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HES-HKS and KaoS meeting

HES-HKS and KaoS meeting. 29Nov2013 Toshiyuki Gogami. Contents. Simulation Mass resolution Energy loss correction. Resolution. Target thickness. User name Nue Log entry time 14:26:05 on September 17, 2009 Entry number 185809 This entry is a followup to:  185803

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HES-HKS and KaoS meeting

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  1. HES-HKS and KaoS meeting 29Nov2013 Toshiyuki Gogami

  2. Contents • Simulation • Mass resolution • Energy loss correction

  3. Resolution

  4. Target thickness • User name Nue • Log entry time 14:26:05 on September 17, 2009 • Entry number 185809 • This entry is a followup to: 185803 • keyword=Target Thickness UpdatedI used a wrong weight for Chromium 52. #1 should be 67.6mg as shown inFig1 of HCLog 185803. Its thickness should be 141.1mg/cm2.------ Changeable target plate #1 ------Position 0 : Water (5mm) : 500mg/cm2Position 1 : BeO (267mg, 1.764cm2) : 151.4mg/cm2Position 2 : Chromium 52 (67.6mg, 0.479cm2 : 141.1mg/cm2) :Position 3 : Boron 10 (39.9mg, 0.69cm2 : 57.8mg/cm2)Position 4 : Boron 11 (48.3mg, 0.69cm2 : 70.0mg/cm2)Positoin 5 : Carbon nat. (158.3mg, 1.81cm2 : 87.5mg/cm2 )Position 6 : Lithium 7 (325.2mg, 0.982cm2 : ?? 331.2mg/cm2)Thickness of Lithium is 3.9mm, using density of 0.535g/cm3,it is 207mg/cm2. Weight of Li7 may be heavier than real value sinceit had been soaked in oil.----:A copy of this log entry has been emailed to: reinhold@jlab.org, nakamura@jlab.org, tangl@jlab.org, maruta@jlab.org

  5. Rough estimation of mass resolution for each target Assumptions : • ⊿pbeam/pbeam~3.0 x 10-5 , ⊿pe’,K/pe’,K~2.0 x 10-4 , ⊿θ ~ 1 mrad • Without energy struggling, mass shift and raster effects. Beam momentum Angles of kaon and scattered electron Momenta of kaon and scattered electron Unit iskeV/c2

  6. Energy losses ( 7Li target ) ΔEK ΔEe’ Thickness of 184 mg/cm2 ~300keV ~400keV SIMULATION ΔEe Comments after this work Maybe , I should have used ΔEe’~220 keV, ΔEe~220 keV and ΔEe’~260 keV. But, I just wanted to see mass shift effect very roughly this time. ~300keV

  7. Three sample points K+ Generation point • Back ΔEK=0, ΔEe’=0, ΔEe=300 keV • Center ΔEK=400/2, ΔEe’=300/2, ΔEe=300/2 keV • Front ΔEK=400, ΔEe’=300, ΔEe=0 keV e’ Back Very simple assumption Center Front e Calculate missing mass with them Next page

  8. Mass shift Substitute, E = E – ΔE ( p = p – Δp) • Back edge ΔEK=0, ΔEe’=0, ΔEe=300 keV • Center ΔEK=400/2, ΔEe’=300/2, ΔEe=300/2 keV • Front edge ΔEK=400, ΔEe’=300, ΔEe=0 keV CALCULATION

  9. Missing mass for each point (1) Note that resolutions are not included. (2) Please neglect their widths in this histogram, and focus on their center values CALCULATION

  10. In the full simulation SIMULATION Missing mass [MeV/c2] Target z [cm] • Mass shift • Energy loss difference for each particle, depending on z position in target • Mass resolution • Spectrometers (detector) • Multiple scattering • Energy struggling • Etc.

  11. Assumed resolutions in the simulation Beam energy spread 3.0 x 10-5 taken from Elog (SLI monitor) HES resolutions δxe’ = 97 μm δx’e’ = 0.8 mrad δye’ = 120 μm δy’e’ = 1.5 mrad HKS resolutions δxK= 100 μm δ x’K= 0.2 mrad δyK= 160 μm δ y’K= 0.3 mrad Obtained from real data analyses

  12. Expected resolution for each target Included all of these effects • Detector resolution • Multiple scattering • Energy struggling • Realistic acceptance • Raster (7Li, CH2) • Mass shift !!! • Etc.

  13. Energy loss correction

  14. Energy loss correction K+ e’ 12C e

  15. After energy loss correction Fitted by a single Gaussian function with its range of 0 +- 400 keV 12ΛB 10ΛBe Mean: 112 keV Fitting mean: -33 +- 5 keV Mean: 118 keV Fitting mean: -5 +- 4 keV

  16. Summary • Estimated mass resolutions • Energy loss correction works

  17. Core-2-Core • In Czech Republic • Elementary cross section • 12ΛB cross section for all runs. • 7ΛHe excitation energy • ( Blind analysis )

  18. Backup

  19. Rough estimation of mass resolution for each target Assumptions : • ⊿pbeam/pbeam~1.0 x 10-4 , ⊿pe’,K/pe’,K~2.0 x 10-4 , ⊿θ ~ 3 mrad • Without energy strugglingand raster effects. Beam momentum Angles of kaon and scattered electron Momenta of kaon and scattered electron Unit iskeV/c2

  20. Rough estimation of mass resolution for each target Beam momentum Angles of kaon and scattered electron Momenta of kaon and scattered electron

  21. Lambda

  22. 12ΛB

  23. Energy losses ( CH2 target ) ΔEK ΔEe’ Λ 700 keV 900 keV ΔEe 700 keV

  24. Energy losses ( 7Li target ) ΔEK ΔEe’ ~300keV ~400keV ΔEe ~300keV

  25. Energy losses ( 10 B target ) ΔEK ΔEe’ 60keV 80 keV ΔEe 60 keV

  26. Energy losses ( 12C target ) ΔEK ΔEe’ 150keV 180keV ΔEe 130keV

  27. Energy losses ( 52Cr target ) ΔEK ΔEe’ 150keV 180keV ΔEe 150keV

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