1. HES-HKS analysis meeting Toshi Gogami 5Mar2014

2. Contents  Cross section & Λ binding energy 12 C(e,e’K + ) 12 Λ B 10 B(e,e’K + ) 10 Λ Be 7 Li(e,e’K + ) 7 Λ He  Missing mass spectra 9 Be(e,e’K + ) 9 Λ Li 52 Cr(e,e’K + ) 52 Λ V

3. Definition of differential cross section

4. Cut conditions

5. Efficiencies and correction factors Efficiencies DAQ Trigger Tracking K + selection AC, WC, m 2, Correction factors K + decay (momentum dependent) Solid angle (momentum dependent) K + absorption Event loss due to matrix and energy loss Small effect for hypernucelus  systematic errors Acceptance (real and simulation) Small discrepancy  systematic error

6. Systematic error for cross-section Statistical error in simulation Position accuracy of collimator (1mm) Acceptance discrepancy between sim. and real Obtained by blind analysis

7. Systematic error for binding energy Blind analysis Date: 2/25 – 3/4 Time: 92.5 hours Initial matrices: distorted by hand Momentum: Λ, Σ 0 and 12 Λ B Angle : Λ and Σ 0 (Different distortion pattern from previous study was tested) Simple report  click hereclick here

8. Systematic error for binding energy Blind analysis Date: 2/25 – 3/4 Time: 92.5 hours Initial matrices: distorted by hand Momentum: Λ, Σ 0 and 12 Λ B Angle : Λ and Σ 0 (Another distortion pattern was tested) BeforeAfter IN PROGRESS

9. 12 C(e,e’K + ) 12 Λ B spectrum Virtual photon flux Efficiencies Acceptance

10. Λ binding energy for 12 C(e,e’K + ) 12 Λ B Peak- B Λ [MeV]N[nb/sr] 1 2 3 4 5 6 (FWHM: 500 keV) Click to see previous results

11. 12 Λ B comparison Experime nt θ γK Lab [degree]-B Λ [MeV]Cross section [nb/sr]Extracted value from Motoba-san’s prediction E05-1156.8-11.38 ± 0.02 ± sys. error97.8 ± 3.6 ± 11.575 E01-0115.8-11.40 ± 0.01 ± 0.04101 ± 4.2 (+ 38 – 31)85 E89-0090-11.52 ± 0.35140 ± 17 ± 18120 Emulsion-11.37 ± 0.06N/A Experim ent θ γK Lab [degree]-B Λ [MeV]Cross section [nb/sr]Extracted value from Motoba-san’s prediction E05-1156.8-0.43 ± 0.03 ± sys. error84.1 ± 3.3 ± 9.985 E01-0115.8-0.41 ± 0.01 ± 0.1394 ± 4.0 ±3596 E89-009-0.49 ± 0.16N/A

12. 10 B(e,e’K + ) 10 Λ Be spectrum Virtual photon flux Efficiencies Acceptance

13. Λ binding energy for 10 B(e,e’K + ) 10 Λ Be Peak- B Λ [MeV]N[nb/sr] 1 2 3 4 5 6 7 8 (1)T.Cantiwell et al., NPA236 (1974) 445-456 (2)M.Juric et al., NPB52 (1973) 1-30 (FWHM: 780 keV)

14. Λ binding energy for 10 B(e,e’K + ) 10 Λ Be (FWHM: 780 keV) -8.84 without CSB -8.76 with CSB Hiyama’s calc. Motoba’s calc. Peak- B Λ [MeV]N[nb/sr] 1 2 3 4 5 6 7 8

15. 7 Li(e,e’K + ) 7 Λ He spectrum Virtual photon flux Efficiencies Acceptance

16. Λ binding energy for 7 Li(e,e’K + ) 7 Λ He Peak- B Λ [MeV]N[nb/sr] 1 2 (FWHM: 1300 keV) -5.36 without CSB -5.16 with CSB Hiyama’s calc. About target thickness  click hereclick here

17. Λ binding energy for 7 Li(e,e’K + ) 7 Λ He (FWHM: 1300 keV) -5.36 without CSB -5.16 with CSB Hiyama’s calc. Peak- B Λ [MeV]N[nb/sr] 1 2

18. Missing mass spectra  9 Be(e,e’K + ) 9 Λ Li  52 Cr(e,e’K + ) 52 Λ V

19. 9 Be(e,e’K + ) 9 Λ Li spectrum Virtual photon flux Efficiencies Acceptance

20. 9 Be(e,e’K + ) 9 Λ Li spectrum

21. M.Sotona and S.Frullani, PTP supplement No.117 (1994)

22. 9 Be(e,e’K + ) 9 Λ Li spectrum rough comparison J.J.LeRose et al., NPA804(2008)116-124 F.Cusanno et al., NPA835(2010)129-135 Hall-A Hall-C

23. Missing mass spectrum of 52 Cr (e,e’K + ) 52 Λ V Accidental background sΛ (?)sΛ (?)

24. Missing mass spectrum of 52 Cr (e,e’K + ) 52 Λ V Accidental background

25. Missing mass spectrum of 52 Cr (e,e’K + ) 52 Λ V Accidental background

26. Summary and Outlook Summary Status of spectra Outlook Blind analysis  systematic error for binding energy D’s thesis

27. END

28. Backup

29. Λ binding energy for 12 C(e,e’K + ) 12 Λ B Peak-B [MeV]Number of event Cross section [nb/sr] 1-11.40 ± 0.03657±2683 ±3 3-8.37 ± 0.10135±1117 ±1 4-5.15 ± 0.18118±1115 ±1 5-1.67 ± 0.23116±1114 ±1 2-0.38 ± 0.04631±2582 ±3 6+0.82 ± 0.09240±1531 ±2 Only statistical errors ( FWHM ~ 0.89 MeV ) PREVIOUS (1/10)

