HLAB meeting
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Transcript of HLAB meeting
HLAB meetingStatus ReportToshi 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 & Mainze + p ➝ e’ + K+ + Λ
Spectroscopic experiment by (e,e’K+) reaction
pn
γ*
ΛK+
e-
e + p ➝ e’ + K+ + Λe e
target nucleus
Feynman diagram
uud
ussud
–p K+
Λ
γ*
e’-Spectrometer
K+-Spectrometer
pe’
pK+
Coincidence Missing Mass HHY
Experimental setup of JLab E05-115
Splitter Magnet
HKS
HES e’
K+
p(e,e’K+)Λ,(Σ0)
Experimental setup of JLab E05-115
2×10-4
7 [msr]3 – 12 [deg] 2×10-4
8.5 [msr]2 – 12 [deg]
7Li , 9Be , 10B , 12C , 52Cr
p(e,e’K+)Λ
( 7ΛHe , 9
ΛLi , 10ΛBe , 12
ΛB , 52ΛV ) 2 - 50 [μA]
10 - 300 [THz]
Tracking
Data taking : Aug-Nov 2009
CH2, H2O
Discrepancy of Number of Λ
Lost events that we are interested in in tracking procedure.ECT*/JSPS core to core, T.Gogami (2011) 7
Black : hit wires Blue : selected wiresRed : track
Black : hit wires Blue : selected wiresRed : track
REAL DATA REAL DATA
Λ Λ
Σ0Σ0
CH2 Target H2O Target
The number of ΛNΛ ¼ Nexpect
12C quasi-free
Acc. b.g.
16O quasi-freeAcc. b.g.
The number of ΛNΛ Nexpect
Very preliminary
Very preliminary
New tracking code
Results of Introduction of new Tracking Code
Increased !
Increased !
CH2
52Cr
•NΛ ¼ Nexpect
NΛ ½ NexpectH2O
For further improvement
• Efficiency– Tracking– TOF detectors
• Discarded events
Rates of the KDC wires52Cr, 77124
Wire Number
Rate
[kHz
]KDC1-u KDC1-u’ KDC1-x KDC1-x’ KDC1-v KDC1-v’
KDC2-u KDC2-u’ KDC2-x KDC2-x’ KDC2-v KDC2-v’
< 510 kHz < 350 kHz
< 290 kHz < 230 kHz
52Cr, 77124
KDC1 KDC2~11 MHz~22 MHz
77124 ( 52Cr target )
5 × 5
Rates of the HKS TOF detectors
Events which are discarded
52Cr, 77124
KDC1
KDC2
Events which are discarded
52Cr, 77124
KDC1
KDC2
• Where and why are these events discarded ?• Are these events threw away by correct cut condition?
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
12C -
Weak mesonic two body decay
1- 0.02- ~150 keV
Ground state doublet of 12
BB and
Direct Production
p
e’
e12C K
+
Example:
Hypernuclear States:s (or p) coupled to low lying core nucleus
12Bg.s.
E.M.
*
12B
Decay Pion Spectroscopy for Light and Exotic -Hypernuclei
Fragmentation Process
p
e’
e 12C
Example: K +
*
s12B*
Highly Excited Hypernuclear States:s coupled to High-Lying core nucleus, i.e.particle hole at s orbit
4H
Fragmentation (<10-16s)
4Hg.s.
4He
-
Weak mesonic two body decay (~10-10s)
Access to variety of light and exotic hypernuclei,
some of which cannot be produced or measured
precisely by other means
Spectroscopic experiment by (e,e’K+) reaction
pn
γ*
ΛK+
e-
e + p ➝ e’ + K+ + Λe e
target nucleus
Feynman diagram
uud
ussud
–p K+
Λ
γ*
1. Large Momentum transfer• Λ can be bounded in deeper orbit
2. Λ’s spin at forward angle• Spin flip ~ spin non-flip
3. Proton Λ,Σ0
• Absolute mass scale calibration
e’-Spectrometer
K+-Spectrometer
pe’
pK+
Coincidence Missing Mass HHY
JLab E05-115 experimental setup
2×10-4
7 [msr]3 – 12 [deg]
2×10-4
8.5 [msr]2 – 12 [deg]
e + p → e’ + Λ + K+
7Li , 9Be , 10B , 12C , 52Cr
• (e,e’K+) experiment 1. Coincidence experiment (K+ and e-)2. Small cross section ( ~100 [nb/sr] ) 1/10003. Energy resolution Sub MeV (FWHM)
Primary beam• High intensity
Thin target (~100 [mg/cm2])• High quality
APFB2011 in Korea (T.Gogami) 21
Experimental setup of JLab E05-115
2×10-4
7 [msr]3 – 12 [deg] 2×10-4
8.5 [msr]2 – 12 [deg]
7Li , 9Be , 10B , 12C , 52Cr
p(e,e’K+)Λ
( 7ΛHe , 9
ΛLi , 10ΛBe , 12
ΛB , 52ΛV ) 2 - 50 [μA]
10 - 300 [THz]
Tracking
Data taking : Aug-Nov 2009
HKS chamber wire configuration
CH2, H2O
HKS Drift Chamber hit selectionwith TOF detectors
• GREEN regionSelective region
• RED markersSelected hit wires
• BLACK markersRejected hit wires
Particle direction
Gravity
Results of Introduction of new Tracking Code
Increased !
