LEPS experiment from 2008.Jan to 2009.Jul
using the new TPC and new liquid cryo-target system
• 2008.Jan-Jul: 257nm laser, LH2
2.96 GeV g
LH2
tagger rate ~2x105 /s

g + p Θ +K
+
*0
( K *  K )

~8x1011
*
(*) +
g
+
p

Λ
(
1405
)
+
K
photons
(~ old TPC run)
• 2008.Oct-Nov: 355nm laser, LD2 tagger rate ~1x106 /s
Speed up DAQ by decentralizing the TPC sense-wire readout
and modifying the program. Trigger: sideway + forward
2.4 GeV g
LD2

~1.6x1012
photons
g +" n"  Θ + + K 
Θ+  Ks + p   + +   + p
• 2008.Dec, 2009Feb,Jul: 355nm laser, LH2 : confirm the old TPC data,
•
calibration, etc.
~2.0x1012 photons
• 2009.Mar-Jul: 355nm laser, LHe : search for the Q+ hypernuclei
~4.6x1012 photons

g +4 He  (1520) + X
X : (Θ+ + d )bound
2008B-2009A：主な trouble & setting 変更
• 10/2: TPC FADC配線変更 （高速化）, プログラム修正
10/9-10/11: LD2, trigger#23(TPC) [DC2Uに歯抜け not for analysis]
• 10/11: DC2U PA交換、TagPL hrtdc用delay 一部変更
10/12-10/16: LD2, trigger#23
• 10/16: replace AC（1.0081.03), set ee-veto scinti add STD trigger
10/16-10/28, 11/13-11/29: LD2, trigger#24(TPC+STD)
11/17-12/7: LH2, trigger#24
• 12/7: DC1U trip [12/7-12/12: DC1U無しのデータ
not for analysis]
• 1月～2/4: DC1修理、TOF研磨、AC交換（2枚3枚）
• 2/4: setting&alignment(DC1,solenoid(TPC)+NDC,FWD,TOF)
2/7-2/8: LH2, trigger#24
• 2/8: Solenoid OFF [2/8-2/13 solenoid 磁場無しのデータ not for analysis]
• 2/13: solenoid temperature was recovered  solenoid ON
2/13-21: LH2, trigger#24
• 2/21: A wire of DC1V was broken (2/24,25 修理)
2008B-2009A：主な trouble & setting 変更
• 3/2: setting & alignment (DC1,solenoid(TPC)+NDC,FWD)
3/2-3/12: LHe, trigger#25(TPC/2+STD) [標的中に泡成長 not for analysis]
• 3/24,27: DC1再修理、レーザー系 第1、第2ミラー交換
4/6-4/22, 5/15-5/30, 6/1-6/17, 6/25-7/5: LHe, trigger STD
(5/15: set rate-monitor, 6/1: replace it to new one, 6/24: reset it)
7/7-7/24: LH2, trigger#24 (7/12: solenoid quench  recover soon)
7/25-7/26: 磁場無しラン (for software alignment)
7/26-28: Cu(test), trigger#24(narrow)
NB）10/15-10/28: AC1 は noisy
6/7-6/9: all DC gains were large due to incorrect gas mixture
6/28-30: peakADC of TPC anode#33 was strange
6/27-7/28: there might be a bad channel in the PADs of sector6, layer5
<Check scalers and singles histograms for all runs with modified online_ana>
Summary and corrected photon numbers of each run used for analysis:
http://www.rcnp.osaka-u.ac.jp/~yosoi/NTPC_Doc/index.html
Correction factor for Tagger scaler
• Calculate the correction factor according to Tech-note No.15
by Kohri (slightly modified)
Pile-up events: |T(i)-T(j)|< T_width ( best T_width=40nsec)
why?
Correction factor :
R=generated events/(generated events – pile-up events)
Correction factor for
each filling pattern
(revised on 2013 Feb.)
LHe run
TPC&STD/Tag (horizontal)
30
28
C-mode
D-mode
E-mode
