[G12] Minutes from 3/31/2010 meeting

[Craig Bookwalter]

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

http://clasweb.jlab.org/rungroups/g12/wiki/index.php/30Mar10#Minutes

and pasted below:


  30Mar10


       From G12_wiki

[edit 
<http://clasweb.jlab.org/rungroups/g12/wiki/index.php?title=30Mar10&action=edit&section=1>]


    Agenda

    * Update on flux/sync
          o Gflux and tripfixer results
            <http://clasweb.jlab.org/rungroups/g12/wiki/index.php/Gflux_and_tripfixer_results>

    * mysql problems?
    * Momentum corrections(?)
    * Omega Cross section

    * Analyses status:
          o eta pi- Delta++ Diane
          o pi+ pi+ pi- Craig
            <http://clasweb.jlab.org/rungroups/g12/wiki/index.php/Charged_3pi>

          o K+ K- (X) Mukesh [Phi Eta
            <http://clasweb.jlab.org/rungroups/g12/wiki/index.php/Strangeonia>]

          o Cascades Johann
            <http://clasweb.jlab.org/rungroups/g12/wiki/index.php/Xi>
          o Kaons Will/Mike
            <http://www.jlab.org/%7Esalgado/g12pkk/pkkRES.pdf>
          o KKpi Miles
            <http://clasweb.jlab.org/rungroups/g12/wiki/index.php/Miles_Price#Physics_Analysis>

          o Delta++ 3pi: Paul
            <http://clasweb.jlab.org/rungroups/g12/wiki/index.php/Delta-3pi>


[edit 
<http://clasweb.jlab.org/rungroups/g12/wiki/index.php?title=30Mar10&action=edit&section=2>]


    Minutes

    * Mike P. x 2, Valery, Carlos, Will, Johann, Diane, Craig, John P.,
      Ben, Sasha S., Paul E., Mukesh, Sasha O.
    * Diane updated the progress on gflux -- she's finished processing
      60K files of 63K. We currently have 1.05e14 photons across the
      whole tagger in those 60K files, and 1.5e13 photons above 4.4 GeV.
      This is equivalent to about 40 pb^-1, a factor of 10 over g6c, but
      not the factor of 20 quoted in the proposal. Sasha will try to
      adjust the total number of photons by the statistics produced by
      tripfixer, also quoted on the link in the agenda. Diane will also
      try to get an estimate for the range 4.8-5.4 GeV.
    * The MySQL problem observed at FSU seems to be related to using
      libmysqlclient.so.16 -- Johann reports sporadic behavior
      connecting to the CalDB, and at FSU we cannot connect at all.
      However, when libmysqlclient.so.14 is used (the default for
      RHEL5), FSU observes no problems connecting to the CalDB. This may
      be a forward-compatibility problem.
    * Momentum corrections are moving forward--Johann has volunteered to
      help Craig and has already written code to do the tagger energy
      corrections derived by the kinematic fitter. Craig is working on
      getting statistics to fill out all the bins included in the g11
      momentum correction. He may use a number of other runs around
      56855 to build statistics.
    * Craig has heard nothing from the student at CMU who was supposed
      to produce some omega MC for the cross section. Craig would like
      to just use genr8 to get a first-order acceptance
      correction--there were no objections.
    * Diane reports that she produced a skim for Dennis with all of her
      cuts. He is trying to get gamp to work on her data.
    * Mukesh is currently skimming data and is experimenting with two
      gammas in the EC. He has reproduced Diane's results, seeing a
      large pi0 peak in the 2-gamma invariant mass, but no eta as yet.
      Diane says that he will need to do some angular cuts before he
      will be able to see the eta at all in 2gamma.
    * Johann has completed some studies on recalculating his invariant
      mass spectra with one of his kaons set to be either a pion or a
      proton. He sees some indication of sigma pi events (present when
      one of the pions is misidentified as a kaon), but no evidence of
      K+ lambda events (which would be present if protons were being
      misidentified as kaons). He also reports that the issue of
      magnetic field in gsim, to his estimation, was resolved by
      examining the neutron in Craig's 3pi data after changing the
      magnetic field to center the sigma mass on the PDG value -- the
      neutron was shifted by 20 MeV from the PDG value. Mukesh mentions
      that when you run a skim program linked against the CLAS
      libraries, it prints to the screen a torus current of 1920A, when
      we ran at 1930A...worrying. Mukesh is going to look into this.
    * Carlos shows some plots from pKK with 98% of the data, but the
      phi-eta and phi-pi0 masses don't have a lot of visible structure.
      Carlos will look into using gammas from the EC like Mukesh to see
      if he can clean them up. The exclusive pK+K- is even more
      interesting: no 1680 in the KK mass spectrum, an unidentified bump
      at 1325 or so...
    * Paul shows some plots from an analysis of gamma p -> p pi+ pi+ pi-
      (pi-) with 1% of the data--it seems that the delta++ sucks up all
      of the baryon production and leaves the 3pi system fairly clean.