Increased !
CH2
52Cr
•NΛ ¼ Nexpect
NΛ ½ NexpectH2O
Theoretical calculation of A=7 system
-B (MeV)
-6.650.03 0.2 MeV from α n n
JLab E01-0117Li(e,e’K+)7
ΛHe
Four-body cluster model for T=1 triplet hypernuclei(E.Hiyama et al., NPC 80, 2009)α + Λ + N + N
CSB interaction is determined to reproduce BΛ of 4
ΛH and 4ΛHe.
Preliminary
APFB2011 in Korea (T.Gogami) 25
(e,e’K+) experiment in JLab Hall-C2000
1st generation exp. JLab E89-009ENGE(e’) + SOS(K+)
12ΛB
~ 750 [keV] (FWHM)
2005 2nd generation exp. JLab E01-011ENGE(e’) + HKS(K+) + Tilt method
7ΛHe,12
ΛB,28ΛAl
~ 500 [keV] (FWHM)
2009 3rd generation exp. JLab E05-115HES(e’) + HKS(K+) + Tilt method
7ΛHe,9
ΛLi,10ΛBe, 12
ΛB,52ΛV
≤ 500 [keV] (FWHM)
Proof of feasibility
Establish exp. method
Up to Medium heavy
12C(e,e’K+)12ΛB
E89-009
Preliminary
sΛpΛ
~750 [keV] (FWHM)
Confirming stage
Analysis stage
sΛpΛ dΛ
28Si(e,e’K+)28ΛAl
E01-011
~600 [keV] (FWHM)
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(e,e’K+) experiment in JLab Hall-A
2007 JLab E94-107
HRS’s (K+, e+)+ septum9
ΛLi,12ΛB,16
ΛN~ 670 [keV] (FWHM) 16O(e,e’K+)16
ΛN
12C(e,e’K+)12ΛB
sΛ pΛ
sΛ
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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
Tilt 法の概略図 第一世代 第二世代 200 [MHz] 1 [MHz]
e’ rateAPFB2011 in Korea (T.Gogami) 28
Tilt 角の最適化• 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
Figure of Merit (FoM)
Target e’ rate [kHz]10B 48012C 55852Cr 1780
6.5o
ビーム強度 30 [μA] , 100 [mg/cm2] を仮定
シミュレーションによる計数率の見積もり
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角度アクセプタンス
ハイパー核の収量が増加
第二世代実験 E01-011
第三世代実験 E05-115
入射電子ビームのエネルギー1.851 2.344 [GeV]
•HES の角度アクセプタンスが広い
•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
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運動量アクセプタンス Ei=2.344,ω=1.5[GeV]
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。
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
HKS と HES の運度量の相関
52ΛV g.s.
