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Λ hypernuclear spectroscopy at Jefferson Lab

Λ hypernuclear spectroscopy at Jefferson Lab. The 3 rd Korea-Japan on Nuclear and Hadron Physics at J-PARC, a t Inha University in Korea 2014/3/20 – 2014/3/21 Graduate school of Science, Tohoku Univ. Toshiyuki Gogami. Contents. Introduction ( e,e’K + ) reaction experiment

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Λ hypernuclear spectroscopy at Jefferson Lab

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  1. Λ hypernuclearspectroscopy at Jefferson Lab The 3rd Korea-Japan on Nuclear and Hadron Physics at J-PARC, at Inha University in Korea 2014/3/20 – 2014/3/21 Graduate school of Science, Tohoku Univ. Toshiyuki Gogami

  2. Contents • Introduction • (e,e’K+) reaction experiment • JLab E05-115 • Analysis • Energy scale calibration • Binding energy systematic error estimation • Results • 12C(e,e’K+)12ΛB • 7Li(e,e’K+)7ΛHe

  3. Contents • Introduction • (e,e’K+) reaction experiment • JLab E05-115 • Analysis • Energy scale calibration • Binding energy systematic error estimation • Results • 12C(e,e’K+)12ΛB • 7Li(e,e’K+)7ΛHe

  4. Spectroscopic experiment by the (e,e’K+) reaction pe’ e + p➝ e’ + K+ + Λ e- e’-Spectrometer γ* Coincidence Missing Mass MHY High intensity (~1014 Hz) Small emittance (2μm・mrad) Small energy spread (ΔE/E < 10-4) 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 sub-MeV • p  Λ

  5. Spectroscopic experiment by the (e,e’K+) reaction pe’ e + p➝ e’ + K+ + Λ e- e’-Spectrometer γ* Coincidence Missing Mass MHY High intensity (~1014 Hz) Small emittance (2μm・mrad) Small energy spread (ΔE/E < 10-4) p K+ Λ JLab E05-115 (2009) 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 sub-MeV • p  Λ

  6. Physics motivation for JLab E05-115 • 7ΛHe • CSB effect in ΛN interaction • Λ Glue like role • 10ΛBe • CSB effect in ΛN interaction • Λ Glue like role • Level inversion due to nuclear deformation • 12ΛB • Consistency confirmation with old data • Finer structures with best resolution • 52ΛV (the first challenge for medium-heavy mass region) • Λ single particle potential

  7. Physics motivation for JLab E05-115 • 7ΛHe • CSB effect in ΛN interaction • Λ Glue like role • 10ΛBe • CSB effect in ΛN interaction • Λ Glue like role • Level inversion due to nuclear deformation • 12ΛB • Consistency confirmation with old data • Finer structures with best resolution • 52ΛV (the first challenge for medium-heavy mass region) • Λ single particle potential

  8. 7ΛHe hyprenucleus Resonant state 6He 7He Λ Bound state α α + n n Unbound Bound n n Λ CSB effect Λ

  9. CSB interaction test in A=7 iso-triplet comparison 7ΛBe Counts 7ΛLi Counts H.Tamura et al., PRL 84, 5963 (2000) α α α n p n Λ p Λ p n Λ Counts 7ΛHe BΛ[MeV]

  10. CSB interaction test in A=7 iso-triplet comparison S.N.Nakamura et al., PRL 110, 012502 (2013) + JLab E01-011 -5.68 ± 0.03 ± 0.25 α α α n p n Λ p Λ p n Λ

  11. 7ΛHe in JLab E05-115 Resonant state S.N.Nakamura et al., PRL 110, 012502 (2013) + • JLab E05-115 • Small systematic error • Observation of the excited state Bound state Unbound Bound CSB effect -BΛ(1/2+) = -5.68 ± 0.03 ± 0.25

  12. Experimental setup Pre-chicane beam line Δp/p ~ 2 × 10-4 Δp/p ~ 2 × 10-4 θe’ = 6.5 ± 5.0 [degree] θK = 5.7 ± 4.6 [degree]

  13. Experimental setup

  14. Experimental setup

  15. Contents • Introduction • (e,e’K+) reaction experiment • JLab E05-115 • Analysis • Energy scale calibration • Binding energy systematic error estimation • Results • 12C(e,e’K+)12ΛB • 7Li(e,e’K+)7ΛHe

  16. Absolute energy scale calibration with Λ andΣ0 Reference plane x, x’, y, y‘ @ RP Backward transfer matrix p, x’, y’ @ Target Target Missing mass

  17. Absolute energy scale calibration with Λ andΣ0 x, x’, y, y‘ @ RP Backward transfer matrix ITERATION Tune p, x’, y’ @ Target Missing mass

  18. Λ,Σ0 comparison Before (Δp/p ~ 10-3) 4 MeV (FWHM) 1.6 MeV (FWHM) After (Δp/p ~10-4) ~ 0.5 MeV (FWHM) for 12ΛB

  19. Λ,Σ0 comparison Before (Δp/p ~ 10-3) 4 MeV (FWHM) How good is the binding energy determined ? (Systematic error) 1.6 MeV (FWHM) After (Δp/p ~10-4) ~ 0.5 MeV (FWHM) for 12ΛB

