Radphi Video Conference 3/11/03

March 11, 2003
University of Connecticut
Storrs, CT

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

• link at anthrax.physics.indiana.edu/~teige/nim.html
• Scott is going to release draft 1.0 by Monday Mar 17 and will send around a note requesting comments. He will post an editorial deadline like 10 days for changes from readers. Changes should be referenced to a particular draft version.

• MK is doing a systematic comparison of the shower shape in real data and Monte Carlo http://zeus.phys.uconn.edu/~kornicer/radphi/psfp/#q7.
• He decided to compare shapes systematically based on polynomial moments. This comparison showed some difference, particularly in the kurtosis (4-th moment) along the transverse axis of the shower (φ direction as opposed to r). He decided to study the Cerenkov efficiency vs shower particle track angle to see if the model is accurate. He found a strong dependency of efficiency on shower track angle and so he switched on detailed Cerenkov tracking to get as accurate a simulation as possible. Right now he has tried different wrapping schemes and finds that the major differences are in the shower statistics (i.e. energy resolution) rather than shower shape.
• To get a better handle on shower energy resolution in real data, we are putting together a selection of π° and η, ω events from which energy resolution in the actual detector can be deduced. From this, he will tune the Monte Carlo model by varying the efficiency until it mimics the real data as well as possible. After that, a new non-linearity correction will be created based upon the Monte Carlo shower response.

• The link is http://www.physics.wm.edu/~steiner/radphi/pass_zero.htm
• He has completed pass0 on BGV, is working on CPV and BSD. He will check in the cluster reclamation code to CVS and circulate message when he has done so.

• The link is http://dustbunny.physics.indiana.edu/~dkrop/2pi/0127
• At this web site his most recent PWA results on π°π° are shown. He shows two consistency checks: comparison of total acceptance-corrected yield from fit with the H00 moment. Some questions were raised regarding the degree of agreement seen and expected. Dan will replot this figure on a log scale to facilitate comparison. The other check was a sum rule on the normalized moments. This was working.
• He then compared the S-wave yield from PWA in the case with and without boot-strapping. Boot-strapping is the practice of using the solution from one mass point as the starting value in the fit of an adjacent bin. It tends to keep ambiguities in the solutions from jumping between choices across a small kinematic interval. Over longer intervals, the chance of a jump is bigger. To understand this Dan is studying a general scheme for chosing between ambiguous solutions. As soon as this is done he will provide a plot of the S-wave yield and S/D0 interference across the range of our mass acceptance.