Post on 10-Jul-2020
Status of E14/KOTO T. Nomura (KEK)
1
•Intro•Run summary•Analysis status•Preparation for next run
KOTO intro
• KOTO aims to observe KL→π0νν• CP violating process• FCNC; occurs via loop diagrams• Branching ratio is well calculated by SM
with small uncertainty (~2%)
• Good mode to search BSM contribution
• Current experimental situation• Direct limit: Br<2.6×10-8 (90%CL)
• by KEK-E391a (predecessor of KOTO)
• Grossman-Nir limit: Br<1.5×10-9 • Limit from measured Br(K+→π+νν) by BNL-787/949
2
1140.037.0 10)06.043.2( −+
− ×±=SMBRIntrinsic uncertainty
KOTO detector
3
OK T�
�s
d
KAON13 @ Univ. of Michigan Ann Arbor
Principle• KL pencil beam• 2γ + nothing
• Calorimeter + Hermetic veto
3
FB NCC MB CVCsI calorimeter
CC03OEV
CC04 CC05 CC06 BHCV BHPV
LCVBCVHINEMOS
Saturday, April 20, 2013
10m
Vacuum chamber
KL
Decay region
primary p(30GeV)
target
!, n
20m beam lineSweeping magnet and collimator
KL
Hermetic veto Calorimeter
Charged
!
!
"
"
"
"
!!
!"#$%&$ '
!"##$%&'()*+,*-(&%
.(&%*/0"1$#(*&1'(0*2"##$%&'"0*&#$34%(4'*5*6+
7"8(&-#(*'9"*:'&3(*2"##$%&'"0!"#$%&'()*+*#,(-#.%/#012345#678#9:!:#
;(<<*=(-*.&(>?#@AB#3#CDE#FDG7GH#IJI
K"#!*L*%*M%&#/.#*<"?#0N>"#0"#3NN<"#2%OM"#IG#FDG77H#GECPG7
T. Shimogawa et al., NIMA 623, (2010) 585
OK T�
�s
d
KAON13 @ Univ. of Michigan Ann Arbor
Principle• KL pencil beam • 2γ + nothing
• Calorimeter + Hermetic veto
• Signal reconstruction• Assume 2 gammas come from π0
• Require large transverse momentum• z vertex - Pt distribution
4
2.3 バックグラウンド 11
という関係が得られる。E1、E2 は入射 ! のエネルギーである。Eqs.(2.3-2.6)を用いると、"0 の崩壊位置 Zvtx が求まる。得られた Zvtx を使うと 2つの ! の運動量ベクトルを得ることができ、その和が "0 の運動量ベクトルになる。したがって "0 のビーム軸に垂直な運動量成分 Pt も求めることが出来る。この 2つのパラメータ Zvtx と Pt をシグナルとバックグラウンドの識別に利用する。この部分については参考文献 [21]に詳しく記述されている。またこの 2つのパラメータ平面上でシグナルイベントは Fig.2.3のように分布する。図の赤枠で囲まれる部分を signal boxと呼ぶ。
Fig. 2.2 K0L ! !0"" からの !0 の再構成。
1
10
210
Z Vertex
10001500200025003000350040004500500055006000
tP
0
50
100
150
200
250
300
350
400
pi0nunu/pi0nunu/pi0nunuann08_100.rootpi0nunu/pi0nunu/pi0nunuann08_100.root
1
10
210
Z Vertex
10001500200025003000350040004500500055006000
tP
0
50
100
150
200
250
300
350
400
pi0nunu/pi0nunu/pi0nunuann00_100.rootpi0nunu/pi0nunu/pi0nunuann00_100.root
1
10
210
Z Vertex
10001500200025003000350040004500500055006000
tP
0
50
100
150
200
250
300
350
400
pi0nunu/pi0nunu/pi0nunuann05_100.rootpi0nunu/pi0nunu/pi0nunuann05_100.root
1
10
210
Z Vertex
10001500200025003000350040004500500055006000
tP
0
50
100
150
200
250
300
350
400
pi0nunu/pi0nunu/pi0nunuann08_100.rootpi0nunu/pi0nunu/pi0nunuann08_100.root
-110
1
10
210
Z Vertex
10001500200025003000350040004500500055006000
tP
0
50
100
150
200
250
300
350
400
pi0nunu/pi0nunu/pi0nunuann00_100.rootpi0nunu/pi0nunu/pi0nunuann00_100.root
-110
1
10
Z Vertex
10001500200025003000350040004500500055006000
tP
0
50
100
150
200
250
300
350
400
pi0nunu/pi0nunu/pi0nunuann05_100.rootpi0nunu/pi0nunu/pi0nunuann05_100.root
[MeV/c]
[mm]
Fig. 2.3 K0L ! !0"" 分布。赤枠で囲ま
れた部分を信号事象と同定する。横軸の 0は Front Barrel( 2.6.1)の上流端。
2.3 バックグラウンドKOTO実験のバックグラウンド事象 (以下 B.G.)は次の2つに分類することが出来る。1つは K0
L 自身が B.G.の源となるものである。代表的な例としては、K0L ! 2"0 の崩壊で生成
された4つの ! のうち 2 つを検出できなかった (miss veto) 場合が挙げられる。もう1つはビームコア周りに存在するハロー中性子が源となるものである。この場合,ハロー中性子は検出器中の物質と相互作用し、"0 を生成し、その信号をシグナルと見誤る事に起因する。ここではこれらのB.G.について簡単にまとめる。
2.3.1 K中間子 B.G.
Table2.1に K0L の主な崩壊モードと分岐比をまとめておく。これらは K中間子 B.G.の元にな
り得る。以下、各モードについて簡単にまとめておく。
cos � = 1�M2
⇡0
2E1E2
1
10
210
Z Vertex
10001500200025003000350040004500500055006000
tP
0
50
100
150
200
250
300
350
400
pi0nunu/pi0nunu/pi0nunuann08_100.rootpi0nunu/pi0nunu/pi0nunuann08_100.root
1
10
210
Z Vertex
10001500200025003000350040004500500055006000
tP
0
50
100
150
200
250
300
350
400
pi0nunu/pi0nunu/pi0nunuann00_100.rootpi0nunu/pi0nunu/pi0nunuann00_100.root
1
10
210
Z Vertex
10001500200025003000350040004500500055006000
tP
0
50
100
150
200
250
300
350
400
pi0nunu/pi0nunu/pi0nunuann05_100.rootpi0nunu/pi0nunu/pi0nunuann05_100.root
1
10
210
Z Vertex
10001500200025003000350040004500500055006000
tP
0
50
100
150
200
250
300
350
400
pi0nunu/pi0nunu/pi0nunuann08_100.rootpi0nunu/pi0nunu/pi0nunuann08_100.root
-110
1
10
210
Z Vertex
10001500200025003000350040004500500055006000
tP
0
50
100
150
200
250
300
350
400
pi0nunu/pi0nunu/pi0nunuann00_100.rootpi0nunu/pi0nunu/pi0nunuann00_100.root
-110
1
10
Z Vertex
10001500200025003000350040004500500055006000
tP
0
50
100
150
200
250
300
350
400
pi0nunu/pi0nunu/pi0nunuann05_100.rootpi0nunu/pi0nunu/pi0nunuann05_100.root
[MeV/c]
[mm]
Rec
onst
ruct
ed P
t [M
eV/c
]
Reconstructed vertex [mm] 1000 3500 6000
KL ! ⇥0��̄ signal box
!0
FB NCC MB CVCsI calorimeter
CC03OEV
CC04 CC05 CC06 BHCV BHPV
LCVBCVHINEMOS
Saturday, April 20, 2013
10m
Vacuum chamber
KL
Decay region
"
"
!!
