Transcript pptx

HLAB meeting
Status Report
Toshi Gogami
1/Nov/2011
JLab E05-115 collaboration, 2009, JLab Hall-C
Contents
• (e,e’K+) experiments in JLab & Mainz.
• JLab E05-115 (2009)
– The number of events for high multiplicity data
JLab & Mainz
e + p ➝ e’ + K+ + Λ
Spectroscopic experiment
by (e,e’K+) reaction
Feynman diagram
e
p
e
u
u
d
γ* u K+
–s
s
u Λ
d
pe’
e + p ➝ e’ + K+ + Λ
e’-Spectrometer
eγ*
p
n
Λ
target nucleus
Missing Mass HHY
K+
K+-Spectrometer
pK+
Experimental setup of JLab E05-115
p(e,e’K+)Λ,(Σ0)
HES
e’
Splitter Magnet
HKS
K+
Experimental setup of JLab E05-115
Data taking : Aug-Nov 2009
p(e,e’K+)Λ
Tracking
2×10-4
7 [msr]
3 – 12 [deg]
7Li
2×10-4
8.5 [msr]
2 – 12 [deg]
, 9Be , 10B , 12C , 52Cr
( 7ΛHe , 9ΛLi , 10ΛBe , 12ΛB , 52ΛV )
CH2, H2O
2 - 50 [μA]
10 - 300 [THz]
Discrepancy of Number of Λ
CH2 Target
The number of Λ
NΛ ≈ Nexpect
12C
quasi-free
H2O Target
Λ
The number of Λ
NΛ ≈ ¼ Nexpect
Λ
Σ0
Acc. b.g.
REAL DATA
Black : hit wires
Blue : selected wires
Red : track
Σ0
16O
quasi-free
Acc. b.g.
REAL DATA
Black : hit wires
Blue : selected wires
Red : track
Lost events that we are interested in in tracking procedure.
ECT*/JSPS core to core, T.Gogami (2011)
7
New tracking code
Results of
Introduction of new Tracking Code
Increased !
Increased !
• NΛ ≈ ¼ Nexpect
H2O
 NΛ ≈ ½ Nexpect
For further improvement
• Efficiency
– Tracking
– TOF detectors
• Discarded events
Rates of the KDC wires
KDC1-u
< 510 kHz
KDC1-u’
77124
KDC1-x
< 350 kHz
77124 ( 52Cr target )
KDC1
KDC2-u
< 290 kHz
KDC2-u’ ~22 MHz
KDC2-x
< 230 kHz
Rate [kHz]
52Cr,
KDC1-x’52
KDC1-v
Cr, 77124
KDC1-v’
Wire Number
KDC2
5×5
~11
MHz
KDC2-x’
KDC2-v
KDC2-v’
Rates of the HKS TOF detectors
Events which are discarded
KDC2
KDC1
52Cr,
77124
Events which are discarded
KDC2
• Where and why are these events discarded ?
• Are these events threw away by correct cut condition?
KDC1
52Cr,
77124
Summary
• Need to improve analysis code for high multiplicity data
– Efficiencies
– Rescue discarded events
END
JLab Hall-C circuit room, 5/Nov/2009
Backup
Decay Pion Spectroscopy to Study -Hypernuclei
Example:
Direct Production
e’
K+
12
C
*
e
Ground state doublet
12
of B
p
12

B


E.M.
12

Hypernuclear States:
s (or p) coupled to
low lying core nucleus
B and 
Bg.s.
21-

C
12
Weak mesonic two body decay
~150 keV
0.0
Decay Pion Spectroscopy for Light and Exotic -Hypernuclei
Fragmentation Process
Example: e’
K+
Access to variety of light
and exotic hypernuclei,
some of which cannot be
produced or measured
precisely by other means
12
e
C
*
12

B
p

*
Fragmentation
(<10-16s)
s
4

Highly Excited
Hypernuclear States:
s coupled to HighLying core nucleus, i.e.
particle hole at s orbit


