e01-011 analysis update for the (e, e’k + ) spectroscopy exp. done in 2005
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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 statistics
BΛ 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
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