1
10
100
0.1
50
100
150
200
250
300
350
450
A narrow KL beam is the key.
• Signature of KL→π0νν = 2γ + nothing• EM calorimeter + hermetic veto
• Reconstruct kinematics• decay vertex (Z), π0 PT
4
OK T�
�s
d
KAON13 @ Univ. of Michigan Ann Arbor
Principle• KL pencil beam• 2γ + nothing
• Calorimeter + Hermetic veto
3
FB NCC MB CVCsI calorimeter
CC03OEV
CC04 CC05 CC06 BHCV BHPV
LCVBCVHINEMOS
Saturday, April 20, 2013
10m
Vacuum chamber
KL
Decay region
primary p(30GeV)
target
!, n
20m beam lineSweeping magnet and collimator
KL
Hermetic veto Calorimeter
Charged
!
!
"
"
"
"
!!
!"#$%&$ '
!"##$%&'()*+,*-(&%
.(&%*/0"1$#(*&1'(0*2"##$%&'"0*&#$34%(4'*5*6+
7"8(&-#(*'9"*:'&3(*2"##$%&'"0!"#$%&'()*+*#,(-#.%/#012345#678#9:!:#
;(<<*=(-*.&(>?#@AB#3#CDE#FDG7GH#IJI
K"#!*L*%*M%&#/.#*<"?#0N>"#0"#3NN<"#2%OM"#IG#FDG77H#GECPG7
T. Shimogawa et al., NIMA 623, (2010) 585
Front Barrel
Main Barrel Charged Veto
CsI calorimeterNeutron Collar
Counter
Vacuum Tank
KOTO DAQ flow
5
• Record waveforms from all channels with ADCs• Raw signal ➟ 10-pole gaussian filter ➟ 14-bit 125MHz ADC• 12-bit 500MSPS ADC for in-beam detectors
• Digitized signal information is used in the trigger system• Level 1: Energy sum, number of hits in each sub-detector• Level 2: Center of energy (COE) in the calorimeter
Trigger Rate And Data Transfer Rate
19
Flash ADC Lv2 Triggersystem
Event Building,
Lv3 trigger
DataStore
Level 1 Trigger
Data Data Data
<100kEvents/Spill <8kEvents/Spill Output Rate<2Gbps
Level 2 Trigger Level 3 Trigger
AnalogSignal
Lv1 trigger Lv2 trigger(Lv3 trigger,)Compression
30kEvents/Spill
30kEvents/Spill
~7kEvents/Spill
Input:6Gbps
Output:2Gbps
Input
OutputLimit
Data Data
192013年7月24日水曜日
KEKCC(Tsukuba)
Original run plan
6
Dec.2012 ~ 2013Engineering run in air (>8 days)
>1 week for evacuation
Engineering run in vacuum (>6 days)
>1 month for fixing potential problems
Short physics run (12 days)
>1 month for analysis and repairs
Long physics run (450 kW x days + 5days) to cross the Grossman-Nir Limit
= 30days@15kW + 5days
28
Dec
Mar
May
Jan
✔
✔
Presented at previous PAC meeting in January 2013
Actual beam time
• 2012 December : Engineering run in Air• 11kW 8.5days
• 2013 January : Engineering run in vacuum• 11kW 1.5days +15kW 6.5days
• 2013 March : Tuning for physics run• 15kW 3.5days• Terminated due to trouble in SX septum magnet
• 2013 April : Tuning for physics run• 15kW 1.5days
• 2013 May : Physics run• 15kW 1.5days + 20kW 1day + 24kW 4days• Terminated due to the accident in Hadron Hall
7
✔
✔
Completed detectors in vacuum tank
Installed downstream detectors
POT in May physics run
8
Date 18/05 19/05 20/05 21/05 22/05 23/05
16 10×
Inte
grat
ed N
of P
.O.T
.
020406080
100120140160
Integrated N of P.O.T
Date 18/05 19/05 20/05 21/05 22/05 23/05
Inte
grat
ed ti
me (
hour
s)
0
20
40
60
80
100
Integrated time
Date 19/05 26/05 02/06 09/06 16/06 23/06
16 10×
Inte
grat
ed N
of P
.O.T
.
100200300400500600700800900
1000Integrated N of P.O.T 24kW20kW
SX study
maintenance
1.6×1018 POT accumulatedfor physics run
~1/5 of original goal in May-June run
Data types
• Physics: CsI total E && no hit in veto && large COE (Lv2)• KL→π0νν
• Normalization: CsI total E && no hit in veto (PreScaled=1/30)
• KL→3π0, 2π0, 2γ• Minimum bias: CsI total E (PS=1/300)
• Calibration• KL→3π0: CsI total E && CsI hit region>4 && no hit in veto (PS=1/10)
• Cosmic ray (in off-spill)• Laser, LED• [Special run] Muon-enhanced run (with beam plug being closed)
• Accidental (random trigger)• TMON (target monitor provided by HD beam line G) (PS=1/1200)
• Clock
9
Trigger rate: Level1 28k/spill ( 27k for physics)Level2 7.4k/spill (5.2k for physics)
Misc performance during physics run
• Missing channels• 2 in calorimeter (among 2716 channels)• 2 in charged veto (among 184 channels)
• One of both-end readout; the modules were treated as single-end readout.
• 1 in CC03 (among 32 channels)• One crystal read by two PMTs; the output of the crystal got a half.
• All other channels were alive.
• Vacuum level• ~5×10-5 Pa in high vacuum region (decay region)• ~0.1 Pa in low vacuum region (detector region)
• Data transfer to KEK Computing Center• 2.7 Gbps constantly achieved (> data accumulating speed)
10
Analysis status
• January data• Intensive analysis of normalization modes
KL→3π0, KL→2π0, KL→2γ
• May data• Checked quality of data• Mostly finished calibration (energy, timing)• Started analysis of normalization modes• Veto performances under study
11
From January run
Calorimeter calibration 1 - cosmic ray
• E calibration before beam run using cosmic ray• Initial calibration• Also used for gain adjustment
of each crystal(to use in trigger)
• E calibrations of other detectors were also done with cosmic ray data.(Except for detectors that are only sensitive to particles in the beam direction.)