H

4

Hg.s.
-


4
He
Weak mesonic two body
decay (~10-10s)
Spectroscopic experiment
by (e,e’K+) reaction
e
p
e’-Spectrometer
e-
e
u
u
d
pe’
e + p ➝ e’ + K+ + Λ
Feynman diagram
γ* u K+
–s
s
u Λ
d
γ*
p
n
Λ
target nucleus
1.
2.
3.
Missing Mass HHY
K+
K+-Spectrometer
pK+
Large Momentum transfer
• Λ can be bounded in deeper orbit
Λ’s spin at forward angle
• Spin flip ~ spin non-flip
Proton  Λ,Σ0
• Absolute mass scale calibration
JLab E05-115 experimental setup
e + p → e’ + Λ + K+
2×10-4
7 [msr]
3 – 12 [deg]
7Li
2×10-4
8.5 [msr]
2 – 12 [deg]
, 9Be , 10B , 12C , 52Cr
• (e,e’K+) experiment
Primary beam
• High intensity
Thin target (~100 [mg/cm2])
• High quality
APFB2011 in Korea (T.Gogami)
1.
2.
3.
Coincidence experiment
(K+ and e-)
Small cross section
( ~100 [nb/sr] ) 1/1000
Energy resolution
21
Sub MeV (FWHM)
Experimental setup of JLab E05-115
Data taking : Aug-Nov 2009
p(e,e’K+)Λ
HKS chamber wire configuration
Tracking
2×10-4
7 [msr]
3 – 12 [deg]
7Li
2×10-4
8.5 [msr]
2 – 12 [deg]
, 9Be , 10B , 12C , 52Cr
( 7ΛHe , 9ΛLi , 10ΛBe , 12ΛB , 52ΛV )
CH2, H2O
2 - 50 [μA]
10 - 300 [THz]
HKS Drift Chamber hit selection
with TOF detectors
Gravity
• GREEN region
Selective region
• RED markers
Selected hit wires
• BLACK markers
Rejected hit wires
Particle direction
Results of
Introduction of new Tracking Code
Increased !
Increased !
• NΛ ≈ ¼ Nexpect
H2O
 NΛ ≈ ½ Nexpect
Theoretical calculation of A=7 system
Four-body cluster model for T=1 triplet hypernuclei
JLab E01-011
7Li(e,e’K+)7 He
(E.Hiyama et al., NPC 80, 2009)
Λ
-6.650.03 0.2 MeV
α+Λ+N+N
from α  n n
Preliminary
-B (MeV)
CSB interaction is determined to
reproduce BΛ of 4ΛH and 4ΛHe.
APFB2011 in Korea (T.Gogami)
25
(e,e’K+) experiment in JLab Hall-C
2000
1st
2005
Proof of feasibility
generation exp. JLab E89-009
ENGE(e’) + SOS(K+)
12 B
Λ
~ 750 [keV] (FWHM)
sΛ
ΛB
E89-009
pΛ
~750 [keV] (FWHM)
Establish exp. method
2nd generation exp. JLab E01-011
ENGE(e’) + HKS(K+) + Tilt method
7 He,12 B,28 Al
Λ
Λ
Λ
~ 500 [keV] (FWHM)
2009
12C(e,e’K+)12
Confirming stage
Up to Medium heavy
3rd generation exp. JLab E05-115
HES(e’) + HKS(K+) + Tilt method
7 He,9 Li,10 Be, 12 B,52 V
Λ
Λ
Λ
Λ
Λ
≤ 500 [keV] (FWHM)
APFB2011 in Korea (T.Gogami)
Analysis stage
28Si(e,e’K+)28
ΛAl
E01-011
sΛ
pΛ
dΛ
~600 [keV] (FWHM)
Preliminary
26
(e,e’K+) experiment in JLab Hall-A
12C(e,e’K+)12
sΛ
ΛB
pΛ
2007
JLab E94-107
HRS’s (K+, e+)+ septum
9 Li,12 B,16 N
Λ
Λ
Λ
~ 670 [keV] (FWHM)
16O(e,e’K+)16
sΛ
APFB2011 in Korea (T.Gogami)
27
ΛN
HESのバックグラウンド
• ハイパー核生成に関係した電子
赤
• HES側のバックグラウンド
– 制動放射起因の電子 緑
– Møller散乱起因の電子 青
モンテカルロシミュレーションでそれ
ぞれ150000イベント生成させた
バックグラウンドである、0o方向に集中す
るMøller散乱・制動放射起因電子を避け
るTilt法を導入
e’ rate
Tilt法の概略図
第一世代
200 [MHz]
APFB2011 in Korea (T.Gogami)
第二世代
1 [MHz]
28
Tilt角の最適化
Figure of Merit (FoM)
•
•
•
6.5o
ハイパー核生成に関与した電子の計数率 S
Mφller散乱起因電子の計数率 NMφller
制動放射起因電子の計数率 NBrems
シミュレーションによる計数率の見積もり
Target
e’ rate [kHz]
10B
480
12C
558
52Cr
1780
APFB2011 in ビーム強度
Korea (T.Gogami)
30 [μA] , 100 [mg/cm2] を仮定
29
角度アクセプタンス
入射電子ビームのエネルギー
1.851 2.344 [GeV]
•バックグラウンドがより前方に集中
アクセプタンスをより前方へ
第二世代実験E01-011
•HESの角度アクセプタンスが広い
ハイパー核の収量が増加
第三世代実験E05-115
APFB2011 in Korea (T.Gogami)
30
Ei=2.344,ω=1.5[GeV]
運動量アクセプタンス
52
ΛV
g.s.
測定するハイパー核の生成領域を広
くカバーするように設計した。
HKSとHESの運度量の相関
立体角
•
•
•
一様に生成した全粒子の数をNGen
一様に生成した全粒子の立体角をΔΩGen
HESの最下流まで通過した粒子の数をNpass
立体角 ~6.5[msr] w/ splitter
APFB2011 in Korea (T.Gogami)
31
89Y(π+,K+)89
KEK-PS E369
89Y(π+,K+)89 Y
Λ
89Y(π+,K+)89
51V(π+,K+)51 V
Y,
Λ
Λ
KEK-PS E369
51V(π+,K+)51 V
Λ
ΛY
51V(π+,K+)51 V
Λ
APFB2011 in Korea (T.Gogami)
∆𝐸
𝐸
≈1.45 [MeV] (FWHM)
KEK-PS E369
12C(π+,K+)12 C
Λ
12C(π+,K+)12 C
Λ 32
E05-115 experimental motivation(2)
FULL(8)
FULL(4)
・・
・
1f7/2
1d3/2 FULL(4)
・・
・
n = 28
p = 24
52Cr
52
ΛV
7+ or
6+ f
6- or
5+ or
5- d
4- or
3- s
4+ p
ls splitting ∝ 2l+1
Λ
• ls splitting
• Core excited
Photo- and electro production of medium
mass Λ-hypernuclei ,P.Bydzovsky et al. (2008)
APFB2011 in Korea (T.Gogami)
33
Spectroscopic experiment
via (e,e’K+) reaction
Feynman diagram
e
p
e
u
u
d
γ* u K+
–s
s
u Λ
d
e + p ➝ e’ + K+ + Λ
e-
γ*
p
n
Λ
K+
target nucleus
measure
Missing mass : M2HY = (Ee + MT - EK+ - Ee’)2 - ( pe - pK+ - pe’)2
•Binding energy
•Cross section
APFB2011 in Korea (T.Gogami)
34
P.Bydzovsdy ,photo- and electro production
of medium mass Λ-hypernuclei, 2008
APFB2011 in Korea (T.Gogami)
35
Λ single particle energy
(e,e’K+) experiments in JLab
• E89-009 (2000)
• E94-107 (2004)
• E01-011 (2005)
• E05-115 (2009)
D.J.Millener et al. PRC 38, 6, 1988
Woods-Saxson potential with a depthAPFB2011
of 28 [MeV]
and
− 2in
/3Korea (T.Gogami)
a radius parameter 𝑟0 = 1.128 + 0.439𝐴
36
Feature of (e,e’K+) reaction
(e,e’K+)
(π+ , K+)
(K- , π-)
e + p ➝ e + K+ + Λ
π+ + n ➝ K + + Λ
K - + n ➝ π- + Λ
e
Reaction
p
e
u
u
d
γ* u K+
–s
s
u Λ
d
Momentum transfer
(Typical )
~300 [MeV/c]
Λ’s Spin
At forward angle
flip ≈ non-flip
Spin dependent structure
proton
Mirror lambda hypernuclei
Beam
High quality , high intensity
Energy resolution
(FWHM)
u +
–s K
d
n d
u
s
d Λ
u
~300 [MeV/c]
–u
s
–u
d π
d
n d
u
s
d Λ
u
K-
~90 [MeV/c]
Λ can be bounded in deeper orbit
Λ’s from
Target
u
–
d
π+
primary
non-flip
non-flip
neutron
neutron
secondary
secondary