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89Y(π+,K+)89ΛY, 51V(π+,K+)51
ΛV
89Y(π+,K+)89ΛY 51V(π+,K+)51
ΛV 12C(π+,K+)12ΛC
1.45 [MeV] (FWHM)KEK-PS E36989Y(π+,K+)89
ΛYKEK-PS E36951V(π+,K+)51
ΛV KEK-PS E36912C(π+,K+)12
ΛC
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E05-115 experimental motivation(2)
APFB2011 in Korea (T.Gogami)
s
p d f
Photo- and electro production of medium mass Λ-hypernuclei ,P.Bydzovsky et al. (2008)
FULL(8)1f7/2
1d3/2FULL(4) FULL(4)・・・・・・sn = 28 p = 24p
d
f
4-
5+
6-
7+
3-
4+
5-
6+
Λ52ΛV
52Cr
or
or
or
or
ls splitting 2l+1∝
• ls splitting • Core excited
33
Spectroscopic experiment via (e,e’K+) reaction
pn
γ*
ΛK+
e-
e + p ➝ e’ + K+ + Λe e
M2HY = (Ee + MT - EK+ - Ee’)2 - ( pe - pK+ - pe’)2
measuretarget nucleus
Feynman diagram
uud
ussud
–p K+
Λ
γ*
Missing mass :
•Binding energy•Cross section
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P.Bydzovsdy ,photo- and electro production of medium mass Λ-hypernuclei, 2008
APFB2011 in Korea (T.Gogami) 35
Λ single particle energy
D.J.Millener et al. PRC 38, 6, 1988Woods-Saxson potential with a depth of 28 [MeV] and a radius parameter
(e,e’K+) experiments in JLab• E89-009 (2000)• E94-107 (2004)• E01-011 (2005)• E05-115 (2009)
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Feature of (e,e’K+) reaction
uud
ussud
e e
–p K+
Λ
γ*
ud
ddu
us
sdu
– –π+
Λn
us
ddu
ud
sdu
–K-
Λn
–π-
e + p ➝ e + K+ + Λ π+ + n ➝ K+ + Λ
K+
K- + n ➝ π- + Λ(π+ , K+) (K- , π-)(e,e’K+)
Momentum transfer(Typical )
~300 [MeV/c] ~300 [MeV/c] ~90 [MeV/c]
Λ’s SpinAt forward angle
Λ’s from proton neutron neutron
flip ≈ non-flip non-flip non-flip
Beam primary secondary secondary
Target Thin (~100 mg/cm2)(Isotopically enriched) Thick(> a few [g/cm2] ) Thick(> a few [g/cm2] )
Reaction
Λ can be bounded in deeper orbit
Spin dependent structure
Mirror lambda hypernuclei
High quality , high intensity
Fine structureEnergy resolution
(FWHM)≤ 500 [keV] 1 – 3 [MeV] 1 – 3 [MeV]APFB2011 in Korea (T.Gogami) 37
Theoretical calculation of A=7 system
-B (MeV)
-6.650.03 0.2 MeV from α n n
JLab E01-0117Li(e,e’K+)7
ΛHe
Four-body cluster model for T=1 triplet hypernuclei(E.Hiyama et al., NPC 80, 2009)α + Λ + N + N
CSB interaction is determined to reproduce BΛ of 4
ΛH and 4ΛHe.
Preliminary
APFB2011 in Korea (T.Gogami) 38
(e,e’K+) experiment in JLab Hall-C2000
1st generation exp. JLab E89-009ENGE(e’) + SOS(K+)
12ΛB
~ 750 [keV] (FWHM)
2005 2nd generation exp. JLab E01-011ENGE(e’) + HKS(K+) + Tilt method
7ΛHe,12
ΛB,28ΛAl
~ 500 [keV] (FWHM)
2009 3rd generation exp. JLab E05-115HES(e’) + HKS(K+) + Tilt method
7ΛHe,9
ΛLi,10ΛBe, 12
ΛB,52ΛV
≤ 500 [keV] (FWHM)
Proof of feasibility
Establish exp. method
Up to Medium heavy
12C(e,e’K+)12ΛB
E89-009
Preliminary
sΛpΛ
~750 [keV] (FWHM)
Confirming stage
Analysis stage
sΛpΛ dΛ
28Si(e,e’K+)28ΛAl
E01-011
~600 [keV] (FWHM)
APFB2011 in Korea (T.Gogami) 39
(e,e’K+) experiment in JLab Hall-A
2007 JLab E94-107
HRS’s (K+, e+)+ septum9
ΛLi,12ΛB,16
ΛN~ 670 [keV] (FWHM) 16O(e,e’K+)16
ΛN
12C(e,e’K+)12ΛB
sΛ pΛ
sΛ
APFB2011 in Korea (T.Gogami) 40
Elementary process p(e,e’K+)Λ
• p(e,e’K+)Λ,Σ0 are used for Energy calibration
• Study of elementary process
• Consistency check with past experiment
~40 hours(5 shifts)
JLab E05-115p(e,e’K+)Λ,Σ0
Very preliminary
R. Bradford et al. , FRC73, 2006APFB2011 in Korea (T.Gogami) 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– JLab, (Mainz Univ.)