12
OK T�
�s
d
日本物理学会 2013年秋季大会 21aSL01
Calibration• CsI の energy calibration は3種の方法を併用• Cosmic ray calibration• 宇宙線による initial energy calibration• KL→3π0 calibration• 結晶間の relative calibration
• 6γ event に対し、KL→3π0由来と仮定する事で、結晶毎に校正値の微調整を行う• Al target calibration• Absolute calibration
• ビーム中にAl (5mm thick)を挿入し、π0 を生成する。Vertex, π0 mass を拘束条件とし、校正値の絶対値を決定
8
-800 -600 -400 -200 0 200 400 600 800
-800
-600
-400
-200
0
200
400
600
800
Run14200 Event33320
10
15
20
25
30
Run14200 Event33320 energy [MeV]
n π0 π0
γ
γ
Al plate
Cosmic ray event display
downEntries 101061Mean 3.113± 4411 RMS 2.201± 948.7 Underflow 688Overflow 36Integral 9.286e+04
/ ndf 2! 55.24 / 37p0 32.2± 2499 p1 0.6± 5301 p2 0.69± 48.13 p3 16.3± 726.5 p4 7.8± 5240 p5 4.3± 241.5 vertex z position0"Reconstructed
2000 2500 3000 3500 4000 4500 5000 5500 6000
# of
eve
nts/3
0 m
m
0
500
1000
1500
2000
2500
3000
downEntries 101061Mean 3.113± 4411 RMS 2.201± 948.7 Underflow 688Overflow 36Integral 9.286e+04
/ ndf 2! 55.24 / 37p0 32.2± 2499 p1 0.6± 5301 p2 0.69± 48.13 p3 16.3± 726.5 p4 7.8± 5240 p5 4.3± 241.5
Al target run (Run13531-13658) upEntries 95809Mean 2.88± 3927 RMS 2.036± 852.8 Underflow 1236Overflow 4Integral 8.769e+04
/ ndf 2! 95.49 / 64p0 16.7± 1438 p1 1.0± 3150 p2 0.99± 90.86 p3 1093.3± 3965 p4 680.0± 9387 p5 159.1± 2740
upEntries 95809Mean 2.88± 3927 RMS 2.036± 852.8 Underflow 1236Overflow 4Integral 8.769e+04
/ ndf 2! 95.49 / 64p0 16.7± 1438 p1 1.0± 3150 p2 0.99± 90.86 p3 1093.3± 3965 p4 680.0± 9387 p5 159.1± 2740
KL
Rec. π0 vertex [mm]
From January run
Calorimeter calibration 2 - Al target
• 5mm Al target inserted in the neutral beam• π0 production at known z position
• Absolute energy scale can be obtained.(If π0 mass is assumed, a peak can be observed at corresponding z position.)
13
Upstream Al target(removable; driven by a motor)
OK T�
�s
d
日本物理学会 2013年秋季大会 21aSL01
Calibration• CsI の energy calibration は3種の方法を併用• Cosmic ray calibration• 宇宙線による initial energy calibration• KL→3π0 calibration• 結晶間の relative calibration
• 6γ event に対し、KL→3π0由来と仮定する事で、結晶毎に校正値の微調整を行う• Al target calibration• Absolute calibration
• ビーム中にAl (5mm thick)を挿入し、π0 を生成する。Vertex, π0 mass を拘束条件とし、校正値の絶対値を決定
8
-800 -600 -400 -200 0 200 400 600 800
-800
-600
-400
-200
0
200
400
600
800
Run14200 Event33320
10
15
20
25
30
Run14200 Event33320 energy [MeV]
n π0 π0
γ
γ
Al plate
Cosmic ray event display
downEntries 101061Mean 3.113± 4411 RMS 2.201± 948.7 Underflow 688Overflow 36Integral 9.286e+04
/ ndf 2! 55.24 / 37p0 32.2± 2499 p1 0.6± 5301 p2 0.69± 48.13 p3 16.3± 726.5 p4 7.8± 5240 p5 4.3± 241.5 vertex z position0"Reconstructed
2000 2500 3000 3500 4000 4500 5000 5500 6000
# of
eve
nts/3
0 m
m
0
500
1000
1500
2000
2500
3000
downEntries 101061Mean 3.113± 4411 RMS 2.201± 948.7 Underflow 688Overflow 36Integral 9.286e+04
/ ndf 2! 55.24 / 37p0 32.2± 2499 p1 0.6± 5301 p2 0.69± 48.13 p3 16.3± 726.5 p4 7.8± 5240 p5 4.3± 241.5
Al target run (Run13531-13658) upEntries 95809Mean 2.88± 3927 RMS 2.036± 852.8 Underflow 1236Overflow 4Integral 8.769e+04
/ ndf 2! 95.49 / 64p0 16.7± 1438 p1 1.0± 3150 p2 0.99± 90.86 p3 1093.3± 3965 p4 680.0± 9387 p5 159.1± 2740
upEntries 95809Mean 2.88± 3927 RMS 2.036± 852.8 Underflow 1236Overflow 4Integral 8.769e+04
/ ndf 2! 95.49 / 64p0 16.7± 1438 p1 1.0± 3150 p2 0.99± 90.86 p3 1093.3± 3965 p4 680.0± 9387 p5 159.1± 2740
KL
Rec. π0 vertex [mm]
Preliminary
From January run
Calorimeter calibration 3 - KL→3π0
• Relative calibration using 6γ from KL→3π0
• Constraint fitting with 4 parameters and 6 constraints
OK T�
�s
d
日本物理学会 2013年秋季大会 21aSL01
3π0 calibration• KL→3π0 を用いて、結晶間の相対補正が可能• 6cluster event は KL→3π0→6γ 由来と仮定• invariant mass が π0, KL になるようγのエネルギーを補正• Ei → Ei’
• KL→3π0 event を集め、各結晶毎に補正値分布の中心値を採用
• iterationを行い、校正精度を上げる
17
E0E1
E2
E3
E4E5
(vx, vy, vz)
6 constraints(E0 + E1)
2 � ( �P0 + �P1)2 = M�0
2
(E2 + E3)2 � ( �P2 + �P3)
2 = M�02
(E4 + E5)2 � ( �P4 + �P5)
2 = M�02
5X
i=0
Ei
!2
�
5X
i=0
Pi
!2
= MKL
2
5X
i=0
xi · Ei = vx ·5X
i=0
Ei
5X
i=0
yi · Ei = vy ·5X
i=0
Ei
his_KL_mass_UseEntries 1571828
Mean 6.581± 498.2
RMS 4.653± 5.985
Underflow 0.0001882
Overflow 0.1286
Integral 0.8273
]2 invariant mass [MeV/c!6480 485 490 495 500 505 510 515 520
[a.u
.]2
# of
eve
nts
/ 0.5
MeV
/c
0
0.005
0.01
0.015
0.02
0.025
0.03
0.035
0.04
0.045
his_KL_mass_UseEntries 1571828
Mean 6.581± 498.2
RMS 4.653± 5.985
Underflow 0.0001882
Overflow 0.1286
Integral 0.8273
calibration0"3
4 parameters(v
x
, vy
, vz
)
E0i
/Ei
Iteration 0Iteration1Iteration 9
Normalized by area
OK T�
�s
d
日本物理学会 2013年秋季大会 21aSL01
3π0 calibration• KL→3π0 を用いて、結晶間の相対補正が可能• 6cluster event は KL→3π0→6γ 由来と仮定• invariant mass が π0, KL になるようγのエネルギーを補正• Ei → Ei’
• KL→3π0 event を集め、各結晶毎に補正値分布の中心値を採用
• iterationを行い、校正精度を上げる
17
E0E1
E2
E3
E4E5
(vx, vy, vz)
6 constraints(E0 + E1)
2 � ( �P0 + �P1)2 = M�0
2
(E2 + E3)2 � ( �P2 + �P3)
2 = M�02
(E4 + E5)2 � ( �P4 + �P5)
2 = M�02
5X
i=0
Ei
!2
�
5X
i=0
Pi
!2
= MKL
2
5X
i=0
xi · Ei = vx ·5X
i=0
Ei
5X
i=0
yi · Ei = vy ·5X
i=0
Ei
his_KL_mass_UseEntries 1571828
Mean 6.581± 498.2
RMS 4.653± 5.985
Underflow 0.0001882
Overflow 0.1286
Integral 0.8273
]2 invariant mass [MeV/c!6480 485 490 495 500 505 510 515 520
[a.u
.]2
# of
eve
nts
/ 0.5
MeV
/c
0
0.005
0.01
0.015
0.02
0.025
0.03
0.035
0.04
0.045
his_KL_mass_UseEntries 1571828
Mean 6.581± 498.2
RMS 4.653± 5.985
Underflow 0.0001882
Overflow 0.1286
Integral 0.8273
calibration0"3
4 parameters(v
x
, vy
, vz
)
E0i
/Ei
Iteration 0Iteration1Iteration 9
Normalized by area
OK T�
�s
d
日本物理学会 2013年秋季大会 21aSL01
3π0 calibration• KL→3π0 を用いて、結晶間の相対補正が可能• 6cluster event は KL→3π0→6γ 由来と仮定• invariant mass が π0, KL になるようγのエネルギーを補正• Ei → Ei’
• KL→3π0 event を集め、各結晶毎に補正値分布の中心値を採用
• iterationを行い、校正精度を上げる
17
E0E1
E2
E3
E4E5
(vx, vy, vz)