30. Λ binding energy for 12 C(e,e’K + ) 12 Λ B Peak- B Λ [MeV]N[nb/sr] 1 2 3 4 5 6 (FWHM: 500 keV) Present (2/28)

31. Gaussian fitting Gaussian fit  8020 events (/10000) ~80% counting efficiency SIMULATION (after matrix tuning) 12 C, 87.5 mg/cm 2 12 Λ B (-B Λ =-11.37 MeV) [GeV] [ Counts / 100 keV]

32. Number of events after matrix tuning SIMULATION (after matrix tuning) 12 C, 87.5 mg/cm 2 12 Λ B (-B Λ =-11.37 MeV)

33. Voigt function

34. Systematic error for cross-section

35. About Lithium target thickness ELOG  Entry: 185809 Lithium 7 (325.2mg, 0.982cm 2  331.2mg/cm 2 ) Thickness of Lithium is 3.9mm, using density of 0.535g/cm 3, it is 207mg/cm 2. A photograph before mounting  already black….. Nitride ? Lithium nitridation test will be done. Go back

36. Carbon target

37. Boron target

38. Lithium target

39. Chromium target

40. 9 Be(e,e’K + ) 9 Λ Li To be update (This is made by old matrix)

41. Differential cross section of 10 B(γ*,K + ) 10 Λ Be Peak-B [MeV]Number of event Cross section [nb/sr] 1-8.66 ± 0.08141±1211.6 ±0.9 2-7.81 ± 0.2351±74.3 ±0.7 3-6.08 ± 0.09139±1211.8 ±1.0 4-5.03 ± 0.1478±96.5 ±0.7 5-1.98 ± 0.10156±1313.0 ±0.9 6-0.11 ± 0.16123±1110.0 ±0.8 72.23 ± 0.07188±1415.9 ±1.1 811.14± 0.1394 ± 107.8 ±0.8 ( FWHM ~ 0.8 MeV ) PREVIOUS (1/10)

42. Comparison with old data MeV PREVIOUS (1/10)

43. Differential cross section of 10 B(γ*,K + ) 10 Λ Be Peak-B [MeV]Number of event Cross section [nb/sr] 1-8.66 ± 0.08141±1211.6 ±0.9 2-7.81 ± 0.2351±74.3 ±0.7 3-6.08 ± 0.09139±1211.8 ±1.0 4-5.03 ± 0.1478±96.5 ±0.7 5-1.98 ± 0.10156±1313.0 ±0.9 6-0.11 ± 0.16123±1110.0 ±0.8 72.23 ± 0.07188±1415.9 ±1.1 811.14± 0.1394 ± 107.8 ±0.8 ( FWHM ~ 0.8 MeV ) -8.84 without CSB -8.76 with CSB Hiyama’s calc. Motoba’s calc. PREVIOUS (1/10)

44. Contribution to missing mass resolution One of results of blind analyses Missing masses with initial matrices Simply calculated by quadratic sum

46. Differential cross section of 12 Λ B by Motoba-san DWIA, E γ = 1.5 GeV

47. Differential cross section predicted by Motoba-san Motoba-san’s calc. 12 Λ B g.s. (1 -, 2 - ) θ Lab γK [degree] [nb/sr]

48. Angular distribution in simulation (θ Lab γK ) SIMULATION Motoba-san’s calc. 12 Λ B g.s. (1 -, 2 - ) θ Lab γK [degree] Normalized intensity θ Lab γK [degree] [Counts]

49. Predicted cross section in our acceptance SIMULATION Mean values θ Lab γK [degree] [nb/sr] Value used for comparison !!

50. Matrix optimization with 7 Λ He Toshi Gogami 27Feb2014

51. Histogram sample

52. Results # (Number of LOOPs)1 (10)2 (10)3 (5)4 (15) Angle ( Λ : Σ 0 : 7 Λ He )1:1:1 1:1:9- Momentum(Λ : Σ 0 : 12 Λ B)---1:1:1 7 Λ He convergence toFitting meanFixed (generated point) Fixed (generated point) - Width of 7 Λ He (FWHM) [keV/c 2 ] 1060 +/- 701030 +/- 70980 +/- 601030 +/- 70 ( Matrix tuning was started with not-distorted matrices.)

53. Contribution to missing mass resolution One of results of blind analyses Missing masses with initial matrices Simply calculated by quadratic sum

54. New blind analysis results 4Mar2014 Toshi Gogami

55. Blind analysis Date: 2/25 – 3/4 Time: 92.5 hours Initial matrices: distorted by hand Momentum: Λ, Σ 0 and 12 Λ B Angle : Λ and Σ 0

56. Missing mass spectra with distorted matrices ΛΣ0Σ07 Λ He 52 Λ V 12 Λ B 10 Λ Be

57. Spectrum comparison BeforeAfter

58. Results

60. H 2 O target  16 Λ N

61. Comparison with hall A data