• A=7 – 52• Resolution (FWHM) ~ 500 keV
Determine Absolute value
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(e,e’K+) reaction
uud
ussud
e e
–p K+
Λ
γ*
ud
ddu
us
sdu
– –π+
Λn
us
ddu
ud
sdu
–K-
Λn
–π-
e + p ➝ e + K+ + Λ π+ + n ➝ K+ + Λ
K+
K- + n ➝ π- + Λ(π+ , K+) (K- , π-)(e,e’K+)
Momentum transfer(Typical )
~300 [MeV/c] ~300 [MeV/c] ~90 [MeV/c]
Λ’s SpinAt forward angle
Λ’s from proton neutron neutron
flip ≈ non-flip non-flip non-flip
Beam primary secondary secondary
Target Thin (~100 mg/cm2)(Isotopically enriched) Thick(> a few [g/cm2] ) Thick(> a few [g/cm2] )
Reaction
Λ can be bounded in deeper orbit
Spin dependent structure
Mirror lambda hypernuclei
High quality , high intensity
Fine structureEnergy resolution
(FWHM)≤ 500 [keV] 1 – 3 [MeV] 1 – 3 [MeV]APFB2011 in Korea (T.Gogami) 43
APFB2011 in Korea (T.Gogami)
JLab CEBAF ( Continuance Electron Beam Accelerator Facility )
• (e,e’K+) experiment1. Coincidence experiment (K+ and e-)2. Small cross section ( ~100 [nb/sr] ) 1/10003. Energy resolution sub MeV (FWHM)
100 [m]
Maximum beam energy 6.0[GeV]
Maximum beam intensity 200[μA/Hall]
Beam emittance ~2 [mm ・ μrad]Beam energy spread <1×10-4
Beam bunch interval ~2[ns] (499[MHz])
• Requirement for accelerator1. high duty factor2. high intensity3. small emittance small ΔE/E
CEBAF can satisfythese requirements
Thomas Jefferson National Accelerator Facility
44
APFB2011 in Korea (T.Gogami)
(e,e’K+) experiment in JLab Hall-C2000 年
1st generation exp. JLab E89-009ENGE(e’) + SOS(K+)
12ΛB
~ 900 [keV] (FWHM)
2005 年 2nd generation exp. JLab E01-011ENGE(e’) + HKS(K+) + Tilt method
7ΛHe,12
ΛB,28ΛAl
~ 500 [keV] (FWHM)
2009 年 3rd generation exp. JLab E05-115HES(e’) + HKS(K+) + Tilt method
7ΛHe,9
ΛLi,10ΛBe, 12
ΛB,52ΛV
≤ 500 [keV] (FWHM)
Luminosity ×137e’ rate 1/200S/N ×2.7
Proof of feasibility
Establish exp. method
Medium heavy
45
JLab E05-115 experiment
APFB2011 in Korea (T.Gogami) 46
E05-115 experimental motivation (1)
• p-shell(7He , 9Li , 10Be , 12B) Charge symmetry breaking
(CSB) ΛN-ΣN coupling
•2009 Aug – Nov @ JLab Hall-C•(e,e’K+) reaction•Target : 7Li , 9Be , 10B , 12C , 52Cr
Λ Λ Λ Λ
First try
B Λ [M
eV]
It is difficult experimentally.“ b.g. electron due to brems. ~Z∝ 2 “
A = 52
• Medium heavy (52V) 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
Λ
APFB2011 in Korea (T.Gogami) 47
JLab E05-115 experimental setup
2×10-4
7 [msr]3 – 12 [deg] 2×10-4
11 [msr]2 – 12 [deg]
e + p → e’ + Λ + K+
7Li , 9Be , 10B , 12C , 52Cr
APFB2011 in Korea (T.Gogami) 48
JLab E05-115 experimental setup
2×10-4
7 [msr]3 – 12 [deg] 2×10-4
11 [msr]2 – 12 [deg]
e + p → e’ + Λ + K+
7Li , 9Be , 10B , 12C , 52Cr
APFB2011 in Korea (T.Gogami) 49
HKS detectors
K+
p, π+
Drift chambers-KDC1,KDC2-TOF walls -2X,1Y,1X-
(Plastic scintillators)
Cherenkov detectors -AC,WC-• Aerogel (n=1.05)• Water (n=1.33)
1 [m] June 2009 in JLab Hall-C
HKS trigger• CP = 1X ×1Y × 2X • K = WC × AC
CP × K
~18 [kHz](8 [μA] on 52Cr)
−π+
K+
p
σ ≈ 200 [μm]TOF σ ≈ 170 [ps]APFB2011 in Korea (T.Gogami) 50
APFB2011 in Korea (T.Gogami)
HES DetectorsDrift chambers- EDC1 , EDC2 -