6 constraints(E0 + E1)
2 � ( �P0 + �P1)2 = M�0
2
(E2 + E3)2 � ( �P2 + �P3)
2 = M�02
(E4 + E5)2 � ( �P4 + �P5)
2 = M�02
5X
i=0
Ei
!2
�
5X
i=0
Pi
!2
= MKL
2
5X
i=0
xi · Ei = vx ·5X
i=0
Ei
5X
i=0
yi · Ei = vy ·5X
i=0
Ei
his_KL_mass_UseEntries 1571828
Mean 6.581± 498.2
RMS 4.653± 5.985
Underflow 0.0001882
Overflow 0.1286
Integral 0.8273
]2 invariant mass [MeV/c!6480 485 490 495 500 505 510 515 520
[a.u
.]2
# of
eve
nts
/ 0.5
MeV
/c
0
0.005
0.01
0.015
0.02
0.025
0.03
0.035
0.04
0.045
his_KL_mass_UseEntries 1571828
Mean 6.581± 498.2
RMS 4.653± 5.985
Underflow 0.0001882
Overflow 0.1286
Integral 0.8273
calibration0"3
4 parameters(v
x
, vy
, vz
)
E0i
/Ei
Iteration 0Iteration1Iteration 9
Normalized by area
parameters:•decay vertex: vx,vy,vz
•E of i-th photon constraints:• mass of 3 pairs = Mπ0
• mass of 6γ = MKL
• vertex x,y correlate with COE
14
Calibrationusing KL→3π0
Improvements in simulation- reflection of the real world -
• Considered energy fluctuation due to photo-electron statistics
• Implemented fluctuation due to electronic noise• Though it is small (<0.5MeV equiv. per each channel)
• Overlaid accidental activities• using TMON data
• ...
15
From January run
Normalization modes
16
OK T�
�s
d
日本物理学会 2013年秋季大会 21aSL01
p [MeV/c]0 1000 2000 3000 4000 5000 6000 7000
# of
eve
nts /
100
MeV
1
10
210
310
hKlongMom3pi0Entries 426305Mean 1.266± 2255 RMS 0.8954± 826.8 Underflow 0Overflow 0Integral 7.89e+04
Data
MC0!3"LK
momemtumLRec. K
hRatioEntries 247Mean 117.9± 3860 RMS 83.33± 1853 Underflow 0Overflow 0Integral 63.91
momentum [MeV/c]Lrec. K0 1000 2000 3000 4000 5000 6000 7000
Rat
io (D
ata/
MC
)
00.20.40.60.8
11.21.41.61.8
2 hRatioEntries 247Mean 117.9± 3860 RMS 83.33± 1853 Underflow 0Overflow 0Integral 63.91
• Mass, Momentum ともに再現できている
KL→3π0 11
ener
gy (l
og) [
MeV
]
0.5
1
1.5
2
2.5
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI energy ( > 3MeV )CSI energy ( > 3MeV )
ener
gy (l
og) [
MeV
]
0.5
1
1.5
2
2.5
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI energy in clusterCSI energy in clusterRun 13710
Node 000
DstEntry 00089
nGammas 6
MyCutCondition 0
MyVetoCondition 0
KL mass 491.839923
ExtraClusterDeltaTime 0.000000
time
[ns]
150
160
170
180
190
200
210
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI time ( > 3MeV )CSI time ( > 3MeV )
time
[mm
]
202
204
206
208
210
212
214
216
218
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI time in clustersCSI time in clusters
time
[mm
]
202
204
206
208
210
212
214
216
218
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI time in gammasCSI time in gammas
]2mass [MeV/c400 420 440 460 480 500 520 540 560 580 600
2#
of ev
ents
/ 2
MeV
/c
1
10
210
310
410
hKlongMass3pi0Entries 456640Mean 0.01634± 498.2 RMS 0.01155± 10.97 Underflow 0Overflow 1136Integral 8.338e+04
Data
MC0!3"LK
massLRec. K
hRatioEntries 2735Mean 1.068± 505.9 RMS 0.7548± 55.83 Underflow 0Overflow 1.113Integral 98.94
]2 invariant mass [MeV/c#6400 420 440 460 480 500 520 540 560 580 600
Rat
io (D
ata/
MC
)
00.20.40.60.8
11.21.41.61.8
2 hRatioEntries 2735Mean 1.068± 505.9 RMS 0.7548± 55.83 Underflow 0Overflow 1.113Integral 98.94
Accept
Δ vertex time < 3ns
Δ KL mass < 15 MeV/c2
Min. halfEt > 350 MeV
KL pt < 50 MeV/c
KL χz2 < 20
Δπ0 mass < 10 MeV/c2
Δπ0 z < 400 mm
Min. GammaE > 50 MeV
Min. Fiducial XY > 120 mm
Max. Fiducial R < 850 mm
Min. Cluster dist. > 150 mm
KL z 2000 -- 5400 mm
Preliminary Preliminary
KL→3π0 event display
Rec. mass distribution Rec. momentum distribution
OK T�
�s
d
日本物理学会 2013年秋季大会 21aSL01
0 1000 2000 3000 4000 5000 6000
# of
even
ts /
100
MeV
20
40
60
80
100
120 Data MC0!2"LK MC0!3"LK
MC0!-!+!"LK
momemtumLRec. K
hRatioEntries 102Mean 159± 3382 RMS 112.5± 1609 Underflow 0Overflow 0Integral 57.07
momentum [MeV/c]0 1000 2000 3000 4000 5000 6000
Rat
io (D
ata/
MC
)
00.20.40.60.8
11.21.41.61.8
2 hRatioEntries 102Mean 159± 3382 RMS 112.5± 1609 Underflow 0Overflow 0Integral 57.07
250 300 350 400 450 500 550 600
2#
of ev
ents
/ 4
MeV
/c
100
200
300
400
500
600
700 Data MC0!2"LK MC0!3"LK
MC0!-!+!"LK
massLRec. K
hRatioEntries 2882Mean 1.765± 433.2 RMS 1.248± 94.78 Underflow 0Overflow 1.06Integral 81.91
]2 invariant mass [MeV/c#4250 300 350 400 450 500 550 600
Rat
io (D
ata/
MC
)
00.20.40.60.8
11.21.41.61.8
2 hRatioEntries 2882Mean 1.765± 433.2 RMS 1.248± 94.78 Underflow 0Overflow 1.06Integral 81.91
ener
gy (l
og) [
MeV
]
0.5
1
1.5
2
2.5
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI energy ( > 3MeV )CSI energy ( > 3MeV )
ener
gy (l
og) [
MeV
]
0.5
1
1.5
2
2.5
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI energy in clusterCSI energy in clusterRun 13669
Node 000
DstEntry 00081
nGammas 4
MyCutCondition 0
MyVetoCondition 0
KL mass 501.087490
ExtraClusterDeltaTime 0.000000
time
[ns]
100
150
200
250
300
350
400
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI time ( > 3MeV )CSI time ( > 3MeV )
time
[mm
]
198
200
202
204
206
208
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI time in clustersCSI time in clusters
time
[mm
]
198
200
202
204
206
208
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI time in gammasCSI time in gammas
• こちらもMass, Momentum ともに再現している
KL→2π0 12
Accept
Preliminary Preliminary
Δ vertex time < 3nsΔ KL mass < 15 MeV/c2
Min. halfEt > 350 MeV
KL pt < 50 MeV/c
KL χz2 < 20
Δπ0 mass < 6 MeV/c2
Δπ0 z < 400 mm
Min. GammaE > 50 MeV
Min. Fiducial XY > 120 mm
Max. Fiducial R < 850 mm
Min. Cluster dist. > 150 mm
KL z 2000 -- 5400 mm
KL beam exit XY < 50 mm
Max. shape χ2 < 5
CV Veto < 1.5 MeV
MB Veto < 5 MeV
CsI Veto < 3 MeV(distance dependent)
KL→2π0 event display
Rec. mass distribution Rec. momentum distribution
KL→3π0
KL→2π0
(loose veto)
Simulation well reproduced data (KL yield, spectrum, detector response).