Thin (~100 mg/cm2)
Thick(> a few [g/cm2] ) Thick(> a few [g/cm2] )
(Isotopically enriched)
APFB2011 in Korea (T.Gogami)
≤ 500 [keV]
1 – 3 [MeV]
Fine structure
1 – 3 [MeV]
37
Theoretical calculation of A=7 system
Four-body cluster model for T=1 triplet hypernuclei
JLab E01-011
7Li(e,e’K+)7 He
(E.Hiyama et al., NPC 80, 2009)
Λ
-6.650.03 0.2 MeV
α+Λ+N+N
from α  n n
Preliminary
-B (MeV)
CSB interaction is determined to
reproduce BΛ of 4ΛH and 4ΛHe.
APFB2011 in Korea (T.Gogami)
38
(e,e’K+) experiment in JLab Hall-C
2000
1st
2005
Proof of feasibility
generation exp. JLab E89-009
ENGE(e’) + SOS(K+)
12 B
Λ
~ 750 [keV] (FWHM)
sΛ
ΛB
E89-009
pΛ
~750 [keV] (FWHM)
Establish exp. method
2nd generation exp. JLab E01-011
ENGE(e’) + HKS(K+) + Tilt method
7 He,12 B,28 Al
Λ
Λ
Λ
~ 500 [keV] (FWHM)
2009
12C(e,e’K+)12
Confirming stage
Up to Medium heavy
3rd generation exp. JLab E05-115
HES(e’) + HKS(K+) + Tilt method
7 He,9 Li,10 Be, 12 B,52 V
Λ
Λ
Λ
Λ
Λ
≤ 500 [keV] (FWHM)
APFB2011 in Korea (T.Gogami)
Analysis stage
28Si(e,e’K+)28
ΛAl
E01-011
sΛ
pΛ
dΛ
~600 [keV] (FWHM)
Preliminary
39
(e,e’K+) experiment in JLab Hall-A
12C(e,e’K+)12
sΛ
ΛB
pΛ
2007
JLab E94-107
HRS’s (K+, e+)+ septum
9 Li,12 B,16 N
Λ
Λ
Λ
~ 670 [keV] (FWHM)
16O(e,e’K+)16
sΛ
APFB2011 in Korea (T.Gogami)
40
ΛN
Elementary process p(e,e’K+)Λ
~40 hours
(5 shifts)
JLab E05-115
p(e,e’K+)Λ,Σ0
Very preliminary
• p(e,e’K+)Λ,Σ0 are used for
Energy calibration
• Study of elementary
process
• Consistency check with
past experiment
APFB2011 in Korea (T.Gogami)
R. Bradford
et al. , FRC73, 2006
41
Single Λ hypernuclear spectroscopy
• (π+,K+), (K+,π+) spectroscopy
– CERN, BNL, KEK
• A = 7 – 208
• Resolution (FWHM) ~ a few MeV
• γ-ray spectroscopy with Ge detector
– KEK, J-PARC
• A=7 – 16
• Resolution (FWHM) ~ a few keV
• Decay pion spectroscopy
– Mainz Univ.
• A < 10
• Resolution (FWHM) < 100 keV
• (e,e’K+) spectroscopy
Determine Absolute value
– JLab, (Mainz Univ.)
• A=7 – 52
• Resolution (FWHM) ~ 500 keV
APFB2011 in Korea (T.Gogami)
42
(e,e’K+) reaction
(e,e’K+)
(π+ , K+)
(K- , π-)
e + p ➝ e + K+ + Λ
π+ + n ➝ K + + Λ
K - + n ➝ π- + Λ
e
Reaction
p
e
u
u
d
γ* u K+
–s
s
u Λ
d
Momentum transfer
(Typical )
~300 [MeV/c]
Λ’s Spin
At forward angle
flip ≈ non-flip
Spin dependent structure
proton
Mirror lambda hypernuclei
Beam
High quality , high intensity
Energy resolution
(FWHM)
u +
–s K
d
n d
u
s
d Λ
u
~300 [MeV/c]
–u
s
–u
d π
d
n d
u
s
d Λ
u
K-
~90 [MeV/c]
Λ can be bounded in deeper orbit
Λ’s from
Target
u
–
d
π+
primary
non-flip
non-flip
neutron
neutron
secondary
secondary
Thin (~100 mg/cm2)
Thick(> a few [g/cm2] ) Thick(> a few [g/cm2] )
(Isotopically enriched)
APFB2011 in Korea (T.Gogami)
≤ 500 [keV]
1 – 3 [MeV]
Fine structure
1 – 3 [MeV]
43
JLab CEBAF ( Continuance Electron
Beam Accelerator Facility )
• (e,e’K+) experiment
1.
2.
3.
Coincidence experiment
(K+ and e-)
Small cross section
( ~100 [nb/sr] ) 1/1000
Energy resolution
sub MeV (FWHM)
• Requirement for accelerator
1. high duty factor
2. high intensity
3. small emittance
small ΔE/E
CEBAF can satisfy
these requirements
Maximum beam energy
6.0[GeV]
Maximum beam intensity
200[μA/Hall]
Beam emittance
~2 [mm・μrad]
Thomas Jefferson
Beam energy spread
National Accelerator Facility
100 [m]
Beam bunch interval
<1×10-4
~2[ns]
(499[MHz])
APFB2011
in Korea
(T.Gogami)
44
(e,e’K+) experiment in JLab Hall-C
2000年
1st generation exp. JLab E89-009
ENGE(e’) + SOS(K+)
12 B
Λ
~ 900 [keV] (FWHM)
Proof of feasibility
2005年
Luminosity ×137
e’ rate
1/200
S/N
×2.7
2nd generation exp. JLab E01-011
ENGE(e’) + HKS(K+) + Tilt method
7 He,12 B,28 Al
Λ
Λ
Λ
~ 500 [keV] (FWHM)
Establish
exp. method
2009年
Medium heavy
3rd generation exp. JLab E05-115
HES(e’) + HKS(K+) + Tilt method
7 He,9 Li,10 Be, 12 B,52 V
Λ
Λ
Λ
Λ
Λ
≤ 500 [keV] (FWHM)
APFB2011 in Korea (T.Gogami)
45
JLab E05-115 experiment
APFB2011 in Korea (T.Gogami)
46
E05-115 experimental motivation (1)
12
• p-shell(7ΛHe , Λ9Li , 10
Λ Be , Λ B)
 Charge symmetry breaking
(CSB)
 ΛN-ΣN coupling
• Medium heavy (52V)
Λ
 s-,p-,d-,f-orbit binding energy
& cross section
 Mass dependence of Λ single
particle energy
 l・s splitting , core configuration
mixing
 dΛ, fΛ –state
It is difficult experimentally.
“ b.g. electron due to brems. ∝ ~Z2 “
BΛ [MeV]
•2009 Aug – Nov @ JLab Hall-C
•(e,e’K+) reaction
First try
•Target : 7Li , 9Be , 10B , 12C , 52Cr
APFB2011 in Korea (T.Gogami)
A = 52
47
JLab E05-115 experimental setup
e + p → e’ + Λ + K+
2×10-4
7 [msr]
3 – 12 [deg]
7Li
2×10-4
11 [msr]
2 – 12 [deg]
, 9Be , 10B , 12C , 52Cr
APFB2011 in Korea (T.Gogami)
48
JLab E05-115 experimental setup
e + p → e’ + Λ + K+
2×10-4
7 [msr]
3 – 12 [deg]
7Li
2×10-4
11 [msr]
2 – 12 [deg]
, 9Be , 10B , 12C , 52Cr
APFB2011 in Korea (T.Gogami)
49
HKS detectors
June 2009 in JLab Hall-C
1 [m]
HKS trigger
•CP = 1X ×1Y × 2X
•K = WC × AC
 CP × K
−
~18 [kHz]
(8 [μA] on 52Cr)
p
K+
π+
K+
p, π+
Cherenkov detectors -AC,WC• Aerogel (n=1.05)
• Water (n=1.33)
TOF walls -2X,1Y,1X(Plastic scintillators)
TOF σ
APFB2011 in Korea (T.Gogami)
≈ 170 [ps]
Drift chambers
-KDC1,KDC2σ ≈ 200 [μm]
50
HES Detectors
HES D magnet
Drift chambers
- EDC1 , EDC2 TOF walls - EH1 , EH2 (Plastic scintillators)
