[G12] Minutes from 4/14/2010 meeting

[Craig Bookwalter]

Howdy folks,
   Minutes from today's meeting can be  found at:

http://clasweb.jlab.org/rungroups/g12/wiki/index.php/14Apr10

and pasted below:


  14Apr10


       From G12_wiki

[edit 
<http://clasweb.jlab.org/rungroups/g12/wiki/index.php?title=14Apr10&action=edit&section=1>]


    April 14, 2010 Agenda

    * Omega cross-section update
      <http://clasweb.jlab.org/rungroups/g12/wiki/index.php/Rough_omega_cross-section_calculation#Rotten_t-counter>

    * Paul: Delta++ [1]
      <http://clasweb.jlab.org/rungroups/g12/wiki/index.php/Eugenio>
    * Momentum corrections
          o Heghine
            <http://clasweb.jlab.org/rungroups/g12/wiki/index.php/Momentum_Corrections_4>

    * Diane: eta pi- Delta++
      <http://www.jlab.org/Hall-B/secure/g12/dschott/April14.pdf>
    * 3pi update
      <http://clasweb.jlab.org/rungroups/g12/wiki/index.php/Charged_3pi#GSIM_T-slope_study>

    * Mukesh pKK(X)
      <http://clasweb.jlab.org/rungroups/g12/wiki/index.php/Strangeonia>

[edit 
<http://clasweb.jlab.org/rungroups/g12/wiki/index.php?title=14Apr10&action=edit&section=2>]


    Minutes

    * Attending: Craig, Dennis, Carlos, Mike P. x 2, Will, Heghine,
      Diane, Valery, John P., Ben, Mukesh, Sasha
    * Craig asks for guidance about what to do with the questionable
      tagger t-counter in calculating the omega cross section. Dennis
      suggests to cut it out. Craig also will examine the
      t-distribution, angular distributions and Dalitz plots of the
      omega in g12 as well as the raw MC that was used in the g11 omega
      analysis.
    * Heghine shows the latest iteration of momentum corrections using
      the e6 algorithm. Dennis raises the question of who really needs
      momentum corrections. Craig and Diane are not so concerned with
      corrections on the order of a few MeV. Mike Paolone and Johann may
      care about these corrections. Dennis proposes to include Heghine's
      momentum corrections in clasEvent--Mike and Dennis will write the
      function and Johann will check it. Craig will continue with his
      corrections for the time being, but if Johann gets a good enough
      correction from Heghine's code there will be no need to continue
      with other paths.
    * Diane shows updated analysis plots from last time with a low-t cut
      in place to try and remove her baryon background. Requiring |t| <
      0.5 cleans a lot up but her yield drops to 4000 events or so out
      of 90+% of the data. Dennis suggests there is nothing stopping her
      from doing a PWA on those events, with just P and D waves in m=+1,-1.
    * Craig shows a plot of the way GSIM modifies a t-slope. Basically
      GSIM will reduce an input t-slope to 66% of its original value.
    * Mukesh shows a number of plots from pKK. After the phi cut, his
      eta sits atop a lot of background. Unfortunately in pKK, the eta
      doesn't get enough boost to put both gammas into the EC. Dennis
      suggests selecting events with a single gamma, and then looking at
      the missing mass and missing momentum off of pKKg -- the missing
      mass should be zero but the missing momentum should be nonzero.
      Dennis would also like to see a selection on t. Extended
      discussion ensues on the reasons why a phi-pi0 resonance is exotic
      or at least unusual -- mostly because it violates isospin
      conservation. It seems that if you have a delta in your final
      state in this channel you should get many more phis, just from
      looking at the decay modes in the PDG.