The Carnegie Mellon Partial Wave Analysis Project
Status Report on July 5, 2000

This is a follow-up on the June 30 report where we were seeing some problems in comparing weights. We have traced this down to a bug on our end where we accidently polarized part of the data. After fixing this problem, we now can compare the weight from Adam's code with that from pwa2000 for unpolarized data. The ratio of the two is shown below. This is exactly what we expect this to look like. We know that there are differences in the two weights at the level of the Breit-Wigners for both the a₂ and the . Adam is using a non-relativistic form, while pwa-2000 uses a relativistic form. Other subtle differences also exis, but these should not affect the fiting.

We have also normalized the two weights, and plotted one against the other. For Adam's code, the normalization factor is 1/90,700,000, while for pwa200 it is 1/500. In order to allow one to easily see the higher weight region, we have plotted on a logarithmic z-scale. Finally, a comment on notation that we use. When looking at polarization, we have been consistently polarizing alon the y-axis in the lab fram. We define as the angle between the polarization vector and the normal to the production plane in the GJ system. In fact, we are a bit sloppy, and define this as the angle between the y-axis and the normal to the production plane. So even though we set the polarization to zero, we can consistently define . However, as all functions of are multiplied by the polarization, the dependence on vanishes for an unpolarized beam.