σ ~ 300 [ps]
Time Of Flight
HES trigger
EH1 × EH2
e
~2 [MHz]
(8 [μA] on 52Cr)
APFB2011 in Korea (T.Gogami)
51
Data Summary
JLab E05-115 (2009/June – 2009/Nov)
APFB2011 in Korea (T.Gogami)
52
Analysis process
HES
This talk
tracking
HKS
tracking
x , x’ , y , y’
at Reference plane
x , x’ , y , y’
at Reference plane
F2T function
F2T function
x’ , y’ , p
at Target
x’ , y’ , p
at Target
Missing Mass
particle ID
(select K+)
tune
tune
APFB2011 in Korea (T.Gogami)
53
Λ and
0
Σ
p(γ*,K+)Λ,Σ0
~40 hours
(5 shifts)
Because of high multiplicity of HKS
(analysis code cannot handle with high
APFB2011 in Korea (T.Gogami)
54
multiplicity)
Analysis for high multiplicity data
KDC2
KDC1
APFB2011 in Korea (T.Gogami)
55
Background event of HKS
9Be
Overhead view
x [cm]
y [cm]
, 38.4 [μA]
KDC1
Background events
Β≈1
KDC2
e- , e+
Events on HKS optics
KDC1
KDC2
z [cm]
HKS dipole magnet
NMR port
APFB2011 in Korea (T.Gogami)
SIMULATION
56
Singles rate summary
HKS
Up to ~30 [MHz]
HKS trigger
~ 10[kHz]
HES
COIN ≤ 2.0 [kHz]
Up to ~15 [MHz]
HES trigger
~ a few[MHz]
APFB2011 in Korea (T.Gogami)
57
Multiplicity of typical layer of chamber
HES
HKS
~1.13
~2.24
~4.94
~1.28
Multiplicity is high for HKS
APFB2011 in Korea (T.Gogami)
58
HKS drift chamber wire configuration
APFB2011 in Korea (T.Gogami)
59
Hit wires in KDC1
Overhead view
low
high
Overhead view
low
high
REAL DATA
Black : hit wires
Blue : selected wires
Red : track
CH2
REAL DATA
Black : hit wires
Blue : selected wires
Red : track
52Cr
Misidentification chance in hit wires selection increase !
APFB2011 in Korea (T.Gogami)
60
New tracking scheme
NEW
Good TDC
High multiplicity
Pattern recognition
• Hit wire selection with TOF
• 1X & 2X
• Grouping
• Pre-PID
• Cherenkov detectors
• 𝑑𝐸 𝑑𝑥
Reduce hit wires to analyze
Solve left right
Select good combination
Combination selection with TOF counters
Track fit
Reduce hit wire combinations
(h_tof_pre.f)
APFB2011 in Korea (T.Gogami)
61
DC hit info. selection with TOF
Gravity
CUT
~17%
CUT
Particle direction
~8%
Maximum gradient
Minimum gradient
Procedure in “h_dc_tofcut.f”
1. Get KTOF1X & 2X hit counter information
2. Make combination of 1X and 2X hit counter if those two are in
same group (grouping)
3. Determine cut conditions on KDC1 & KDC2
in Korea (T.Gogami)
4. Select Hit wires in KDCAPFB2011
and Reorder
them
62
Hit wires event display (1)
Gravity
• GREEN region
Selective region
• RED markers
Selected hit wires
• BLACK markers
Rejected hit wires
Particle direction
Seems to work well
APFB2011 in Korea (T.Gogami)
63
Apply to u,v-layer
v v’-layer
Selective region determined by
1X and 2X
Convert
x x’-layer
Applied to uu’ and vv’ layers , too.
APFB2011 in Korea (T.Gogami)
64
Hit wires event display (2)
v v’
u u’
v v’
u u’
particle
particle
x x’
x x’
• GREEN region
Selective region
• RED markers & lines Selected hit wires
• BLACK markers & lines Rejected hit wires
APFB2011 in Korea (T.Gogami)
65
Results of Introduction new code
Increased !
Increased !
Korea (T.Gogami)
ΛAPFB2011
c.s. in(CH
2/H2O) issue is solved
66
Rate dependences
• Why residuals get worse with rate (Multiplicity) ?
– Hardware ?
– Tracking is worse ?
– Parameters ?
APFB2011 in Korea (T.Gogami)
67
KTOF multiplicity
~2.7
~1.8
~6.5
~3.8
Multiplicity
of KDC are not only high52Cr , 77124
CH2 , 76314
but also TOF counters are! (for heavy target )
APFB2011 in Korea (T.Gogami)
68
Background event from NMR port
9Be
KDC1
These particles
come from
NMR port
KDC2
KDC1
KDC2
9Be
, 38.4 [μA]
KDC1
x [cm]
KDC2
Overhead view
y [cm]
KDC1
KDC2
Side view
9Be
HKS dipole magnet
, 38.4 [μA]
z [cm]
, 38.4 [μA]
Background events
Β≈1
e- , e+
NMR port
Events on HKS optics
APFB2011 in Korea (T.Gogami)
69
B.G. mix rate (real data)
b
a
B.G mix rate =
* hks ntulpe
APFB2011 in Korea (T.Gogami)
𝑏
𝑎+𝑏
70
e+ simulation
SIMULATION
• To see
1. Number of event
2. Angle & momentum
of e+ generated in target
APFB2011 in Korea (T.Gogami)
71
Target thickness dependence
(Simulation)
SIMULATION
52Cr
H2O
9Be
12C
CH2
10B
7Li
Consistent with B.G. mix rate !
APFB2011 in Korea (T.Gogami)
72
Angle and momentum distribution
of positrons
SIMULATION
Generate these
event in HKS GEANT
(Next page)
HKS cannot accept positrons directly !
APFB2011 in Korea (T.Gogami)
73
e , e+ background
in GEANT simulation
e+ generated in target make HKS dirty
Number of
e+
Correlation
(Simulation)
KDC1
B.G. mix rate (Real data)
KDC2
e- , e +
Vacuum chamber
(sus304)
NMR port
(sus304)
• Generated particle : e+
• Distribution : spherical uniform
• Momentum : 860 – 1000 [MeV/c]
• Angle : 0 – 2 [mrad]
APFB2011 in Korea (T.Gogami)
74
• 1000 events
Basic tracking procedure
Real data
52
CHCr2 target
Good TDC
High multiplicity
Pattern recognition
KDC1
Black : hit wires
Blue : selected wires
Red : track
Solve left right
Select good combination
Combination selection with TOF counters
Track fit
Reduce hit wire combinations
(h_tof_pre.f)
APFB2011 in Korea (T.Gogami)
75
Results of TOF cut with grouping
Residual
CH2 , 2.0 [μA] , 76315
σ ≈ 150 [μm]
Same
σ ≈ 150 [μm]
Multiplicity
CH2 , 2.0 [μA] , 76315
Shift
x x’
x x’
~1.2
~2.3
APFB2011 in Korea (T.Gogami)
76
Result of TOF cut with grouping