TOF walls - EH1 , EH2 - (Plastic scintillators)
HES D magnet
HES triggerEH1 × EH2
~2 [MHz](8 [μA] on 52Cr)e
Time Of Flight
σ ~ 300 [ps]
51
Data Summary
JLab E05-115 (2009/June – 2009/Nov)
APFB2011 in Korea (T.Gogami) 52
Analysis process
trackingx , x’ , y , y’ at Reference plane
x’ , y’ , pat Target
Missing Mass
trackingx , x’ , y , y’ at Reference plane
x’ , y’ , pat Target
p : Λ , Σ0 ,12ΛB
Angle : Sieve slit
F2T functionF2T function
particle ID(select K+)
HKSHES
tune tune
This talk
APFB2011 in Korea (T.Gogami) 53
Λ and Σ0
Because of high multiplicity of HKS(analysis code cannot handle with high multiplicity)
~40 hours(5 shifts)
p(γ*,K+)Λ,Σ0
APFB2011 in Korea (T.Gogami) 54
Analysis for high multiplicity data
KDC1
KDC2
HKS event displayAPFB2011 in Korea (T.Gogami) 55
Background event of HKS
HKS dipole magnet
NMR port
z [cm]
y [cm]
x [cm] KDC1
KDC2
KDC1
KDC2
9Be , 38.4 [μA]Overhead view
Background events
Events on HKS optics
Β ≈ 1e- , e+
SIMULATIONAPFB2011 in Korea (T.Gogami) 56
Singles rate summaryUp to ~30 [MHz]
Up to ~15 [MHz]HES
HKS
HKS trigger ~ 10[kHz]
HES trigger ~ a few[MHz]
COIN 2.0 [kHz]
APFB2011 in Korea (T.Gogami) 57
Multiplicity of typical layer of chamberHES HKS
~1.13
~1.28
~2.24
~4.94
Multiplicity is high for HKS
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HKS drift chamber wire configuration
APFB2011 in Korea (T.Gogami) 59
Hit wires in KDC1
Overhead viewKDC1
Black : hit wires Blue : selected wiresRed : track
Black : hit wires Blue : selected wiresRed : track
CH2 52Cr
Misidentification chance in hit wires selection increase !
REAL DATA REAL DATA
low high low high
Overhead view
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New tracking scheme
Good TDC
Pattern recognition
Track fit
Solve left right
Select good combination
Combination selection with TOF counters
Reduce hit wire combinations (h_tof_pre.f)
High multiplicity
• Hit wire selection with TOF• 1X & 2X • Grouping
• Pre-PID• Cherenkov detectors
Reduce hit wires to analyze
NEW
APFB2011 in Korea (T.Gogami) 61
DC hit info. selection with TOF
Selective region Maximum gradient
Minimum gradient
Particle direction
Gravity
CUT~8%
~17%
Procedure in “h_dc_tofcut.f”1. Get KTOF1X & 2X hit counter information2. Make combination of 1X and 2X hit counter if those two are in
same group (grouping) 3. Determine cut conditions on KDC1 & KDC24. Select Hit wires in KDC and Reorder them
CUT
APFB2011 in Korea (T.Gogami) 62
Hit wires event display (1)
• GREEN regionSelective region
• RED markersSelected hit wires
• BLACK markersRejected hit wires
Seems to work well
Particle direction
Gravity
APFB2011 in Korea (T.Gogami) 63
Apply to u,v-layer
Applied to uu’ and vv’ layers , too.
Selective region determined by 1X and 2X
Convert
v v’-layer
x x’-layer
APFB2011 in Korea (T.Gogami) 64
Hit wires event display (2)
• GREEN region Selective region• RED markers & lines Selected hit wires• BLACK markers & lines Rejected hit wires
v v’ u u’
x x’
v v’ u u’
x x’
KDC1 KDC2particle particle
APFB2011 in Korea (T.Gogami) 65
Results of Introduction new code
Λ c.s. (CH2/H2O) issue is solved
Increased !
Increased !
