E Analysis Update for the (e, e’K + ) spectroscopy exp. done in 2005 Yuncheng Han (Hampton University) for HKS-HES Collaboration Jan. 13, Hall C User Meeting

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 CH 2 data w/ new optics Summary

Overview of the E Experiment Setups

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!!!!

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

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

Focal Plane Data W/ Initial Optics - X vs Y w/ svx

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

Design: 780A, 1.546T Exp: A, 8.5% up, Excitation curve  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 ENGE Splitter

Designed Splitter Magnetic Field

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

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

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

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

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

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

Summary  E analysis update status was reported: Λ 12 B confirmed Hall A published data w/ better resolution Λ 7 He was observed with enough statistics 1 st time, paper was drafted Λ 28 Al was the 1 st medium-heavy hyper nuclear spectrum with s-, p-, d- shell states indentified individually  Analysis procedure of E 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

Emax Y X Dipole Magnetic Field Emin Y X Dipole Magnetic Field EmaxEmin X Y Q1 Magnetic Field EmaxEmin X Y Q2 Magnetic Field EmaxEmin

Sieve Slit using in E01-011