Reconstruction, January 20, 2008

Hi guys,

I'm sorry for taking so long to get back to this. What you have sketched out looks like a great start. I think what would be really useful is to take these analyses all the way through to amplitude analysis.

You may want to take a look at section 5.5 of GlueX-doc 989. This is some documentation on physics analysis simulations with the calorimeter that Mihajlo and I worked on. As I wrote in this document I think there are two key issues:

- validating that the detector performs sufficiently well to separate exclusive final states (signal) from other photoproduction background - validating that the acceptance of the detector is sufficient to do meaningful amplitude analysis

If you could demonstrate that both of these are true for a few reactions of interest such as 1 and 2 then that would be absolutely fantastic. This is what Mihajlo and I set out to do for the calorimetry review, but probably only marginally pulled off the first part using the full calorimetry reconstruction and never really quite made it to the second part.

I think the first step for an effort like this is to really focus on the reconstructing a couple of these exclusive decay chains. How well can separate some channel like eta pi or b1 pi from background? What is the efficiency? To do a decent job at evaluating potential backgrounds I think we're going to need a mountain of PYTHIA background events. We had a lot for these studies, but as you can see in the note, the statistical fluctuations in the background (e.g. Fig 5.19) are really large. We can discuss strategies for doing this efficiently.

Of course we are happy to help support this however we can with ideas, software, etc. If you'd like, perhaps we can setup a regular teleconference. (We've finally got modern teleconferencing capability now.) That might help keep the information pipeline between Regina and Indiana flowing (so you're not waiting a week for me to respond to an email message!)

Cheers,

Matt