CH2
52Cr
APFB2011 in Korea (T.Gogami) 66
Rate dependences
Quadratic dependence Linear dependence
• 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
CH2 , 76314 52Cr , 77124Multiplicity of KDC are not only high but also TOF counters are! (for heavy target )
APFB2011 in Korea (T.Gogami) 68
Background event from NMR port
z [cm]
y [cm]
x [cm]
These particles come from NMR port
HKS dipole magnet
NMR port
KDC1
KDC2
KDC1
KDC2
KDC1
KDC2
KDC1
KDC2
Background events
9Be , 38.4 [μA]
9Be , 38.4 [μA] 9Be , 38.4 [μA]
Events on HKS optics
Overhead view
Side view
Β ≈ 1e- , e+
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B.G. mix rate (real data)
ab
B.G mix rate =
* hks ntulpeAPFB2011 in Korea (T.Gogami) 70
e+ simulation
SIMULATION
• To see 1. Number of event2. Angle & momentum
of e+ generated in target
APFB2011 in Korea (T.Gogami) 71
Target thickness dependence(Simulation)
H2O52Cr9Be
12C CH2
10B
7Li
Consistent with B.G. mix rate !
SIMULATION
APFB2011 in Korea (T.Gogami) 72
Angle and momentum distribution of positrons
HKS cannot accept positrons directly !
Generate these event in HKS GEANT(Next page)
SIMULATION
APFB2011 in Korea (T.Gogami) 73
e , e+ background in GEANT simulation
Vacuum chamber(sus304)
NMR port(sus304)
KDC1 KDC2
e- , e+
• Generated particle : e+
• Distribution : spherical uniform• Momentum : 860 – 1000 [MeV/c]• Angle : 0 – 2 [mrad]• 1000 events
Number of e+ (Simulation) B.G. mix rate (Real data)Correlation
e+ generated in target make HKS dirty
APFB2011 in Korea (T.Gogami) 74
Basic tracking procedure
Good TDC
Pattern recognition
Track fit
Solve left right
Select good combination
Black : hit wires Blue : selected wiresRed : track
CH2 target
KDC1
52Cr target
Combination selection with TOF counters
Reduce hit wire combinations (h_tof_pre.f)
High multiplicity
Real data
APFB2011 in Korea (T.Gogami) 75
Results of TOF cut with grouping
CH2 , 2.0 [μA] , 76315
Shift
Same
Residual
Multiplicity
CH2 , 2.0 [μA] , 76315
σ 150 [μm] σ 150 [μm]
~2.3
~1.2
before after
x x’ x x’
APFB2011 in Korea (T.Gogami) 76
Result of TOF cut with groupingOriginal code
With “h_dc_tofcut.f”Pure Selective regionallowance
allowance
KDC
Too strict
select
Optimal allowance
Good tracks hid by background appear ! Number of K+ ~2[%] up
APFB2011 in Korea (T.Gogami) 77
Apply to u,v-layer
Applied to uu’ and vv’ layers , too.
Selective region determined by 1X and 2X
Convert
v v’-layer
x x’-layer
APFB2011 in Korea (T.Gogami) 78
Results of TOF cut with grouping (all layers)
Residual
Multiplicity
CH2 , 2.0 [μA] , 76315
σ 150 [μm] σ 150 [μm]
Multiplicity of uu’vv’-layers• CH2
• ~20% reduction• 52Cr
• ~5-10% reduction
Same
before after
APFB2011 in Korea (T.Gogami) 79
Results of TOF cut with grouping (all layers)
Faster !
Increase !TOF cut works well
52Cr
CH2
52CrFaster !
Increase !