  20. Systematic error estimation for binding energy ( TOSCA + Geant4 )

  21. Systematic error estimation for binding energy • Realistic • S/N • Yields • Energy straggling in target • Beam raster • Spectrometer acceptance • Detector resolution

  22. Systematic error estimation for binding energy Compare • Realistic • S/N • Yields • Energy straggling in target • Beam raster • Spectrometer acceptance • Detector resolution

  23. Systematic error estimation for binding energy Compare • Realistic • S/N • Yields • Energy straggling in target • Beam raster • Spectrometer acceptance • Detector resolution keV

  24. Contents • Introduction • (e,e’K+) reaction experiment • JLab E05-115 • Analysis • Energy scale calibration • Binding energy systematic error estimation • Results • 12C(e,e’K+)12ΛB • 7Li(e,e’K+)7ΛHe

  25. Definition of differential cross section Number of target nucleus Efficiencies HKS acceptance Number of virtual photon including HES acceptance

  26. 12C(e,e’K+)12ΛB spectrum Preliminary pΛ sΛ

  27. 12C(e,e’K+)12ΛB spectrum (FWHM: 0.5 MeV) Preliminary

  28. D.J.Millener, NPA691, 93 (2001) ① 12ΛC and 12ΛB comparison T.Motoba et al., PTP suppl. 185, 224 (2012) ② A.Matsumura, Doctor’s thesis (2009) ③ (FWHM: 1.4 MeV) 12ΛC 12ΛB (π+,K+) reaction H.Hotch et al., PRC64, 044302 (2001) 12ΛC (FWHM: 0.5 MeV) 12ΛB JLab E01-011 JLab E05-115 KEK E369 Calc. Calc. Preliminary ② ① ③

  29. 12ΛB comparison SΛ pΛ

  30. Results for 7Li(e,e’K+)7ΛHe Resonant state (FWHM: 1.3 MeV) , Bound state Unbound Bound Preliminary CSB effect

  31. Results of 7ΛHe S.N.Nakamura et al., PRL 110, 012502 (2013) JLab E05-115 (Preliminary) JLab E01-011 -5.68 ± 0.03 ± 0.25 α α α n p n , Λ p Λ p n Λ Preliminary

  32. Results of 7ΛHe S.N.Nakamura et al., PRL 110, 012502 (2013) , EΛ

  33. Summary • JLab E05-115 experiment (2009) • Λ, Σ0, 7ΛHe, 9ΛLi, 10ΛBe, 12ΛB and 52ΛV • 12ΛB • Best resolution • Consistent with past experiments • 7ΛHe • 1/2+ with small systematic error • 2+ (core)  3/2+,5/2+ (7ΛHe) was measured

  34. Outlook • Systematic error • Fitting to the histogram • 52ΛV

  35. Backup

  36. 12C(e,e’K+)12ΛB spectrum Count Cross section Virtual photon flux Efficiencies Acceptance

  37. Λ binding energy for 12C(e,e’K+)12ΛB (FWHM: 500 keV) Click to see previous results

  38. 12ΛB comparison SΛ pΛ

  39. 10B(e,e’K+)10ΛBe spectrum Count Cross section Virtual photon flux Efficiencies Acceptance

  40. Λ binding energy for 10B(e,e’K+)10ΛBe Old data (3 points) 8.910.60(1) 8.310.61(1) 9.300.26(2) (FWHM: 780 keV) • T.Cantiwell et al., NPA236 (1974) 445-456 • M.Juric et al., NPB52 (1973)1-30

  41. Λ binding energy for 10B(e,e’K+)10ΛBe Old data (3 points) 8.910.60(1) 8.310.61(1) 9.300.26(2) Motoba’s calc. (FWHM: 780 keV) -8.84 without CSB -8.76 with CSB Hiyama’s calc.

  42. 7Li(e,e’K+)7ΛHe spectrum Count Cross section Virtual photon flux Efficiencies Acceptance

  43. Missing mass spectra • 9Be(e,e’K+)9ΛLi • 52Cr(e,e’K+)52ΛV

  44. 9Be(e,e’K+)9ΛLi spectrum Count Cross section Virtual photon flux Efficiencies Acceptance

  45. 9Be(e,e’K+)9ΛLi spectrum

  46. 9Be(e,e’K+)9ΛLi spectrum M.Sotonaand S.Frullani, PTP supplement No.117 (1994)

  47. 9Be(e,e’K+)9ΛLi spectrum rough comparison J.J.LeRose et al., NPA804(2008)116-124 F.Cusanno et al., NPA835(2010)129-135 Hall-A Hall-A Hall-C Hall-C

  48. Missing mass spectrum of 52Cr (e,e’K+)52ΛV JLab E05-115 52Cr (e,e’K+)52ΛV sΛ(?) Accidental background

  49. Missing mass spectrum of 52Cr (e,e’K+)52ΛV JLab E05-115 52Cr (e,e’K+)52ΛV Accidental background

  50. Missing mass spectrum of 52Cr (e,e’K+)52ΛV JLab E05-115 52Cr (e,e’K+)52ΛV Accidental background

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