E01-011 Analysis Update for the (e, e’K + ) spectroscopy exp. done in 2005

1. E01-011 Analysis Updateforthe (e, e’K+) spectroscopy exp. done in 2005 Yuncheng Han (Hampton University) for HKS-HES Collaboration Jan. 13, 2012 @ Hall C User Meeting

2. Outline • Previous analysis result • Motivation of the forward optics tune • Initial optics / designed optics • Focal plane & Sieve Slit pattern w/ new optics • Missing mass spectrum of CH2 data w/ new optics • Summary

3. Overview of the E01-011 Experiment Setups

4. Previous analysis result coincidence time S/A 2.5s better MM from CH2 S/A 6s better The HKS Spectrometer and ‘tilt method’ worked greatly!!!!

5. 400 keV (FWHM) 470 keV (FWHM) Consistent w/ Hall A published data and much better resolution 1st medium-heavy ΛA spectrum w/ s-, p-, d-shell state peaks s-p shell states 1~2 MeV wider but p-d shell states ~1 MeV narrower than expected NEW PHYSICS ? 1st time w/ sufficient statistics • Review of analysis method • Initial optics • Mathematical optimum • including calibration • Result BΛ and feature confirmed by E05-115 Paper drafted: n-halo state, CSB

6. Sieve Slit • Focal Plane X-Xp Focal Plane X-Y Red: Experimental Data Blue: Simulation w/ Initial Optics

8. Focal Plane Data W/ Initial Optics -X vs Y w/ svx Red: Experimental Data Blue: Simulation w/ Initial Optics

9. Focal Plane Data W/ Initial Optics -X vs Y w/ svy Red: Experimental Data Blue: Simulation w/ Initial Optics

10. ENGE Splitter Exp: 942.5 A, 8.5% up, Design: 780A, 1.546T • Splitter magnetic field was fully saturated, • The uniform region shrank sharply, • The fringe field of splitter effected the magnetic field of Q1, Q2 and ENGE magnet • Symmetric of the optics disappeared Excitation curve

11. Designed Splitter Magnetic Field

12. Magnetic map offset • magnetic map scale for Bx Scale of splitter Bx is 1.06 Splitter: (x-8) – (x-12)/5, x<0; (x+5)+(11-X)/5, x>0 Scale of Bx for Q1 Y_Q1 X (cm) Scale of Bx for Q2 Y_Q2 + 0.1 cm X (cm)

13. HKS magnetic map scale for By Splitter Q1 X (cm) X (cm) Q2 Dipole X (cm) r(m)

14. Sieve Slit Data W/ New Optics Focal Plane X-Xp Xp (rad) X (cm) Red: Experimental Data Blue: Simulation w/ New Optics

15. Focal Plane Data W/ Initial Optics –X vs Y w/ svy Red: Experimental Data Blue: Simulation w/ New Optics

16. Focal Plane Data W/ New Optics –X vs Y w/ svx Red: Experimental Data Blue: Simulation w/ New Optics

18. Comparing MM Spectrum W/ Seva’s Analysis Λ#746 Λ#827

19. Summary • E01-011 analysis update status was reported: • Λ12B confirmed Hall A published data w/ better resolution • Λ7He was observed with enough statistics 1st time, paper was drafted • Λ28Al was the 1st medium-heavy hyper nuclear spectrum with s-, p-, d-shell states indentified individually • Analysis procedure of E01-011 was reviewed, and the mathematical optimum method is powerful • Better initial optics of HKS is obtained, and about 10% more Lambda event were obtained • The residual of HKS optics is being tune now • The optics of Enge side will be studied soon