Original code
KDC
select
With “h_dc_tofcut.f”
allowance
Pure Selective region
allowance
𝑆2
𝐹𝑂𝑀 =
𝑁
Optimal allowance
𝐹𝑂𝑀𝑡𝑜𝑓𝑐𝑢𝑡
𝑁𝐹𝑂𝑀 =
𝐹𝑂𝑀𝑜𝑟𝑖𝑔𝑖𝑛𝑎𝑙
Number of K+ ~2[%] up
Too strict
Good tracks hid by background appear !
APFB2011 in Korea (T.Gogami)
77
Apply to u,v-layer
v v’-layer
Selective region determined by
1X and 2X
Convert
x x’-layer
Applied to uu’ and vv’ layers , too.
APFB2011 in Korea (T.Gogami)
78
Results of TOF cut with grouping (all layers)
Residual
σ ≈ 150 [μm]
CH2 , 2.0 [μA] , 76315
σ ≈ 150 [μm]
Same
Multiplicity
Multiplicity of uu’vv’-layers
• CH2
• ~20% reduction
•
52Cr
• ~5-10% reduction
APFB2011 in Korea (T.Gogami)
79
Results of TOF cut with grouping (all layers)
Faster !
Increase !
TOF cut works well
Faster !
52Cr
Increase !
APFB2011 in Korea (T.Gogami)
Parameters ?
80
Gogami’s study for other targets
Target
S (before)
S (after)
N(before)
N (after)
12C
(20mA)
7812
7840 (+0.4%)
6399
6429 (+0.5%)
12C
(35mA)
18016
19130 (+6.2%)
35854
38374 (+7.0%)
7Li
29009
35771(+23.3%)
55737
72609 (+30.2%)
10B
27811
27964(+0.5%)
21236
22000(+3.5%)
52Cr
1206
2958(+145.3%)
4902
11878(+142.3%)
APFB2011 in Korea (T.Gogami)
81
Coincidence time vs. Mass square
APFB2011 in Korea (T.Gogami)
82
Cherenkov cut
APFB2011 in Korea (T.Gogami)
83
Cherenkov light
APFB2011 in Korea (T.Gogami)
84
p(γ*,K+)Λ/Σ0 cross section
Comparison of CH2 and H2O
CH2
H2O
Λ [nb/sr]
50 (syst)
530 ± 50(stat) +- 20
40 (syst)
280 ± 40(stat) + -0
Σ0 [nb/sr]
120 ± 30(stat) -+10
10 (syst)
70 ± 20(stat) +10
- 0 (syst)
Λ/Σ0 ratio
530/120 ~ 4
280/70 = 4
Correction factors :
• AC cut ~ 0.89
• WC cut ~ 0.94
• HKS tracking ~ 0.99
• Mass2 cut ~ 0.99
• Kaon decay factor ~ 0.25
• (HES tracking ~ 0.9)
• EHODO inefficiency
• Lambda decrease ~ 0.84
Difference between CH2 and H2O
HKS analysis: almost consistent
→ • Coincidence time
• HES analysis efficiency
• # of virtual photon
• Accidental kill by AC
• Detectors' cut efficiency
→ Need to estimate these factors precisely
APFB2011 in Korea (T.Gogami)
85
After Gogami’s study
Doi
CH2
H2O
H2O/CH2
G/K
CH2
H2O
H2O/CH2
Λ
3880
410
0.11
Λ
5113
1002
0.20
Σ0
910
100
0.11
Σ0
1342
131
0.10
CH2
H2O
H2O (expected)
Λ [nb/sr]
530
280
280*0.20/0.11~510
Σ0 [nb/sr]
120
70
70*0.10/0.11~60
Λ/Σ0 ratio
530/120 ~ 4
280/70 = 4
(assume the  cross section in CH2 is
consistent for both analysis)
←Fitting of S has problem?
need more study
APFB2011 in Korea (T.Gogami)
86
Basic image of matrix tuning
procedure
1 loop
2 loop
st
nd
Tuning w/ , S
Initial : G4
100 times iteration
Obtain 100 12B
(20uA run) spectrums
-> Fit the 100 gs peaks
with gaussian
-> Select the finest peak
Tuning w/ , S, 12Bgs
Initial : Result of 1st loop
100 times iteration
Obtain 100 12B
(35uA run) spectrums
-> Fit the 100 gs peaks
with gaussian
-> Select the finest peak
・・
・ ・ ・ ・・・
Tuning w/ , S, 12Bgs
Initial : Result of 2st loop
100 times iteration
Obtain 100 12B
(35uA run) spectrums
-> Fit the 100 gs peaks
with gaussian
-> Select the finest peak
・・
・ ・ ・ ・・・
・・
3rd loop
・・
・ ・ ・ ・・・
・・
APFB2011 in Korea (T.Gogami)
・・
87
In the loop
How to select peaks?
• How to decide the cut region? 1s? 2s?
• How about the fitting?
Initial matrices
select peak
How to decide the c2?
• weight
• asymmetric c2?
(, S0, 12Bgs)
calculate
MM
iterate
n times
Mimimize c2
obtain new
matrices
APFB2011 in Korea (T.Gogami)
New matrices
(n sets)
88
before before/after Column,
after
SSColumn,
tune
(HKS)
Row, before
Row, after
APFB2011 in Korea (T.Gogami)
89
y’ vs x’ (before
tune)
vs xss (before tune)
The
effect
of SS tuneyss(HKS)
y’ vs x’ (after tune)
yss vs xss (after tune)
Need more tune?
APFB2011 in Korea (T.Gogami)
90
第一世代実験E89-009（2000年）
•
スペクトロメータの構成
splitter+SOS+Enge
• 測定した主なハイパー核
12 B
Λ
• エネルギー分解能
~750[keV](FWHM)
(当時最高)
(e,e‘K+)反応を用いたハイパー核分光
実験が可能であることを証明した
APFB2011 in Korea (T.Gogami)
91
第二世代実験E01-011(2005年)
•
スペクトロメータの構成
splitter+Enge+HKS
• 測定した主なハイパー核
7 He,12 B,28 Al
Λ
Λ
Λ
• エネルギー分解能
~400[keV](FWHM)
技術の確立
HKS建設エネルギー分解能向上
Tilt
法の導入
S/Nを劇的に改善 92
APFB2011
in Korea
(T.Gogami)
APFB2011 in Korea (T.Gogami)
93
Expected Missing mass of 52ΛV
APFB2011 in Korea (T.Gogami)
94
Typical Trigger Rate
APFB2011 in Korea (T.Gogami)
95
HKS Rate summary
target
current
Kaon
Pion
Proton
[μA]
[Hz]
[kHz]
[kHz]
CH2
2.0
82.3
6.7
7.1
7
31.6
325
27.2
37.1
37.9
269
23.4
31.7
38.2
152
11.8
15.0
19.3
125
9.1
11.1
7.3
34.2
4.6
3.4
Li
9
Be
10
B
12
C
52
Cr
APFB2011 in Korea (T.Gogami)
96
Data summary E05-115 ( 2009 Aug – Nov )
Physics
Data
Target hypernucleus thickness
beam
total
number of
expected
[mg/cm2] current[μA] charge[C] QF Λ (online) number of g.s.
7Li
7He
9Be
Λ Li
10B
10Be
12C
Λ
52Cr
Λ
Target
184.0
32.0
4.84
6.4E+4
(1.0 μb/sr)
~1000
(20 nb/sr)
188.1
38.3
5.33
4.5E+4
(1.2 μb/sr)
~200
(5 nb/sr)
56.1
38.7
6.25
4.8E+4
(1.3 μb/sr)
~800
(20 nb/sr)
12B
112.5
26.8
5.90
3.4E+4
(1.5 μb/sr)
~2000
(100 nb/sr)
52V
134.0
154.0
7.6
0.83
5.53
8.0E+3
(4.7 μb/sr)
~100
(70 nb/sr)
Λ
9
Λ
Calibration
Data
hypernucleus thickness
beam
total
[mg/cm2] current[μA] charge[C]
CH2
Λ , Σ0
450.8
H2O
Λ , Σ0
~500.0
2.0
0.28
2.7
0.20
APFB2011
in Korea (T.Gogami)
measured
assumption
97
E01-011
APFB2011 in Korea (T.Gogami)
98
 and S spectra (CH2 target)

