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HKS collaboration meeting @JLab 2008/5/16

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

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HKS collaboration meeting @JLab 2008/5/16

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  1. HKS collaboration meeting @JLab2008/5/16 Akihiko&Yoko @ Wedding Party 2008/5/10

  2. Topics • Bug in REPLAY • Blind analysis by Lulin • Accuracy of Binding Energy (7LHe) • About Cross Section

  3. Bug in REPLAY

  4. Multiplicity problem • Run# 56089, eventID 1954 • 3 tracks @ JLab ENGINE • 2 tracks @ Tohoku ENGINE • Ntuples are inconsistent  parameter files and source codes should be checked

  5. 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 Accept Event#3 (out of acceptance) Event#4 Reject …

  6. Old ntuple vs. New ntuple • Fixed bug and re-analyze +12.1% +14.7% +17.5% +16.6%

  7. Old RAP(12Jan08) vs. New RAP(04Apr08) • Number of events …. • Coin ntuple  Multiplicity (ENGE) • RAP  Coincidence between HKS and ENGE

  8. Blind analysis by Lulin

  9. Simulation data for blind analysis • Focal plane resolution in sigma 86 mm (exf), 0.7 mrad (expfp), 210mm(eyf), 2.8 mrad (eypf) 110 mm (hxf), 0.5 mrad (hxpfp), 110mm(hyf), 0.7 mrad (hypf) • Fixed beam energy (1853.1 MeV) • NO energy loss @ target • # of event & S/N (Updated) • moderately (L : ~2150 counts, S : ~400 counts, 12LB g.s. :~600 counts) • Sieve Slit data is ready • Raster (0.25 cm × 0.25 cm) for CH2

  10. 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(L), 1.0(S), 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

  11. Lulin-tune CH2(tuned event) Top : GOD, Bottom : Lulin-tune for All event Top : GOD. Bottom Lulin-tune RED : coin. , BLACK : B.G.

  12. Lulin-tune CH2(NOT tuned background event) TOP : GOD MM BOTTOM : LulinMM TOP : Lulin MM vs. GOD MM BOTTOM : wide region

  13. Each component (xpt,ypt,dp)Lulin vs. GOD hxpt expt eypt hypt edp hdp offset due to different central momentum

  14. Lulin-tune C12(tuned event) Top : GOD, Bottom : Lulin-tune for All event Top : GOD. Bottom Lulin-tune RED : coin. , BLACK : B.G.

  15. Oka-tune C12(NOT tuned background event) RED : coin. , BLACK : B.G.

  16. Binding energy & Yield

  17. How to estimate contamination • Fit each peak by gaussian + offset • Fitted counts : Integration of gaussian • Real counts : # of real events in the peak(3s) (simulation data can be identified) • Contamination [%] = ((Fitted counts) – (Real counts)) / (Fitted counts)×100

  18. Contamination vs S/N ratio

  19. Step by step missing mass • Step 1 Initial matrix ( *.1110 ) • Step 2 After involving L and S (*.02121) • Step 3 After involving B.E.=11.43, 23.04, 23.70 (*.03307) • Step4 After involving B.E.=20.35 (*.03308) • Step5 After involving B.E.=16.70 (*.04022)

  20. Missing mass of step1(Initial) Top : CH2 for All event Bottom : Coin.(RED), B.G.(BLACK) Top : C12 for All event Bottom : Coin.(RED), B.G.(BLACK)

  21. Missing mass of step2(tune L,S) Top : CH2 for All event Bottom : Coin.(RED), B.G.(BLACK) Top : C12 for All event Bottom : Coin.(RED), B.G.(BLACK)

  22. Missing mass of step3(tune L,S,2 major peaks) Top : CH2 for All event Bottom : Coin.(RED), B.G.(BLACK) Top : C12 for All event Bottom : Coin.(RED), B.G.(BLACK)

  23. Missing mass of step4(tune L,S,2 major peaks, core#1) Top : CH2 for All event Bottom : Coin.(RED), B.G.(BLACK) Top : C12 for All event Bottom : Coin.(RED), B.G.(BLACK)

  24. Missing mass of step5(tune L,S,2 major peaks, core#1,core#2) Top : CH2 for All event Bottom : Coin.(RED), B.G.(BLACK) Top : C12 for All event Bottom : Coin.(RED), B.G.(BLACK)

  25. Summary • The trend is the same as Okayasu’s result • The linearity between reference masses (L and S) 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

  26. Accuracy of Binding Energy Comments on 7LHe Lulin Spectrum Lulin Mass : 6716.71 MeV/c2 (atomic masses are used) Lulin Binging energy : -5.53 MeV/c2 Lulin 6He +2e-+ L : 6722.2413 MeV/c2 Okayasu Spectrum Okayasu Mass : 6716.15 MeV/c2 (nuclear masses are used) Okayasu Binging energy : -5.07 MeV/c2 6He + L : 6721.20 MeV/c2 D = 0.46 MeV a + n + n + L =6722.19

  27. 7Li target (A = 7) E. Hiyama Private Comm. -3.79 (EXP) Possible Charge Sym. Breaking? -5.40 (EXP) -6.06 +-0.2+-0.1 (Okayasu) -6.52 (Lulin) 7Li(e,e’K+)

  28. Summary (Accuracy of Mass Scale) 460 keV/c2 ambiguity/inconsistency is too large to discuss CSB of 7LHe. Missing mass formula should be double-checked. Nuclear masses should be used. Non-linearity check for extrapolation of mass scale S L

  29. Cross section Okayasu Replay’s bug affects the result. 12LB …. REPLAY loss 5% 57 87

  30. Okayasu vs Lulin 12LB Some of efficiencies should be different. N(gs) ~ 250 N(p) ~ 380 X 2.7 X 1.7 N(gs) ~ 670 N(p) ~ 970 S/N ~ 0.65 S/N ~ 1.1 X 2.7 X 1.7 57 97 154 87 148 235

  31. Okayasu vs Lulin 7LHe N(gs) ~ 94 X 1.2 X 1.05 N(gs) ~ 112 S/N ~ 1.67 S/N ~ 1.75 X 1.2 X 1.05 13.4 12.8 15.3

  32. Summary Inconsistency exists between Okayasu and Lulin 12LB cross-sections. For 7LHe, cross-sections seem consistent between O, L and theories. Number of events in 12LB spectra should be re-checked.

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