1 / 33

JLab における 中重 ラムダハイパー核分光研究

JLab における 中重 ラムダハイパー核分光研究. 東北大学理学研究科 後神　利志. Contents. Introduction Experimental setup Analyses Missing mass Summary. Contents. Introduction Experimental setup Analyses Missing mass Summary. ( e,e’K + ) reaction. e. e. u. u. γ *. K +. –. u. s. p. d. s. u. Λ. d.

kaori
Download Presentation

JLab における 中重 ラムダハイパー核分光研究

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. JLab における中重ラムダハイパー核分光研究 東北大学理学研究科 後神　利志

  2. Contents • Introduction • Experimental setup • Analyses • Missing mass • Summary

  3. Contents • Introduction • Experimental setup • Analyses • Missing mass • Summary (e,e’K+) reaction e e u u γ* K+ – u s p d s u Λ d

  4. Spectroscopic experiment by the (e,e’K+) reaction pe’ e + p➝ e’ + K+ + Λ e- e’-Spectrometer γ* Coincidence Missing Mass MHY p K+ Λ n K+-Spectrometer pK+ target nucleus • ~ 1990’s • The (K-,π-) , (π+,K+) reactions • Energy resolution ~ a few MeV • n Λ • 2000~ • The (e,e’K+) reaction • Energy resolution ~0.5 MeV • p  Λ

  5. Experimental motivation • JLab E05-115 (2009, Hall-C) • Elementary processes (Λ,Σ0) • 7ΛHe[1], 9ΛLi, 10ΛBe • ΛN charge symmetry breaking • ΛN-ΣN coupling • 12ΛB[2][3][4] • Consistency check with the past experiments • Check analysis progress • 52ΛV • Single particle energy • For measurements with heavier targets [1]S.N.Nakamura et al., PRL 110, 012502 (2013) [2] T.Miyoshi et al., PRL 90, 232502 (2003) [3] L.Yuan, PRC 73, 044607 (2006) [4] M.Iodice, PRL 99, 052501 (2007)

  6. Contents • Introduction • Experimental setup • Analyses • Missing mass • Summary HES

  7. Experimental setup 10 msr 10 msr

  8. Contents • Introduction • Experimental setup • Analyses • Missing mass • Summary

  9. Analysis

  10. Analysis x, x’, y, y’ x, x’, y, y’ @ Reference plane @ Reference plane p, x’, y’ p, x’, y’ @ Target Missing Mass

  11. Energy scale calibration x, x’, y, y’ @ RP Polyethylene target (0.45 g/cm2) e, K+ Inverse transfer matrix FWHM ~ 1.8 MeV p, x’, y’@ Target

  12. Background events in the HKS REAL DATA SIMULATION 9Be , 38.4 [μA] • 52Cr target • Luminosity ( 1/10 ) • Worse S/N • Tracking is not easy KDC1 x [cm] KDC2 y [cm] KDC1 e+ KDC2 z [cm]

  13. Tracking efficiency and residual σ ~ 160 μm σ ~ 350 μm Plane efficiency Tracking residual

  14. Contents • Introduction • Experimental setup • Analyses • Missing mass • Summary

  15. 10ΛBe, 12ΛB histograms 10B(e,e’K+)10ΛBe 12C(e,e’K+)12ΛB NsΛ~190 FWHM~0.9 MeV FWHM~0.9 MeV sΛ sΛ pΛ Preliminary Preliminary Quasi-free Λ Quasi-free Λ Accidental Background Accidental Background NsΛ~530

  16. 52Cr(e,e’K+)52ΛV Preliminary Quasi-free Λ Accidental Background Nbind~870

  17. Summary and outlook • JLab E05-115 (2009) • Λ, Σ0, 7ΛHe, 9ΛLi, 10ΛBe, 12ΛB, 52ΛV • Analyses are in progress • Matrix tuning • Blind analysis • Efficiencies

  18. E05-115 collaboraton

  19. Backup

  20. Hit wire selection REAL DATA CH2 Target CUT CUT 52Cr Target REAL DATA Black : hit wires Blue : selected wires Red : track • Compared to the conventional code • Number of K++130% • Analysis time – 30%

  21. 軽い核のミッシングマス 数、分解能 JLab E05-115, Carbon (112mg/cm2) 10LBe

  22. Energy scale calibration conversion Angle, position @ FP Angle, momentum @ Target Mx – MΛ < 100 keV/c2 e, K+ 6th order transfer matrix

  23. トラッキング困難 CH2 Target H2O Target REAL DATA REAL DATA Black : hit wires Blue : selected wires Red : track

  24. 52LV

  25. Singles rate summary HKS Up to ~30 [MHz] HKS trigger ~ 10[kHz] HES Up to ~15 [MHz] COIN 2.0 [kHz] HES trigger ~ a few[MHz] HKS-HES Collaboration Meeting, T.Gogami

  26. B.G. mix rate (real data) b a B.G mix rate = HKS-HES Collaboration Meeting, T.Gogami * hks ntulpe

  27. e+ simulation • To see • Number of event • Angle & momentum of e+ generated in target SIMULATION HKS-HES Collaboration Meeting, T.Gogami

  28. Spectroscopic experiment by the (e,e’K+) reaction pe’ e + p➝ e’ + K+ + Λ Feynman diagram e- e’-Spectrometer e e u u γ* K+ – γ* u s Coincidence p Missing Mass HHY d s p K+ u Λ Λ d n K+-Spectrometer pK+ target nucleus • ~ 1990’s • The (K-,π-) , (π+,K+) reactions • Energy resolution ~ a few MeV • n Λ • 2000~ • The (e,e’K+) reaction • Energy resolution ~0.5 MeV • p  Λ JPS meeting in Kyoto , Toshi Gogami

  29. Background events in the HKS REAL DATA SIMULATION 9Be , 38.4 [μA] KDC1 x [cm] • 52Cr target • Luminosity ( 1/10 ) • Worse S/N • Tracking is not easy KDC2 y [cm] KDC1 e+ KDC2 z [cm] ~2.24 ~4.94

  30. 10ΛBe, 12ΛB histograms 10B(e,e’K+)10ΛBe 12C(e,e’K+)12ΛB NsΛ~190 FWHM~0.9 MeV FWHM~0.9 MeV sΛ sΛ pΛ Preliminary Preliminary Quasi-free Λ Quasi-free Λ Accidental Background Accidental Background NsΛ~530

  31. Experimental motivation • JLab E05-115 (2009, Hall-C) • Elementary processes (Λ,Σ0) • 7ΛHe[1], 9ΛLi, 10ΛBe • ΛN charge symmetry breaking • ΛN-ΣN coupling • 12ΛB • Consistency check with the past experiments • Check analysis progress • 52ΛV • Single particle energy (systematic なstudy) • ls splitting, core-configuration mixing • 将来重く行くため避けられない道 [1]S.N.Nakamura et al., PRL 110, 012502 (2013)

  32. Detectors & Trigger HKS K+ p, π+ HES e- TOF walls (Plastic scintillators) HES trigger (TOF1x2) ~2000 kHz HKS trigger (TOF1x2x3) x Chrenkov ~10 kHz • Cherenkov detectors • Aerogel (n=1.05) • Water (n=1.33) Coincidence trigger HES x HKS < 2 kHz Drift chambers Core2Core in Barcelona, Toshi Gogami

  33. 52Cr(e,e’K+)52ΛV f d p Preliminary 数 s Mixed event analysis をやる

More Related