Private:Weekly Group 4/13/2011

Igor Senderovich 11:52, 13 April 2011 (UTC): Since I will not be able to attend the meeting due to the 6 hour time difference while I am away in Hungary, I am outlining the status of my work for the previous week and questions. It would be great if something like minutes of the meeting can be added to this page or at the bare minimum of answers to my questions can be communicated here, through an e-mail or some other medium.

Prospectus
A very rough draft of my prospectus has been written. Upcoming steps
 * 1) Revisions:
 * 2) Elaboration of various points is needed. Others need to be more precise.
 * 3) A compilation of basic references, esp. in support of the latter in the previous point.
 * 4) Write an abstract
 * 5) Circulation among committee members (who should they be based on current availability?)
 * 6) Submission to Grad School: by early summer at the latest is desired.

Understanding angular distributions in gen_3pi
Work ongoing
 * Generated all waves separately with permutation of final state pions off and with an artificially narrow &rho; (~45MeV) to make identification of decay groups clear.
 * Programming errors found in bachelor pion identification
 * Angular distributions now look more reasonable, but I haven't had the chance to examine them in detail and understand the superpositions make sense.
 * Question: in "Mapping the Spectrum of Light Quark Mesons and Gluonic Excitations with Linearly Polarized Photons" Presentation to PAC30 – The GlueX Collaboration on July 6, 2006 by Curtis Meyer, page 14, Section: "Linear Polarization and Analysis": it is explained how linear polarization imprints a cos2(&phi;) or sin2(&phi;) distribution on the decay.
 * But what new information is there? Aren't we just imprinting beam polarization on the decay distribution?
 * I do see the expected cos2(&phi;) dependence when I generate from 100% x-polarized beam in superposition with a component flat in &phi;. What is the significance of this mixture (assuming I am truly 100% polarized)? Is the determination of this mixing the actual reason for "imprinting beam's polarization signature"?

Conversion to a gen_omegapipi generator
As discussed before, gen_3pi is a thin, simple front end while AMPtools do the heavy lifting. The intent seems to have been that the user write this front end according to his/her needs. So, I am trying to do this by changing the parameters for &omega;&pi;&pi; generation (and hoping that I do not need to elaborate the &omega; decay, letting HDGeant decay this particle for me)

'Immediate challenge: HDDM output has not been written yet: IU seems to have been using gen_3pi -> ROOT file -> Toy Detector -> Reconstruction/Analysis chain with HDDMDataWriter (to supplant ROOTDataWriter) last reported in January to be on their to-do list.
 * Asked Jake on the status: he says he is just writing ASCII a la genr8 and then using genr8_2_hddm
 * Attempted not to kludge and write the HDDMDataWriter class myself
 * Compilation of class is fine (done statically just like ROOTDataWriter) but then problems of "undefined reference to [hddm functions]" when compiling the generator that uses this class (it's as if it doesn't know about hddm_s.h) Similar techniques used in danahddm plugin. Is it something about the latter being a shared object unlike my static HDDMDataWriter?
 * Current situation: stuck - tempted to kludge
 * Others things to change about output: particle type info - ROOTDataWriter only outputs 4-vectors.

Other Questions

 * Status of CHESS proposal?
 * Spec'ed monochromator plates? Still time to get them cut and polished?
 * Firm dates on the CHESS run? Logistics?
 * Richard, thoughts on the Hadron 2011 abstract? (I should submit in the next few days and anyway should hurry to ask JLab for grad student travel money)