From May run
Trigger quality check
17
a
CsI Trigger• CsIの総エネルギーに対して閾値550MeV を設定。
• Trigger Rate:120kHz
• OnlineとOfflineの違い: Gain補正、Pedestalの変動
13
Lv1
CsIの総和の波形
Time [clock]
Puls
e He
ight
[ADC
cou
nts]
CsI: Offline Energy Distribution
Threshold550MeV
preliminary
Threshold:Height-Pedestal>5000 ADCcount
132013年9月21日土曜日
CsI total energy (offline analysis)
MB
NCC
CV
CC03
Threshold check (with minimum bias data) Blue: all Red: with on-time hit flag
Online threshold= 50MeV
thr.=1MeV
thr.=60MeV thr.=60MeV
Trigger Rate Stability• いずれも RMS/Mean=1~2%で安定。• Lv1Trigger のRequestとAcceptの違いはL2のLiveTime
• Lv1 Trigger 自体は ほぼ dead time less
• Lv2 Triggerにはデッドタイムがある。
9
#of Trig./Spill(1spill~2sec)
Lv1 TriggerRequest
Lv1 TriggerAccept
Lv2 TriggerAccept
92013年9月21日土曜日
Stability of trigger (Ratio of Lv1 accept/request indicates Lv2 live time.)
Date
From May run
Veto detector response
18
M(4γ) w/o veto cut
Entries 6321Mean 357.3RMS 75.2Underflow 0Overflow 33Integral 6288
2#
of e
vent
s/10
MeV
/c
0
100
200
300
400
500
600Entries 6321Mean 357.3RMS 75.2Underflow 0Overflow 33Integral 6288
massLRec. K
Entries 4178Mean 344.3RMS 64.12Underflow 0Overflow 21.55Integral 5606
Entries 4178Mean 344.3RMS 64.12Underflow 0Overflow 21.55Integral 5606Entries 18164Mean 488.7RMS 40.89Underflow 0Overflow 0.2084Integral 540.6
Entries 18164Mean 488.7RMS 40.89Underflow 0Overflow 0.2084Integral 540.6Entries 107Mean 347.9RMS 77.94Underflow 0Overflow 0Integral 92.31
Entries 107Mean 347.9RMS 77.94Underflow 0Overflow 0Integral 92.31
Entries 18164Mean 488.7RMS 40.89Underflow 0Overflow 0.2084Integral 540.6
Entries 4178Mean 344.3RMS 64.12Underflow 0Overflow 21.55Integral 5606
Entries 4178Mean 344.3RMS 64.12Underflow 0Overflow 21.55Integral 5606
Entries 4178Mean 344.3RMS 64.12Underflow 0Overflow 21.55Integral 5606
Entries 107Mean 347.9RMS 77.94Underflow 0Overflow 0Integral 92.31
Entries 107Mean 347.9RMS 77.94Underflow 0Overflow 0Integral 92.31
Entries 107Mean 347.9RMS 77.94Underflow 0Overflow 0Integral 92.31
Entries 6321Mean 357.3RMS 75.2Underflow 0Overflow 33Integral 6288
Data MC0/3ALK MC0/0/ALK
MC0/-/+/ALK
]2mass [MeV/c300 400 500 600 700
300 400 500 600 7002D
ata/
MC
/10
MeV
/c
0.51
1.52
Preliminary
CV total energyEntries 79747Mean 0.3576RMS 0.6119Underflow 7711Overflow 1250Integral 7.079e+04
energy [MeV]0 1 2 3
# of
eve
nts/0
.05
MeV
210
310
410
Entries 79747Mean 0.3576RMS 0.6119Underflow 7711Overflow 1250Integral 7.079e+04
CV Veto total energy
Entries 56316Mean 0.3154RMS 0.5354Underflow 5352Overflow 753Integral 6.975e+04
Entries 56316Mean 0.3154RMS 0.5354Underflow 5352Overflow 753Integral 6.975e+04Entries 24676Mean 0.2736RMS 0.4822Underflow 54.24Overflow 5.329Integral 675.1
Entries 24676Mean 0.2736RMS 0.4822Underflow 54.24Overflow 5.329Integral 675.1Entries 2839Mean 1.714RMS 0.9399Underflow 57.8Overflow 453.8Integral 1938
Entries 2839Mean 1.714RMS 0.9399Underflow 57.8Overflow 453.8Integral 1938
Entries 79747Mean 0.3576RMS 0.6119Underflow 7711Overflow 1250Integral 7.079e+04
Data MC0/3ALK MC0/0/ALK
MC0/-/+/ALK
energy [MeV]0 1 2 3
0 1 2 3
Dat
a/M
C/0
.05
MeV
0.51
1.52
Preliminary
MB total energyEntries 79747Mean 16.97RMS 19.42Underflow 0Overflow 3Integral 7.974e+04
energy [MeV]0 50 100 150 200
# of
eve
nts/5
MeV
1
10
210
310
410Entries 79747Mean 16.97RMS 19.42Underflow 0Overflow 3Integral 7.974e+04
CBAR Inner Veto energy
Entries 56316Mean 17.16RMS 18.94Underflow 0Overflow 2.694Integral 7.586e+04
Entries 56316Mean 17.16RMS 18.94Underflow 0Overflow 2.694Integral 7.586e+04Entries 24676Mean 2.349RMS 8.747Underflow 0Overflow 0Integral 734.6
Entries 24676Mean 2.349RMS 8.747Underflow 0Overflow 0Integral 734.6Entries 2839Mean 8.681RMS 15.89Underflow 0Overflow 0Integral 2449
Entries 2839Mean 8.681RMS 15.89Underflow 0Overflow 0Integral 2449
Entries 79747Mean 16.97RMS 19.42Underflow 0Overflow 3Integral 7.974e+04
Data MC0/3ALK MC0/0/ALK
MC0/-/+/ALK
energy [MeV]0 50 100 150 200
0 50 100 150 200
Dat
a/M
C/5
MeV
0.51
1.52
Preliminary
Entries 79747Mean 340RMS 65.15Underflow 0Overflow 289Integral 7.946e+04
]2mass [MeV/c300 400 500 600 700
2#
of e
vent
s/10
MeV
/c
10
210
310
410 Entries 79747Mean 340RMS 65.15Underflow 0Overflow 289Integral 7.946e+04
massLRec. K
Entries 56316Mean 337.6RMS 62.88Underflow 0Overflow 266.7Integral 7.559e+04
Entries 56316Mean 337.6RMS 62.88Underflow 0Overflow 266.7Integral 7.559e+04Entries 24676Mean 487.8RMS 43Underflow 0Overflow 0.4168Integral 734.2
Entries 24676Mean 487.8RMS 43Underflow 0Overflow 0.4168Integral 734.2Entries 2839Mean 350.2RMS 84.31Underflow 0Overflow 6.901Integral 2442
Entries 2839Mean 350.2RMS 84.31Underflow 0Overflow 6.901Integral 2442
Entries 24676Mean 487.8RMS 43Underflow 0Overflow 0.4168Integral 734.2
Entries 56316Mean 337.6RMS 62.88Underflow 0Overflow 266.7Integral 7.559e+04
Entries 56316Mean 337.6RMS 62.88Underflow 0Overflow 266.7Integral 7.559e+04
Entries 56316Mean 337.6RMS 62.88Underflow 0Overflow 266.7Integral 7.559e+04
Entries 2839Mean 350.2RMS 84.31Underflow 0Overflow 6.901Integral 2442
Entries 2839Mean 350.2RMS 84.31Underflow 0Overflow 6.901Integral 2442
Entries 2839Mean 350.2RMS 84.31Underflow 0Overflow 6.901Integral 2442
Entries 79747Mean 340RMS 65.15Underflow 0Overflow 289Integral 7.946e+04
