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

Yuncheng Han (Hampton University) for HKS-HES CollaborationJan. 13, 2012 @ 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 CH2 data w/ new optics Summary

Overview of the E01-011 Experiment Setups

Previous analysis result

coincidence timeS/A 2.5s better

MM from CH2S/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 methodInitial optics Mathematical optimum including calibrationResult

1st medium-heavy ΛA spectrum w/ s-, p-, d-shell state peaks

400 keV (FWHM)470 keV (FWHM)

Consistent w/ Hall A published data and much better resolution

1st time w/ sufficient statisticsBΛ and feature confirmed by E05-115Paper drafted: n-halo state, CSB

Focal Plane X-Xp

Focal Plane X-Y

Sieve Slit

Red: Experimental Data Blue: Simulation w/ Initial Optics

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:942.5 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 magnetSymmetric of the optics disappeared

ENGE

Splitter

Designed Splitter Magnetic Field

Y_Q2 + 0.1 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 BxScale of splitter Bx is 1.06

Scale of Bx for Q1

Scale of Bx for Q2

X (cm)

X (cm)

HKS magnetic map scale for By

X (cm)

X (cm)

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 (r

ad)

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 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