E01-011
~70 hours
(450 mg/cm2, 1.5 uA)
1.9 MeV
(FWHM)
S
c.f. E89-009, 183 hours
(8.8 mg/cm2, 0.5 or 1.0 uA)
T. Miyoshi et al.,
Phy. Rev. Lett. 90, 232502(2003)
2.3 MeV
(FWHM)
~ 3.5 MeV
(FWHM)
Better resolution and statistics
APFB2011 in Korea (T.Gogami)
99
Background subtraction
Accidental background : polynomial function
APFB2011 in Korea (T.Gogami)
100
GEANT4
12C 100 mg/cm2
Effect of simple
gaussian fit:
= +20 keV
count difference : -30 %
APFB2011 in Korea (T.Gogami)
101
12C(e,e’K+)12
#1
#2
B
Two major peaks
#1 : [(p3/2)-1p,(s1/2)]
#2 : [(p3/2)-1p,(p3/2,p1/2)]
Resolution : ~470 keV (FWHM) for g.s.
Data taking : ~30 hours w/ 30 mA
(126)
(130)
Fitting Result
APFB2011 in Korea (T.Gogami)
102
12C(e,e’K+)12
#1
12C(+,K+)12 C
B,


#2
APFB2011 in Korea (T.Gogami)
103
12C(e,e’K+)12
#1
B
#2
APFB2011 in Korea (T.Gogami)
104
12C(e,e’K+)12
B
Red : calculation with SLA
Green : calculation with KMAID
#2
#1
Result
Theory by Sotona et. al.
(1.3 < E < 1.6 GeV, 1 < qK < 13 deg.)
J
Ex
[MeV]
Cross section [nb/sr]
SLA
KMAID
12-
0
0.14
19.7
65.7
20.7
43.0
2+
3+
10.99
11.06
48.3
75.3
38.0
68.5
ID
Ex
[MeV]
Cross section
[nb/sr]
Cross section
(Calc., SLA) [nb/sr]
#1
0
97±3.9 (stat.)
+29,-22 (sys.)
85.4
(1- + 2-)
(126)
123.6
(2+ + 3+)
(130)
#2
11.18±0.01 (stat.)
100±3.8 (stat.)
(sys.)
±0.10 (sys.) APFB2011 in+30,
Korea-30
(T.Gogami)
105
12C(e,e’K+)12
B
• Two major peaks ; #1:[(p3/2)-1p,(s1/2)],
#2:[(p3/2)-1p,(p3/2,p1/2)]
– Consistent -B with previous exp.
– Different width for g.s. with E94-107 data
– Ex and cross sections : agree with shell model
calculation
• Best resolution of 470 keV (FWHM) for g.s.
APFB2011 in Korea (T.Gogami)
106
28Si(e,e’K+)28
#1
#2
#3
Al
First sd-shell hypernuclear
spectroscopy by (e,e’K+)
Three major peaks
#1 : [(d5/2)-1p,(s1/2)]
#2 : [(d5/2)-1p,(p3/2,p1/2)]
#3 : [(d5/2)-1p,(d5/2,d3/2)]
Resolution : ~450 keV (FWHM) for g.s.
Data taking : ~30 hours w/ 30 mA
Fitting
Result
APFB2011 in Korea (T.Gogami)
(78)
(122)
107(77)
Shell model calculation
Full space
(0d5/20d3/21s1/2)pn11,12
DWIA
YNG interaction
APFB2011 in Korea (T.Gogami)
108
28Si(e,e’K+)28
28Si(+,K+)28 Si
Al,