Data MC0/3ALK MC0/0/ALK
MC0/-/+/ALK
]2mass [MeV/c300 400 500 600 700
300 400 500 600 7002D
ata/
MC
/10
MeV
/c
0.51
1.52
Preliminary
•MB total E<5MeV•CV total E<1.5MeV•Only 4 clusters in CsI
• Analysis using minimum bias data
• Comparison between data and simulation
Preparation for next-level run
• Upgrade of barrel photon veto• Add Inner Barrel (IB) to increase radiation length
(Realization of thicker barrel photon veto, planned in the proposal)
• Completion of Beam Hole Photon Veto (BHPV)• Design: 25 modules, Current: 12 modules
• R&D of new beam hole charged veto (BHCV) for higher intensity
• Upgrade of trigger system
19
Osaka, Chicago, KEK, ...
Kyoto, Yamagata
Kyoto, Korean groups
Michigan, Chicago, Arizona State, Osaka, ...
OK T�
�s
d
KAON13 @ Univ. of Michigan Ann Arbor
Principle• KL pencil beam• 2γ + nothing
• Calorimeter + Hermetic veto
3
FB NCC MB CVCsI calorimeter
CC03OEV
CC04 CC05 CC06 BHCV BHPV
LCVBCVHINEMOS
Saturday, April 20, 2013
10m
Vacuum chamber
KL
Decay region
primary p(30GeV)
target
!, n
20m beam lineSweeping magnet and collimator
KL
Hermetic veto Calorimeter
Charged
!
!
"
"
"
"
!!
!"#$%&$ '
!"##$%&'()*+,*-(&%
.(&%*/0"1$#(*&1'(0*2"##$%&'"0*&#$34%(4'*5*6+
7"8(&-#(*'9"*:'&3(*2"##$%&'"0!"#$%&'()*+*#,(-#.%/#012345#678#9:!:#
;(<<*=(-*.&(>?#@AB#3#CDE#FDG7GH#IJI
K"#!*L*%*M%&#/.#*<"?#0N>"#0"#3NN<"#2%OM"#IG#FDG77H#GECPG7
T. Shimogawa et al., NIMA 623, (2010) 585
Inner Barrel (IB)
MB 14X0 + IB 5X0
3m
MB 14X0
Front Barrel5.5m
Decay region
Calorimeter
• To suppress KL→2π0 background to the level of 10-11
(necessary to go beyond G-N limit)
• 25 layers of Pb1mm+scinti.5mm sandwich, WLSF readout
20
Status of Inner Barrel
• Fabrication is underway.• Pb, scinti, WLSF have been delivered.• Grooving scintillator plate is in process.• Glueing WLSF to scintillator is being done at
KEK-Tsukuba.
• Will complete fabrication of scintillator+WLSF layers in this fiscal year.
• Mechanical structure is being designed, collaborating with an engineer of U of Chicago.
• Construction and installation schedule will be considered along with the whole plan of hadron hall works.
21
実機の製作
*現在44枚のシンチレータが製作済み
*8月中旬より実機のためのシンチレータとWLSFの接着作業を開始*自動ステージによる接着剤の塗布 *紫外線照射により硬化
152013年9月20日金曜日
UV curing of adhesive
実機の製作
*現在44枚のシンチレータが製作済み
*8月中旬より実機のためのシンチレータとWLSFの接着作業を開始*自動ステージによる接着剤の塗布 *紫外線照射により硬化
152013年9月20日金曜日
application of glueSupported by KAKENHI Grant-in-Aid and Japan-US program (+ KEK budget)
Other works to do (other than upgrade)
• We must move our counting house to other place,in accordance with construction of COMET building.
• Maybe twice; current house -> temporal hut -> room in COMET building
• We must rebuild the shield wall of our experimental area, when new K1.1 beam line is seated.
• To accommodate the K1.1 beam dump...
• We must move our trigger system, which is now located just outside of our experimental area.
• To release the space outside the experimental area, which will be used for new beam lines in future.
22
Schedule (and budget) will be considered with the whole work plan in hadron hall.
Summary
• KOTO completed detector construction for 1st physics run and took physics data in May 2013• Original goal: to cross the Grossman-Nir limit • Achieved: ~4 day run with 24kW beam;
accumulated ~1/5 of planned POT
• We are now analyzing the data, expecting we can improve KEK-E391a upper limit.
• Preparation for next-level physics run is also underway.• Fabrication of Inner Barrel, etc...
23
Backup
25
40ns
20mV
Sample of CsI signal
Raw signal Recorded waveform(after 10-pole gaussian filter)
26
Dead time in Lv2
Lv2 Trigger module
FlashADC
Data
2Gb memory
Buffer
Lv2TriggerControl
CoE
Write
Optical link(2.5Gbps)
1Gbps Ethernet
2Gb memory
Readout Data
Lv1trigger
Lv3PCfarm
Lv2 triggerLv1Trigger
BufferFull
136µs/event
• Lv2 BUSY when input FIFOs (depth=7) are occupied;• in case rejected: just clear FIFO = enough fast (>100kHz)• in case accepted: data transfer from FIFO to memory limits the time
to release FIFO ==> capacity ~7kHz
27
Another background is !0 production from beam neutrons interactingwith residual gas in the decay region. In order to suppress this background,the decay volume is evacuated to 10!5 Pa, as was obtained in E391a byseparating the detector and the decay region with a thin film.
Figure 14: Schematic view of detector setup.
4.3.1 Calorimeter
The electromagnetic calorimeter measures the positions and energies of pho-tons to reconstruct !0 in the K0
L ! !0"" decay. In the E391a experiment,the Calorimeter was made of 576 pure CsI crystals. Each crystal was 7.0"7.0cm2 and 30-cm long (16 X0) [59].
For the experiment at J-PARC, we plan to replace these crystals with thepure CsI crystals used in the calorimeter of the Fermilab KTeV experiment.The crystals, called “KTeV CsI crystals” hereafter, are smaller in the crosssection and longer in the beam direction (50 cm, 27 X0) than the crystals inE391a, which ensures us much better performance in the new experiment.Figure 15 shows the layout of the new Calorimeter, which then consists of2576 crystals. These crystals are of two sizes, 2.5 " 2.5 " 50 cm3 for thecentral region (2240 blocks), and 5.0"5.0"50 cm3 for the outer region (336blocks) of the Calorimeter.
