Radphi Analysis at I.U. Dan Krop 9/06/02

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  0  0 in the World Large Sample Allows For Quality Measurement of f 0 (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 ns Around 0

BGV Channel vs. (t tagger -t TDC ) UncorrectedCorrected Run 7948

BGV Time Difference With Offsets Applied For Upstream Channel 4 in Run 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 DistributionAcceptance Corrected Distribution 97.2 M Generated MC Events

Momentum Transfer -t 1 <.10 GeV 2.10<-t 2 <.020 GeV 2.20<-t 3 <1.50 GeV 2.40<-t 4 <1.50 GeV 2

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(  )=   V l m  A l m (  ) Convention w/ m=2 included: [ l ] 0 = (-) V l 0 [ l ] 1- = (-) V l 1 [ l ] 2- = (-) V l 2 [ l ] 1+ = (+) V l 1 [ l ] 2+ = (+) V l 2 V=production amp., A=decay amp.,  =reflectivity

Moments

Prospects and Outlook Object-Orienting and ROOT-ifying PWA Code of M. Swat (E852) Expect Completion By End of 2002 After  0  0 PWA is Completed, Can Look at  to Verify FSI Effects Seen in E852 FSI should be same as from spinless beam Exotic production should be enhanced