M-mode
C-mode
D-mode
E-mode
A-mode
26
Ratio
24
22
20
18
16
14
41800
41900
42000
42100
corrected
42200
Run#
42300
42400
42500
42600
TPC&STD/corTag (horizontal)
30
28
26
Ratio
24
17.73±0.51
22
20
18
16
14
41800
41900
42000
42100
42200
Run#
42300
42400
42500
42600
C-mode
D-mode
E-mode
M-mode
C-mode
D-mode
E-mode
A-mode
LD2 run
TPC&STD/Tag (Horizontal)
36
34
32
Db-mode
A-mode
A-mode
Eb-mode
M-mode
Ratio
30
28
26
24
22
20
40500
40600
40700
40800
Run#
40900
41000
41100
TPC&STD/corTag (Horizontal)
corrected
36
34
32
25.15±0.38
Ratio
30
Db-mode
A-mode
A-mode
Eb-mode
M-mode
28
26
24
22
20
40500
40600
40700
40800
Run#
40900
41000
41100
LH2 run
TPC&STD/Tag (Horizontal)
TPC&STD/Tag (Horizontal)
20
18
18
16
16
M-mode
Db-mode
Db-mode
C-mode
M-mode
A-mode
M-mode
C-mode
Da-mode
Ratio
Ratio
20
14
14
12
12
10
41000
41100
41200
41300
41400
41500
10
42500
41600
42600
Run#
TPC&STD/corTag (Horizontal)
20
18
18
16
16
Ratio
Ratio
20
14
12
12
41200
41300
Run#
41400
41500
41600
M-mode
Db-mode
Db-mode
C-mode
M-mode
A-mode
M-mode
C-mode
Da-mode
13.16±0.25
14
41100
42800
Run#
corrected TPC&STD/corTag (Horizontal)
10
41000
42700
10
42500
42600
42700
Run#
42800
Data statistics
• Corrected tagger photon# ×DAQ live ratio
LHe(Std):
4.55x1012 (hori 2.25x1012, vert 2.30x1012)
LD2(#24/#23): 1.64x1012 (hori 0.82x1012, vert 0.82x1012)
[trig#24 1.41x1012/ trig#23 0.23x1012]
LH2(#24):
1.96x1012 (hori 0.93x1012, vert 1.03x1012)
• Luminosity (L=nb・NT NT =rNA/A )
Scaling factor of transmission: 0.525±0.013 (from PWO data)
Target density of LHe/LD2/LH2 with 15cm at boiling point
1.875 g/cm2, 2.535 g/cm2, 1.062 g/cm2
Luminosity: LHe 6.79x1035 cm-2 =0.679 pb-1
LD2 6.53x1035 cm-2 =0.653 pb-1
LH2 6.53x1035 cm-2 =0.653 pb-1
cf.) 3GeV LH2 (～0.8x1012x0.532)x(1.062xNA/A) = 0.27 pb-1
pedestal_mean
Check pedestal files (miho:/np1b/v04/sp8lep/ntpc/pede/)
Run#
・ remove some strange runs
(not junk runs in the log-note)
・ ch1253 (Preamp79, ch 5) shows
2 lines.
(sector 6, layer 7, 3rd pad)
NTPC gain correction
with cosmic-ray data
wire gain (r40210)
110
100
cut: |dip angle|<15°
-1717<z<-1517
peak channel
90
80
cut-fix
nocut-fix
70
60
50
40
0
10
20
30
40
50
60
anode #
gain
読んでいない両端のWire は
1番目と27番目のwire の x0.5
が良い
170
160
150
peak channel
Pad (peakAdc) vs wire sum
 good
S wihi /S wi
w-2=w2=0.127516
w-1=w1=0.245298
w0=0.298944
140
pad
wire sum
wire sum0
130
120
110
100
90
80
0
5
10
layer#(U:1-9,D:10-18)
15
20
z-dependence of Pad gain
(-25<x<25)
y
y
(-1717<z<-1517)
z
x
z-dependence of Pad gain (Gauss fit)
1.3
1.25
1.2
ratio for z=-1617
1.15
1.1
1.05
1
0.95
0.9
0.85
-1900
-1800
-1700
-1600
-1500
z (mm)
-1400
-1300
0.8
-1200
-1100
U-ave
D-ave
Sum

Celia Oreja-Guevara - European Medicines Agency

Publications Malcolm Kohler