The reasons for replacing the calorimeter are as follows.
• Reduce the probability of missing photons due to fused clusters.If two photons hit the Calorimeter close to each other, the generatedshowers will overlap and be misidentified as a single photon. Figure 16shows an event display for two photons that enter the CsI Calorimeterwith 6-cm separation. By using the KTeV CsI crystals, two photons
28
K0L � 3�0
Blue: events with 2γ clustersRed: after kinematic cuts for analysis
Require all photons in CsI
COE distribution (simulation)
28
# of triggers in May runtrigger type condition Prescale
factor# of events@L1(/spill)
# of events@L2(/spill)
physics Et&Veto&COE 1 27K 5.2K
normalization Et&Veto 30 0.9K 0.7K
Minimum bias Et 300 0.9K 0.7K
3pi0 calibration Et&RC&Veto 10 0.4K 0.3Kcosmic ray(3types) 1 0.2K 0.2Kexternal(2types)
1(1200 for TMON) 0.2K 0.2K
L1 Request: 28.0K events/spill, L1 Accept : 23.0K events/spillL2 Accept : 7.4K events/spill
313年7月25日木曜日
29
Cut conditions for KL→3π0, 2π0
OK T�
�s
d
日本物理学会 2013年秋季大会 21aSL01
p [MeV/c]0 1000 2000 3000 4000 5000 6000 7000
# of
eve
nts /
100
MeV
1
10
210
310
hKlongMom3pi0Entries 426305Mean 1.266± 2255 RMS 0.8954± 826.8 Underflow 0Overflow 0Integral 7.89e+04
Data
MC0!3"LK
momemtumLRec. K
hRatioEntries 247Mean 117.9± 3860 RMS 83.33± 1853 Underflow 0Overflow 0Integral 63.91
momentum [MeV/c]Lrec. K0 1000 2000 3000 4000 5000 6000 7000
Rat
io (D
ata/
MC
)
00.20.40.60.8
11.21.41.61.8
2 hRatioEntries 247Mean 117.9± 3860 RMS 83.33± 1853 Underflow 0Overflow 0Integral 63.91
• Mass, Momentum ともに再現できている
KL→3π0 11
ener
gy (l
og) [
MeV
]
0.5
1
1.5
2
2.5
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI energy ( > 3MeV )CSI energy ( > 3MeV )
ener
gy (l
og) [
MeV
]
0.5
1
1.5
2
2.5
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI energy in clusterCSI energy in clusterRun 13710
Node 000
DstEntry 00089
nGammas 6
MyCutCondition 0
MyVetoCondition 0
KL mass 491.839923
ExtraClusterDeltaTime 0.000000
time
[ns]
150
160
170
180
190
200
210
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI time ( > 3MeV )CSI time ( > 3MeV )
time
[mm
]
202
204
206
208
210
212
214
216
218
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI time in clustersCSI time in clusters
time
[mm
]
202
204
206
208
210
212
214
216
218
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI time in gammasCSI time in gammas
]2mass [MeV/c400 420 440 460 480 500 520 540 560 580 600
2#
of e
vent
s / 2
MeV
/c
1
10
210
310
410
hKlongMass3pi0Entries 456640Mean 0.01634± 498.2 RMS 0.01155± 10.97 Underflow 0Overflow 1136Integral 8.338e+04
Data
MC0!3"LK
massLRec. K
hRatioEntries 2735Mean 1.068± 505.9 RMS 0.7548± 55.83 Underflow 0Overflow 1.113Integral 98.94
]2 invariant mass [MeV/c#6400 420 440 460 480 500 520 540 560 580 600
Rat
io (D
ata/
MC
)
00.20.40.60.8
11.21.41.61.8
2 hRatioEntries 2735Mean 1.068± 505.9 RMS 0.7548± 55.83 Underflow 0Overflow 1.113Integral 98.94
Accept
Δ vertex time < 3ns
Δ KL mass < 15 MeV/c2
Min. halfEt > 350 MeV
KL pt < 50 MeV/c
KL χz2 < 20
Δπ0 mass < 10 MeV/c2
Δπ0 z < 400 mm
Min. GammaE > 50 MeV
Min. Fiducial XY > 120 mm
Max. Fiducial R < 850 mm
Min. Cluster dist. > 150 mm
KL z 2000 -- 5400 mm
KL→3π0 event display
Rec. mass distribution Rec. momentum distribution
OK T�
�s
d
日本物理学会 2013年秋季大会 21aSL01
0 1000 2000 3000 4000 5000 6000
# of
eve
nts /
100
MeV
20
40
60
80
100
120 Data MC0!2"LK MC0!3"LK
MC0!-!+!"LK
momemtumLRec. K
hRatioEntries 102Mean 159± 3382 RMS 112.5± 1609 Underflow 0Overflow 0Integral 57.07
momentum [MeV/c]0 1000 2000 3000 4000 5000 6000
Rat
io (D
ata/
MC
)
00.20.40.60.8
11.21.41.61.8
2 hRatioEntries 102Mean 159± 3382 RMS 112.5± 1609 Underflow 0Overflow 0Integral 57.07
250 300 350 400 450 500 550 600
2#
of e
vent
s / 4
MeV
/c
100
200
300
400
500
600
700 Data MC0!2"LK MC0!3"LK
MC0!-!+!"LK
massLRec. K
hRatioEntries 2882Mean 1.765± 433.2 RMS 1.248± 94.78 Underflow 0Overflow 1.06Integral 81.91
]2 invariant mass [MeV/c#4250 300 350 400 450 500 550 600
Rat
io (D
ata/
MC
)
00.20.40.60.8
11.21.41.61.8
2 hRatioEntries 2882Mean 1.765± 433.2 RMS 1.248± 94.78 Underflow 0Overflow 1.06Integral 81.91
ener
gy (l
og) [
MeV
]
0.5
1
1.5
2
2.5
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI energy ( > 3MeV )CSI energy ( > 3MeV )
ener
gy (l
og) [
MeV
]
0.5
1
1.5
2
2.5
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI energy in clusterCSI energy in clusterRun 13669
Node 000
DstEntry 00081
nGammas 4
MyCutCondition 0
MyVetoCondition 0
KL mass 501.087490
ExtraClusterDeltaTime 0.000000
time
[ns]
100
150
200
250
300
350
400
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI time ( > 3MeV )CSI time ( > 3MeV )
time
[mm
]
198
200
202
204
206
208
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI time in clustersCSI time in clusters
time
[mm
]
198
200
202
204
206
208
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI time in gammasCSI time in gammas
• こちらもMass, Momentum ともに再現している
KL→2π0 12
Accept
Δ vertex time < 3nsΔ KL mass < 15 MeV/c2
Min. halfEt > 350 MeV
KL pt < 50 MeV/c
KL χz2 < 20
Δπ0 mass < 6 MeV/c2
Δπ0 z < 400 mm
Min. GammaE > 50 MeV
Min. Fiducial XY > 120 mm
Max. Fiducial R < 850 mm
Min. Cluster dist. > 150 mm
KL z 2000 -- 5400 mm
KL beam exit XY < 50 mm
Max. shape χ2 < 5
CV Veto < 1.5 MeV
MB Veto < 5 MeV
CsI Veto < 3 MeV(distance dependent)
KL→2π0 event display
Rec. mass distribution Rec. momentum distribution