#1 #2 #3
APFB2011 in Korea (T.Gogami)
109
28Si(e,e’K+)28
Al
Red : calculation with SLA
Green : calculation with KMAID
#1
Result
#2
#3
Theory by Sotona et. al.
(1.3 < E < 1.6 GeV, 1 < qK < 13 deg.)
J
Ex
[MeV]
Cross section [nb/sr]
SLA
KMAID
2+,3+
0
92.1
71.76
43-
9.42
9.67
134.9
91.3
117.5
58.5
4+
5+
17.6
17.9
148.4
139.1
135.1
89.9
ID
Ex
[MeV]
Cross section [nb/sr]
Cross section
(Calc. SLA) )[nb/sr]
#1
0
60±5.0 (stat.)
+27, -18 (sys.)
92.1
(2+ + 3+)
(78)
#2
10.98±0.02 (stat.)
±0.30 (sys.)
94±6.0 (stat.)
+43, -28 (sys.)
226.2
(4- + 3-)
(122)
#3
19.30±0.03 (stat.)
59±6.7 (stat.)
APFB2011 in Korea (T.Gogami)
+55, -18(sys.)
±0.30 (sys.)
287.5
(4+ + 5+)
110(77)
28Si(e,e’K+)28
Al
• First sd-shell hypernuclear spectroscopy
by (e,e’K+)
• Three major peaks ; #1:[(d5/2)-1p,(s1/2)],
#2:[(d5/2)-1p,(p3/2,p1/2)]
#3:[(d5/2)-1p,(d5/2,d3/2)]
–
–
–
–
Deeper -B for g.s. than 28Si and shell model calculation
Wider energy spacing between #1 and #2 than calc.
Narrower energy spacing between #2 and #3 than calc.
Smaller cross sections than calc.
APFB2011 in Korea (T.Gogami)
111
7Li(e,e’K+)7
Observation of 7He w/ good statistics
He
#1
Fitting Result
(40)
APFB2011 in Korea (T.Gogami)
112
CSB effect by cluster model
E.Hiyama et al.
PRC80,054321(2009)
Four-body cluster model


