[Halld-offline] Minutes, GlueX Offline Software Meeting, November 30, 2011

[Mark M. Ito]

Folks,

Find the minutes at 
https://halldweb1.jlab.org/wiki/index.php/GlueX_Offline_Meeting,_November_30,_2011#Minutes 
and below as text.

-- Mark
_____

GlueX Offline Meeting, November 30, 2011

Minutes

* CMU: Will Levine, Paul Mattione, Curtis Meyer
* FSU: Nathan Sparks, Beni Zihlmann
* JLab: Mark Ito (chair), David Lawrence, Yi Qiang, Dmitry Romanov,
Simon Taylor

Announcements

* David told us that that decision on the segmentation of the BCAL
read-out should be made soon. After that we should put the
decided-upon segmentation into the reconstruction. Until now we
have been running with "fine" segmentation. Smearing code will have
to be updated.
* David also commented that the FCAL beam test gives us an
opportunity to develop code to read in EVIO format into the JANA
framework.
* Dmitry on the CCDB:
+ He mentioned that Python 2.7 is now installed on the ifarm
machines, a prerequisite for the CCDB shell. He will start
work on installing a version that works there, for public
consumption.
+ He noted that the difficulties noted last time with table
column names have been finessed.

Reconstruction sub-group reports

Calorimetry

Matt Shepherd reported via email:

[With regard to] Beni's email regarding high increase in photons, I
know Will had been checking in some changes to the BCAL code;
however, I thought that all of his changes were in my reconstruction
algorithm, which, as I understand it, is not the default. As far as
I know, no one has made any changes to the FCAL reconstruction.

Will mentioned that he is putting together a report/summary of his
changes to the BCAL code.

Tracking

Simon reported an increase in the number of reconstructed π^+'s, π^-'s,
and protons by 10-20% due to recent changes.

PID

Paul had continued work on the particle ID using drift chamber dE/dx.
See [37]his wiki page for details. He has essentially calibrated the
Monte Carlo dE/dx responses, measuring the mean and variance in dE/dx
and uses those measurements in forming a χ^2 statistic. He gets
dramatically improved confidence level distributions as a result.

Too many photons

Last Monday Beni [39]reported a change in the semi-weekly b1pi
reconstruction job where the number of photons reconstructed increased
by about 20%. The increase comes mostly in the forward region. The
change occurred between 14th and 21st of November.

There was some speculation about what might have occurred, but no firm
conclusions about the cause. David pointed out that changes in charged
particle tracking can affect the photon yield but the increase in
reconstruction efficiency that Simon reported earlier naively goes the
other way; better tracking would identify more clusters as "charged"
and thereby reduce the number of photons. More work is needed.

Mark mentioned that if we had suite of tests that looked at things at a
lower level, these issues would be easier to understand. Relevant in
this case would be, for example, the raw number of clusters, both
"neutral" and "charged" or even the raw hit multiplicity and energy
distributions. Developing a set of tests like this is a possible
project for this working group.

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References

37. https://halldweb1.jlab.org/wiki/index.php/Mattione_Update_11302011
39. 
https://mailman.jlab.org/pipermail/halld-offline/2011-November/000797.html