Radphi Video Conference 4/29/03

April 29, 2003
University of Connecticut
Storrs, CT

Meeting Agenda:

1. Understanding differences in mass spectra - W&M
2. Strange bump seen in 2gamma mass specttra - UConn
3. Shower energy resolution in LGD - UConn
4. Progress on BGV reconstruction - Indiana
5. Progress on pwa - Indiana
6. Next steps to NIM paper - Indiana

• http://www.physics.wm.edu/~steiner/radphi/reclaim.htm"
• http://zeus.phys.uconn.edu/~kornicer/radphi/LGDresolution"
• http://zeus.phys.uconn.edu/radphi/call-notes"

Present: R. Jones, M. Kornicer, D. Steiner, D. Armstrong, D. Krop, Theresa Conway , E. Smith

• did work with Mihajlo to resolve differences between their Nγ mass spectra. The difference had to do with hidden cuts in the analysis:
  • dead_block suppression
  • single-block cluster suppression
  • minimum cluster energy cut
• Dan will look at a best choice for minimum cluster energy cut and make a recommendation for next conference call.

• link at zeus.phys.uconn.edu/~kornicer/radphi/LGDresolution/res_2g/ .
• Strange bump seen at low mass in m(2γ) spectra: He analyzed some old ρ->π+π- for 2γ reconstruction and found the same peak at low mass.
• He showed a plot with results for single cluster energy resolution for η and π°. The π° resolution is significantly worse then the η. Elton suggested that this might arise from the position uncertainty on the shower centroid, which is expected to have a larger effect on the π° than on the η. This should be possible to check in the Monte Carlo. The fit shown by Mihajlo for the η gives resolution σ(E)/E = 2% + 11%/sqrt(E). This is worse than most people have claimed for lead glass. Elton suggested that some word of explanation be given in the paper for why this detector shows degraded resolution. Richard asked Scot (through D. Krop) to show a similar figure for σ(E)/E obtained with the E852 data, which may differ from the test beam results (LINK).

• He is still working on the ambiguity finder. So far progress has been limited on denumerating all of the ambiguities in γp -> pπ°π°. R. Jones has ideas he will discuss with Dan before the next conference call.

• Theres has put together a nice summary presentation in Power Point on this project at http://k9.physics.indiana.edu/tof/thconway/bgv/index.shtml