx5plates
Finding the TT related
tracks, do scan back..
Volume Scan
around stop plate
(1cmx1cmx5plates)
Selection: at least 3 plate connections,
for CC use muon slope informations from TT
11
OPERA Collaboration Meeting 1-3 April 2009, Ankara/TURKEY
U. Kose
7 Bricks with black CS
4 CC events have been tried and 3 events have been confirmed…
230465150 13499 CC located
233284552 3657 CC failed
233334842 8282 CC located
234387666 3392 CC located
12
OPERA Collaboration Meeting 1-3 April 2009, Ankara/TURKEY
U. Kose
下から39枚目で別の飛跡を検出
下から39枚目で別の飛跡を検出
鉛中でμ候補と交わる（1.2micronまで接近する）
鉛中でμ候補と交わる（1.2micronまで接近する）
下流5枚のうち3枚以上で繋がった
下流5枚のうち3枚以上で繋がった
μ飛跡候補を追い上げる
μ飛跡候補を追い上げる
234387666
3392 CC
下から39枚目で別の飛跡を検出
鉛中でμ候補と交わる（1.2micronまで接近する）
下から39枚目までつながり、40枚目で無かった
下から39枚目までつながり、40枚目で無かった
下流5枚のうち3枚以上で繋がった
μ飛跡候補を追い上げる
下から39枚目までつながり、40枚目で無かった
230465150 13499 CC
Vertex plate at pl36
Scanback to find the stopping
plate
1st 5 plate data set
muon 2 real tracks found
14
Summary
-
Until now we have received 415 ECC
Vertex have been confirmed for 225 events (176 CC ; 49 NC)..
Test location analysis have been done for Black CS events, 4 CC
events tried and 3 of them located..
Decay search and detail analysis of the events is going on (see
Yoshioka`s talk)
15
OPERA Collaboration Meeting 1-3 April 2009, Ankara/TURKEY
U. Kose
16
Recieved CS 815
Scanned CS 718
Good candidate CS 476
Recieved ECC 415
VTX confirmed 225
18
Direct VTX hunting
•
•
•
•
Selected track is Rank-A or B.
Assumed momentum of each track is 1.5GeV/c.
Recognition of VTX is below 1sigma.
If muon is exist, VTX is searched below 3sigma.
19
Direct VTX Hunting Status
DVH Rank (A,B,C).
A
B
C
Good 
Delta-Plate : 1.5(A), 4.5(B)
A: 25% (58/229)  DVH
B: 23% (53/229)  SBL
C: 22% (51/229)  SBL
RMSdx,dy (A,B) ~ 1mm
Rank A
Rank B
20

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