N
N
Phenomenological potential
-B= -5.36 w/o CSB
APFB2011 in Korea (T.Gogami)-5.16 w/ CSB
113
7Li(e,e’K+)7
He
Result
ID
-B
[MeV]
Cross section
[nb/sr]
#1
-5.71±0.02 (stat.)
±0.20 (sys.)
31±2.8 (stat.)
+11.8,-9.3 (sys.)
(40)
#1
Theory by Sotona et. al. (Cross section)
by Hiyama et. al. ( -B : w/o CSB)
(1.3 < E < 1.6 GeV, 1 < qK < 13 deg.)
J
Red : calculation with SLA
Green : calculation with KMAID
1/2+
APFB2011 in Korea (T.Gogami)
-B
[MeV]
-5.36
Cross section [nb/sr]
SLA
KMAID
13.2
9.7
114
7Li(e,e’K+)7
He
• High statistics spectroscopy
• -B=-5.71±0.02 (stat.)±0.20 (sys.) for g.s.
– Cluster model calculation
-B=-5.36 (w/o CSB)
-B=-5.16 (w/ CSB)
• Cross section : larger than shell model calc.
APFB2011 in Korea (T.Gogami)
115
E01-011 ~Count, S/N~
Peak ID
7
He:#1
# of peak
[counts]
# of BG(3s)
[counts]
S/N
Sys. Err.
(Contami. -%)
Sys. Err.
(Loss +%)
120
230
0.52
30
30
12
B:#1
630
561
1.12
5
30
12
B:#2
695
706
0.98
20
30
28
Al:#1
145
360
0.40
40
30
28
Al:#2
240
516
0.47
40
30
28
Al:#3
77
545
0.14
90
30
APFB2011 in Korea (T.Gogami)
116
APFB2011 in Korea (T.Gogami)
117