Parameters ?APFB2011 in Korea (T.Gogami) 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
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
CH2 H2OΛ [nb/sr] 530 ± 50(stat) + 50 (syst) 280 ± 40(stat) + 40 (syst)Σ0 [nb/sr] 120 ± 30(stat) +10 (syst) 70 ± 20(stat) +10 (syst)
Λ/Σ0 ratio 530/120 ~ 4 280/70 = 4
- 20
- 10
-0
- 0
Comparison of CH2 and H2O
Difference between CH2 and H2O
• Coincidence time• HES analysis efficiency• # of virtual photon• Accidental kill by AC• Detectors' cut efficiency
→ Need to estimate these factors precisely
HKS analysis: almost consistent
→
APFB2011 in Korea (T.Gogami) 85
After Gogami’s studyDoi CH2 H2O H2O/CH2
Λ 3880 410 0.11Σ0 910 100 0.11
G/K CH2 H2O H2O/CH2
Λ 5113 1002 0.20Σ0 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 procedure1st loop 2nd loop 3rd loop
Tuning w/ , SInitial : G4100 times iteration
Tuning w/ , S, 12Bgs
Initial : Result of 1st loop100 times iteration
Tuning w/ , S, 12Bgs
Initial : Result of 2st loop100 times iteration
Obtain 100 12B
(20uA run) spectrums-> Fit the 100 gs peaks with gaussian-> Select the finest peak
Obtain 100 12B
(35uA run) spectrums-> Fit the 100 gs peaks with gaussian-> Select the finest peak
Obtain 100 12B
(35uA run) spectrums-> Fit the 100 gs peaks with gaussian-> Select the finest peak
・・・ ・ ・ ・・・・・・・・・・ ・ ・ ・・・ ・・
・・・ ・ ・ ・・・
Use as next initial Use as next initial
APFB2011 in Korea (T.Gogami) 87
In the loop
select peak(, S0, 12
Bgs)
Mimimize c2
obtain new matrices
calculate MM
Initial matrices
iterate n times
New matrices(n sets)
How to select peaks?• How to decide the cut region? 1s? 2s?• How about the fitting?
How to decide the c2?• weight• asymmetric c2?
APFB2011 in Korea (T.Gogami) 88
SS tune before/after (HKS)Column, before Column, after
Row, before Row, after
APFB2011 in Korea (T.Gogami) 89
The effect of SS tune (HKS)y’ vs x’ (before tune)
y’ vs x’ (after tune)
yss vs xss (before 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
ΛB• 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
• 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
ΛHe,12ΛB,28
ΛAl• エネルギー分解能 ~400[keV](FWHM)
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
第二世代実験 E01-011(2005年 )
技術の確立 APFB2011 in Korea (T.Gogami) 92
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
APFB2011 in Korea (T.Gogami) 96
バックグラウンドを含める ??
target current Kaon Pion Proton
[μA] [Hz] [kHz] [kHz]
CH2 2.0 82.3 6.7 7.1 7Li 31.6 325 27.2 37.1
9Be 37.9 269 23.4 31.7 10B 38.2 152 11.8 15.0 12C 19.3 125 9.1 11.1
52Cr 7.3 34.2 4.6 3.4
HKS Rate summary
Target hypernucleus thickness[mg/cm2]
beam current[μA]
total charge[C]
number of QF Λ (online)
expected number of
g.s.7Li 7He 184.0 32.0 4.84 6.4E+4
(1.0 μb/sr)~1000
(20 nb/sr)9Be 9Li 188.1 38.3 5.33 4.5E+4
(1.2 μb/sr)~200
(5 nb/sr)10B 10Be 56.1 38.7 6.25 4.8E+4
(1.3 μb/sr)~800
(20 nb/sr)12C 12B 112.5 26.8 5.90 3.4E+4
(1.5 μb/sr)~2000
(100 nb/sr)52Cr 52V 134.0
154.07.6 0.83
5.538.0E+3
(4.7 μb/sr)~100
(70 nb/sr)
Data summary
APFB2011 in Korea (T.Gogami)
Λ
Λ
Λ
Λ
Λ
E05-115 ( 2009 Aug – Nov )
measuredassumption
Target hypernucleus thickness[mg/cm2]
beam current[μA]
total charge[C]
CH2 Λ , Σ0 450.8 2.0 0.28
H2O Λ , Σ0 ~500.0 2.7 0.20
Physics Data
Calibration Data
97
E01-011
APFB2011 in Korea (T.Gogami) 98
and S spectra (CH2 target)
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)
Better resolution and statistics
~ 3.5 MeV (FWHM)
1.9 MeV (FWHM) S
2.3 MeV (FWHM)
E01-011 ~70 hours (450 mg/cm2, 1.5 uA)
APFB2011 in Korea (T.Gogami) 99
Background subtraction
Accidental background : polynomial functionAPFB2011 in Korea (T.Gogami) 100
GEANT412C 100 mg/cm2
Effect of simple gaussian fit:D= +20 keV
count difference : -30 %
APFB2011 in Korea (T.Gogami) 101
12C(e,e’K+)12B
Resolution : ~470 keV (FWHM) for g.s.Data taking : ~30 hours w/ 30 mA
Fitting Result
#1 #2
Two major peaks#1 : [(p3/2)-1
p,(s1/2)]#2 : [(p3/2)-1
p,(p3/2,p1/2)]
(126)(130)
APFB2011 in Korea (T.Gogami) 102
#1 #2
12C(e,e’K+)12B, 12C(+,K+)12
C
APFB2011 in Korea (T.Gogami) 103
12C(e,e’K+)12B
#1 #2
APFB2011 in Korea (T.Gogami) 104
12C(e,e’K+)12B
Red : calculation with SLAGreen : calculation with KMAID
Theory by Sotona et. al. (1.3 < E < 1.6 GeV, 1 < qK < 13 deg.)