KL→3π0 KL→2π0
30
OK T�
�s
d
日本物理学会 2013年秋季大会 21aSL01
0 1000 2000 3000 4000 5000 6000
# of
even
ts /
100
MeV
20406080
100120140160
Data MC!2"LK MC0#3"LK MC0#2"LK
MC0#-#+#"LK MC$e#"LK MC!$e#"LK
momemtumLRec. K
hRatioEntries 62Mean 184.7± 3323 RMS 130.6± 1454 Underflow 0Overflow 0Integral 46.65
momentum [MeV/c]0 1000 2000 3000 4000 5000 6000
Rat
io (D
ata/
MC
)
00.20.40.60.8
11.21.41.61.8
2 hRatioEntries 62Mean 184.7± 3323 RMS 130.6± 1454 Underflow 0Overflow 0Integral 46.65
0 20 40 60 80 100 120 140 160 180 200
# of
eve
nts /
2.5
MeV
/c
20406080
100120140160180200 Data
MC!2"LK MC0#3"LK MC0#2"LK
MC0#-#+#"LK MC$e#"LK MC!$e#"LK
transverse momentumLRec. K
hRatioEntries 2612Mean 1.132± 101.5 RMS 0.8004± 57.85 Underflow 0Overflow 1.117Integral 82.26
transverse momentum [MeV/c]0 20 40 60 80 100 120 140 160 180 200
Rat
io (D
ata/
MC
)
00.20.40.60.8
11.21.41.61.8
2 hRatioEntries 2612Mean 1.132± 101.5 RMS 0.8004± 57.85 Underflow 0Overflow 1.117Integral 82.26
ener
gy (l
og) [
MeV
]
0.6
0.8
1
1.2
1.4
1.6
1.8
2
2.2
2.4
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI energy ( > 3MeV )CSI energy ( > 3MeV )
ener
gy (l
og) [
MeV
]
0.6
0.8
1
1.2
1.4
1.6
1.8
2
2.2
2.4
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI energy in clusterCSI energy in clusterRun 13710
Node 010
DstEntry 04094
nGammas 2
MyCutCondition 0
MyVetoCondition 0
KL mass 0.000000
ExtraClusterDeltaTime 0.000000
time
[ns]
185
190
195
200
205
210
215
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI time ( > 3MeV )CSI time ( > 3MeV )
time
[mm
]
208
210
212
214
216
218
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI time in clustersCSI time in clusters
time
[mm
]
208
210
212
214
216
218
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI time in gammasCSI time in gammas
• Transverse momentum, Momentum ともに再現できている• KL→2γはKL massを仮定するため、mass分布は無し
KL→2γ 13
Accept
Preliminary Preliminary
Δ vertex time < 3ns
Min. halfEt > 350 MeV
KL pt < 50 MeV/c
Min. GammaE > 400 MeV
Max. GammaE > 600 MeV
Min. Fiducial XY > 120 mm
Max. Fiducial R 450 -- 850 mm
Min. Cluster dist. > 600 mm
KL z 2000 -- 5000 mm
Max. shape χ2 < 5
CV Veto < 1 MeV
MB Veto < 5 MeV
CsI Veto < 3 MeV(distance dependent)
KL→2γ event display
Rec. transverse momentum distribution Rec. momentum distribution
KL→2γ
OK T�
�s
d
日本物理学会 2013年秋季大会 21aSL01
0 1000 2000 3000 4000 5000 6000
# of
even
ts /
100
MeV
20406080
100120140160
Data MC!2"LK MC0#3"LK MC0#2"LK
MC0#-#+#"LK MC$e#"LK MC!$e#"LK
momemtumLRec. K
hRatioEntries 62Mean 184.7± 3323 RMS 130.6± 1454 Underflow 0Overflow 0Integral 46.65
momentum [MeV/c]0 1000 2000 3000 4000 5000 6000
Rat
io (D
ata/
MC
)
00.20.40.60.8
11.21.41.61.8
2 hRatioEntries 62Mean 184.7± 3323 RMS 130.6± 1454 Underflow 0Overflow 0Integral 46.65
0 20 40 60 80 100 120 140 160 180 200
# of
eve
nts /
2.5
MeV
/c
20406080
100120140160180200 Data
MC!2"LK MC0#3"LK MC0#2"LK
MC0#-#+#"LK MC$e#"LK MC!$e#"LK
transverse momentumLRec. K
hRatioEntries 2612Mean 1.132± 101.5 RMS 0.8004± 57.85 Underflow 0Overflow 1.117Integral 82.26
transverse momentum [MeV/c]0 20 40 60 80 100 120 140 160 180 200
Rat
io (D
ata/
MC
)
00.20.40.60.8
11.21.41.61.8
2 hRatioEntries 2612Mean 1.132± 101.5 RMS 0.8004± 57.85 Underflow 0Overflow 1.117Integral 82.26
ener
gy (l
og) [
MeV
]
0.6
0.8
1
1.2
1.4
1.6
1.8
2
2.2
2.4
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI energy ( > 3MeV )CSI energy ( > 3MeV )
ener
gy (l
og) [
MeV
]
0.6
0.8
1
1.2
1.4
1.6
1.8
2
2.2
2.4
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI energy in clusterCSI energy in clusterRun 13710
Node 010
DstEntry 04094
nGammas 2
MyCutCondition 0
MyVetoCondition 0
KL mass 0.000000
ExtraClusterDeltaTime 0.000000
time
[ns]
185
190
195
200
205
210
215
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI time ( > 3MeV )CSI time ( > 3MeV )
time
[mm
]
208
210
212
214
216
218
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI time in clustersCSI time in clusters
time
[mm
]
208
210
212
214
216
218
x [mm]-1000 -800 -600 -400 -200 0 200 400 600 800 1000
y[m
m]
-1000
-800
-600
-400
-200
0
200
400
600
800
1000
CSI time in gammasCSI time in gammas
• Transverse momentum, Momentum ともに再現できている• KL→2γはKL massを仮定するため、mass分布は無し
KL→2γ 13
Accept
Δ vertex time < 3ns
Min. halfEt > 350 MeV
KL pt < 50 MeV/c
Min. GammaE > 400 MeV
Max. GammaE > 600 MeV
Min. Fiducial XY > 120 mm
Max. Fiducial R 450 -- 850 mm
Min. Cluster dist. > 600 mm
KL z 2000 -- 5000 mm
Max. shape χ2 < 5
CV Veto < 1 MeV
MB Veto < 5 MeV
CsI Veto < 3 MeV(distance dependent)
KL→2γ event display
Rec. transverse momentum distribution Rec. momentum distribution
Other works to do- against activities from primary beam line -
31
Put$200$water+tanks$at$the$north+upstream$wall$in$our$area�
Es6mated$direc6on$of$par6cles$$(from$MB$rate$analysis)�
Temporal countermeasure in March = Shielding by a stack of water tanks
Other works to do- against activities from primary beam line -
32
2.E+04'
2.E+05'
1'2' 3'
4'5'
6'
7'
8'
9'
10'
11'
12'
13'14'
15'16'17'
18'19'20'
21'
22'
23'
24'
25'
26'
27'
28'
29'30'
31' 32'Main%barrel%outer-module%rate�
1�Run'3�8��beam6tuning�������beam6tuning���
north'
south'
top'
bo?om'
top'
north' south'
bo?om'Primary'beam'line� Embedded'iron�
Water6tanks�
Jan runMarch (before tuning)March (after tuning)
Plan to use heavier shielding material (iron) to reduce activities more.