HKS collaboration meeting @JLab 2008/5/16
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HKS collaboration meeting @JLab 2008/5/16 Akihiko&Yoko @ Wedding Party 2008/5/10
description
HKS collaboration meeting @JLab 2008/5/16. Akihiko&Yoko @ Wedding Party 2008/5/10. Topics. Bug in REPLAY Blind analysis by Lulin Accuracy of Binding Energy ( 7 L He) About Cross Section. Bug in REPLAY. Multiplicity problem. Run# 56089, eventID 1954 3 tracks @ JLab ENGINE - PowerPoint PPT Presentation
Transcript of HKS collaboration meeting @JLab 2008/5/16
HKS collaboration meeting @JLab2008/5/16
Akihiko&Yoko @ Wedding Party 2008/5/10
Topics
• Bug in REPLAY
• Blind analysis by Lulin
• Accuracy of Binding Energy (7He)
• About Cross Section
Bug in REPLAY
Multiplicity problemRun# 56089, eventID 1954
3 tracks @ JLab ENGINE2 tracks @ Tohoku ENGINE
Ntuples are inconsistent parameter files and source codes should be checked
Bug in analyzer• Cut condition for ENGE momentum
(depends on “default” matrix)
• Different “default” matrix between USA and Japan
• Bug depends on multiplicity of ENGE
Event#1
Event#2
Event#3 (out of acceptance)
Event#4
…
Accept
Reject
Old ntuple vs. New ntuple
+12.1%+14.7%+17.5%+16.6%
•Fixed bug and re-analyze
Old RAP(12Jan08) vs. New RAP(04Apr08)
Target Old RAP
[events]
New RAP
[events]
Improve
CH2 25800 26530 +2.8 %
12C 159484 167387 +5.0 %
28Si 118755 125766 +5.9 %
7Li 64866 69123 +6.6 %
Number of events ….Coin ntuple Multiplicity (ENGE)RAP Coincidence between HKS and ENGE
Blind analysis by Lulin
Simulation data for blind analysis• Focal plane resolution in sigma
86 m (exf), 0.7 mrad (expfp), 210m(eyf), 2.8 mrad (eypf)110 m (hxf), 0.5 mrad (hxpfp), 110m(hyf), 0.7 mrad (hypf)
• Fixed beam energy (1853.1 MeV)• NO energy loss @ target• # of event & S/N (Updated)
moderately ( : ~2150 counts, : ~400 counts, 12B g.s. :~600 counts)
• Sieve Slit data is ready• Raster (0.25 cm × 0.25 cm) for CH2
Lulin’s blind analysis
• Tune CH2 & 12C– Add peaks of 12C one by one (maximum 6 peaks)
• Raster correction– only momentum of kaon
• Weight in the final step of tuning– 1.0(), 1.0(), 5.0 (B.E.=11.43), 0.0(B.E.=13.63),
6.0(B.E.=16.70), 3.0(B.E.=20.35), 4.5(B.E.=23.04), 6.0(B.E.=23.70)
Detailed will be shown in Lulin’s talk
* In the following pictures …… GOD : answer of simulation Lulin-tune : result from Lulin’s tuning
Lulin-tune CH2(tuned event)
Top : GOD. Bottom Lulin-tuneRED : coin. , BLACK : B.G.
Top : GOD, Bottom : Lulin-tunefor All event
Lulin-tune CH2(NOT tuned background event)
TOP : Lulin MM vs. GOD MMBOTTOM : wide region
TOP : GOD MMBOTTOM : LulinMM
Each component (xpt,ypt,dp)Lulin vs. GOD
expt eypt
edp
hxpthypt
hdp
offset due to different central momentum
Lulin-tune C12(tuned event)
Top : GOD. Bottom Lulin-tuneRED : coin. , BLACK : B.G.
Top : GOD, Bottom : Lulin-tunefor All event
Oka-tune C12(NOT tuned background event)
RED : coin. , BLACK : B.G.
