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Overview
BGV Callibration Using Gradphi Monte Carlo PWA Formalism for Spin 1 Beam Moments of the Angular Distribution Future Prospects
Goals of Analysis Radphi Has Largest Sample of
Photoproduced 00 in the World Large Sample Allows For Quality
Measurement of f0(980) Phase Shift
BGV Calibration Overview Calibrating BGV To Use As Veto
Only 2 Kinds of Calibration
Timing w/ Respect to Tagger BSD Overlay of Recoil Proton
Timing Requires New Map Entries BSD Overlay is Simple Clock
Function
BGV Timing Calibration Timing Distributions (TDC-Tagger)
Fit to Gaussians and Means Extracted
Means Used to Create New Map Entries for Upstream and Downstream TDC
Corrected Distributions Show a Range of 15-20 ns Around 0
BGV Time Difference
•With Offsets Applied
•For Upstream Channel 4 in Run 7948
• 15-20 ns Timing Window
Gradphi Monte Carlo Studies Had 111,823 Events in Data Want to Have 10xData in Accepted
MC Generated 4 Events Flat in Mass
From Threshold to 1.5 GeV w/ =6.4 Simulated All Data Cuts (except BGV) 97.2 M Events Generated 1.13 M Events Accepted
Monte Carlo Acceptance
1.5 M Events Generated
GEO Trigger (pre-processing) Not Used in Big MC Run
Greatest Loss Through Strict Photon Energy Cut (>5 GeV)
Hypothesis Sorting Only Fails 6%
Acceptance w/o GEO was 1.16%
Invariant Mass
Uncorrected Mass Distribution Acceptance Corrected Distribution
97.2 M Generated MC Events
PWA Formalism In Case of Spinless Beam (e.g.
,K) m=0,1 in PWA Baryon Helicity Can Impart At Most
m=1 to Meson Resonance In Photoproduction m=2 Can
Contribute New Convention For Wave
Amplitudes Needed
Reflectivity Basis
Basis For the Amplitudes That Has the Following Properties:
2 eigenvalues for operator: =+1,-1 D functions real for =-1, imaginary
for =+1 Eigenvalue coincides with naturality
of exchanged particle in p Xp
PWA Conventions
Amplitude in Reflectivity Basis Can Be Written
U()=Vl mAl m()
Convention w/ m=2 included:[l]0=(-)Vl 0 [l]1-=(-)Vl 1 [l]2-=(-)Vl 2
[l]1+=(+)Vl 1 [l]2+=(+)Vl 2
V=production amp., A=decay amp., =reflectivity