Radphi Video Conference 4/01/03

April 1, 2003
University of Connecticut
Storrs, CT

Present: R. Jones, M. Kornicer, D. Steiner, D. Armstrong, S. Teige, D. Krop, D. Sober, E. Smith

• Theresa Conway thconway@indiana.edu - make sure she is on the Radphi mailing list.
• Dan has remade the H00 self check plot and will post it. He has also generated 100,000 (reconstructed) more high-mass events for 2&pi0;° sample and will post new PWA results. He has come up with a method to search for ambiguous solutions and he is writing a new code o implement the solution. He has a short note describing his method and will send around a link before next call.

• He has finished the BSD and CPV timing offsets. He will send me his fit results. We will post the histograms in a big hbook file on our Uconn web site.
• Next, he wants to redo his existing analysis with the new timing calibration to see what hes changed.

• link at http://zeus.phys.uconn.edu/~kornicer/radphi/LGDresolution/#q4.
• He showed the benchmark samples. The Ncpv<2 cut did not seem to affect the π° distribution much, except to reduce the overall magnitude by ˜ 30%. His η->2γ sample showed a cleaner signal over background when a cluster separation cut of 20-55 cm was made, in addition to the regular cuts previously discussed. The suggestion is to keep the Ncpv<2 because we are not hunting for statistics in these channels.
• In the 3γ sample there is a strong π° and a small η signal - must be from broken 2γ events. Reject of single-block cluster did not have much of an effect. The &pi0; peak is effectively removed by cluster cleanup rejection. Dan steiner will check the 3γ mass distribution with cluster-reclaim and see if he still has a strong π° signal. The sample under study is 8560 run. After he requires a &pi0; a more clean ω peak shows up, with maybe 1:3 signal over background. Dave Armstrong recalls that a cluster energy threshold of 500 MeV/c² was useful to improve the signal/noise. Dan Steiner used 4.8$#60;Etot<6.2 GeV and made a clean ω. He also used LGD cluster_cleanup.
• He showed 3π° mass spectrum and had a clean η signal.

• Existing parametrization based on fits to hadronic spectra when applied to radiative processes do not describe Kloe spectra. She can fit it but it requires some changes to their best-choice couplings.