Result
#1J Ex
[MeV]Cross section [nb/sr]
SLA KMAID
1-
2-
00.14
19.765.7
20.743.0
2+
3+
10.9911.06
48.375.3
38.068.5
#2
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-)
#2 11.18±0.01 (stat.) ±0.10 (sys.)
100±3.8 (stat.) +30, -30 (sys.)
123.6(2+ + 3+)
(126)
(130)APFB2011 in Korea (T.Gogami) 105
12C(e,e’K+)12B
• 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+)28Al
Resolution : ~450 keV (FWHM) for g.s.Data taking : ~30 hours w/ 30 mA
#1 #2#3
Fitting Result
Three major peaks#1 : [(d5/2)-1
p,(s1/2)]#2 : [(d5/2)-1
p,(p3/2,p1/2)]#3 : [(d5/2)-1
p,(d5/2,d3/2)]
First sd-shell hypernuclear spectroscopy by (e,e’K+)
(78)(122)(77)APFB2011 in Korea (T.Gogami) 107
Shell model calculation
Full space (0d5/20d3/21s1/2)pn
11,12
DWIAYNG interaction
APFB2011 in Korea (T.Gogami) 108
#1 #2 #3
28Si(e,e’K+)28Al, 28Si(+,K+)28
Si
APFB2011 in Korea (T.Gogami) 109
28Si(e,e’K+)28Al
Theory by Sotona et. al. (1.3 < E < 1.6 GeV, 1 < qK < 13 deg.)#1J Ex
[MeV]Cross section [nb/sr]
SLA KMAID
2+,3+ 0 92.1 71.76
4-
3-
9.429.67
134.991.3
117.558.5
4+
5+
17.617.9
148.4139.1
135.189.9
#2#3
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+)
#2 10.98±0.02 (stat.) ±0.30 (sys.)
94±6.0 (stat.) +43, -28 (sys.)
226.2(4- + 3-)
#3 19.30±0.03 (stat.) ±0.30 (sys.)
59±6.7 (stat.) +55, -18(sys.)
287.5(4+ + 5+)
Red : calculation with SLAGreen : calculation with KMAID
Result
(78)
(122)
(77)APFB2011 in Korea (T.Gogami) 110
28Si(e,e’K+)28Al
• First sd-shell hypernuclear spectroscopy by (e,e’K+)• Three major peaks ; #1:[(d5/2)-1
p,(s1/2)], #2:[(d5/2)-1
p,(p3/2,p1/2)] #3:[(d5/2)-1
p,(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+)7He
#1
Observation of 7He w/ good statistics
Fitting Result (40)APFB2011 in Korea (T.Gogami) 112
-B= -5.36 w/o CSB -5.16 w/ CSB
CSB effect by cluster modelFour-body cluster model
E.Hiyama et al.PRC80,054321(2009)
NN
Phenomenological potential
APFB2011 in Korea (T.Gogami) 113
7Li(e,e’K+)7He
J -B [MeV]
Cross section [nb/sr]
SLA KMAID
1/2+ -5.36 13.2 9.7
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.)
Result
#1
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.)
Red : calculation with SLAGreen : calculation with KMAID
(40)
APFB2011 in Korea (T.Gogami) 114
7Li(e,e’K+)7He
• 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 # of peak
[counts]# of BG(3s)
[counts]S/N Sys. Err.
(Contami. -%)Sys. Err.
(Loss +%)7He:#1 120 230 0.52 30 30
12B:#1 630 561 1.12 5 30
12B:#2 695 706 0.98 20 30
28Al:#1 145 360 0.40 40 30
28Al:#2 240 516 0.47 40 30
28Al:#3 77 545 0.14 90 30
APFB2011 in Korea (T.Gogami) 116
APFB2011 in Korea (T.Gogami) 117