Binding energy & YieldLulin analysis GOD
Binding energy
[MeV]
Yield
[counts]
Contamination
[%]
Binding energy
[MeV]
Yield
[counts]
S/N
11.43 (g.s.) ~491 4.4 11.37 (g.s.) 600 1.45
13.63 ~54 N/A N/A N/A N/A
16.70 ~191 83.6 16.31 30 0.09
20.35 ~142 42.4 20.31 100 0.27
23.70 & 23.04 ~407 1.5 23.37 550 1.28
How to estimate contamination
• Fit each peak by gaussian + offset• Fitted counts :
Integration of gaussian• Real counts :
# of real events in the peak(3)
(simulation data can be identified)• Contamination [%] =
((Fitted counts) – (Real counts)) / (Fitted counts) ×100
Contamination vs S/N ratio
Step by step missing mass
• Step 1Initial matrix ( *.1110 )
• Step 2After involving and (*.02121)
• Step 3After involving B.E.=11.43, 23.04, 23.70 (*.03307)
• Step4After involving B.E.=20.35 (*.03308)
• Step5After involving B.E.=16.70 (*.04022)
Missing mass of step1(Initial)
Top : CH2 for All eventBottom : Coin.(RED), B.G.(BLACK)
Top : C12 for All eventBottom : Coin.(RED), B.G.(BLACK)
Missing mass of step2(tune ,)
Top : CH2 for All eventBottom : Coin.(RED), B.G.(BLACK)
Top : C12 for All eventBottom : Coin.(RED), B.G.(BLACK)
Missing mass of step3(tune ,,2 major peaks)
Top : CH2 for All eventBottom : Coin.(RED), B.G.(BLACK)
Top : C12 for All eventBottom : Coin.(RED), B.G.(BLACK)
Missing mass of step4(tune ,,2 major peaks,
core#1)
Top : CH2 for All eventBottom : Coin.(RED), B.G.(BLACK)
Top : C12 for All eventBottom : Coin.(RED), B.G.(BLACK)
Missing mass of step5(tune ,,2 major peaks,
core#1,core#2)
Top : CH2 for All eventBottom : Coin.(RED), B.G.(BLACK)
Top : C12 for All eventBottom : Coin.(RED), B.G.(BLACK)
Summary• The trend is the same as Okayasu’s result• The linearity between reference masses ( and
) seems OK but the outside is deformed• Background contamination in 12C peaks
(Especially C.E. peaks) • The background events which were not used for
tuning do not make peak• Accuracy of binding energy :
< 0.1MeV for S/N > 1.3
~0.4 MeV for S/N < 0.4
Comments on 7He
Okayasu Spectrum
Lulin Spectrum
Lulin Mass : 6716.71 MeV/c2
(atomic masses are used)
Lulin Binging energy : -5.53 MeV/c2
Okayasu Mass : 6716.15 MeV/c2
(nuclear masses are used)
Okayasu Binging energy : -5.07 MeV/c2
Lulin 6He +2e-+ : 6722.2413 MeV/c2
6He + : 6721.20 MeV/c2
= 0.46 MeV
+ n + n +
Accuracy of Binding Energy
7Li target (A = 7) E. HiyamaPrivate Comm.
7Li(e,e’K+)
-5.40 (EXP)
-3.79 (EXP)
Possible Charge Sym. Breaking?
-6.06 +-0.2+-0.1 (Okayasu)
-6.52 (Lulin)
Summary (Accuracy of Mass Scale)
460 keV/c ambiguity/inconsistency is too large todiscuss CSB of 7
He.
Missing mass formula should be double-checked. Nuclear masses should be used.
Non-linearity check for extrapolation of mass scale
Cross section
Replay’s bug affects the result.12
B …. REPLAY loss 5%
Okayasu
57
87
Okayasu vs Lulin 12B
N(gs) ~ 250N(p) ~ 380
N(gs) ~ 670N(p) ~ 970
X 2.7X 1.7
57
87
154
235
Some of efficiencies should be different.
S/N ~ 0.65 S/N ~ 1.1
X 2.7 X 1.7
97
148
Okayasu vs Lulin 7He
N(gs) ~ 94
S/N ~ 1.67
N(gs) ~ 112
S/N ~ 1.75
12.8
X 1.2X 1.05
15.3
X 1.2 X 1.05
13.4
Summary
Inconsistency exists between Okayasu and Lulin 12
B cross-sections.
For 7He, cross-sections seem consistent
between O, L and theories.
Number of events in 12B spectra should be re-checked.
