[Halld-offline] Minutes, GlueX Offine Meeting, December 14, 2011

[Mark M. Ito]

Folks,

Find the minutes at 
https://halldweb1.jlab.org/wiki/index.php/GlueX_Offline_Meeting,_December_14,_2011#Minutes 
and below as text.

-- Mark
_____

GlueX Offline Meeting, December 14, 2011

Minutes

Present:
* CMU: Will Levine, Paul Mattione
* FSU: Nathan Sparks
* IU: [attempted to connect via EVO, connection made by chair too
late!]
* JLab: Eugene Chudakov, Hovanes Egiyan, Gagik Gavalian, Nerses
Gevorgyan, Mark Ito (chair), David Lawrence, Dmitry Romanov, Sascha
Somov, Simon Taylor, Elliott Wolin, Beni Zihlmann

Announcement

* Elliott announced that documents on the configuration database and
the conditions database are soon to appear on the DocDB.

Review of minutes from the last meeting

We went over the [29]minutes from the November 30th meeting.
* David and Will reported that we are ready to make the 1-2-3-4
scheme for BCAL read-out the default. One of them will do the deed.
* David has a working system for reading EVIO format in the JANA
framework. Find it in the FCAL beam test area of the Subversion
repository. It creates JANA objects out of FADC data. He has also
been working on an event viewer and a histogramming plug-in to
support the test. There is some documentation linked from the
[30]FCAL test wiki page.
* The [31]too-many-photons thing is still an outstanding issue.

A CLARA-based analysis system

Gagik gave us an overview of his system for doing physics analysis from
a [32]HDF5-based DST data set using Hall B's CLARA system. He gave a
[33]presentation and a live demonstration using an installation of the
system at Old Dominion University. Multiple processes can work in
parallel to create data objects, an n-tuple in his demo, and ship said
objects over the network to the user. Python-based tools can receive
the data and create graphical output for the user.

CCDB update

Dmitry gave us an update.
* CCDB has been installed on the ifarm at JLab
* installation is fully functional, including a JANA plugin
* documentation is coming!
* the web application is held up by system software compatibility
issues

Reconstruction sub-group reports

Tracking

Simon described [34]a proposal for monitoring performance of tracking
on single particles. He has developed a set of scripts and ROOT macros
that will allow us to see how the tracking is doing in the simplest
situation, as time goes on and the code continues to develop. We will
likely run the package twice a week, like the "b1pi" job already
implemented as a cron job.

He calculates and displays particle reconstruction efficiency and
momentum resolution in various views. Other plots can be added to the
package; please send your suggestions to Simon.

While looking at the plots, we discussed some of the features in the
tracking results that have been known for a long time, in particular
why a "1%" confidence level cut has poor efficiency in some regions of
phase-space. Eugene pointed out that we need to find out whether these
are for physics reasons in the reconstruction (e. g., large
single-scatters), problems in the pattern recognition (hits being
missed), or in the track-fitting itself. We will convene a smaller
group to discuss a strategy for answering these questions.

PID

Paul gave us an [35]update on particle identification using drift
chamber dE/dx. He has added kaons to the study and has gone on to plot
the various means and sigma's as a function of momentum so that one can
judge the degree of π/K/p separation. Confidence levels for all
quantities look extremely flat.

Eugene wondered if delta ray production was simulated as a separate
electron track. He thought that it was important to do so for this type
of study. Paul will check on this and look for differences if this was
not done before.

Memory leak in the reconstruction?

Will agreed to summarize the problem, first report at the morning GlueX
meeting, and send email to the group.

Proton reconstructions studies

Sascha showed [36]results of studies where he looked at reconstruction
efficiency and kinematic resolutions and biases for the recoil proton
in both γp→pη and γp→pπ^0 events. He sees rather large inefficiencies
for protons when a χ^2 cut is applied. These are likely due to
non-Gaussian tails in the reconstructed quantities. The source of these
tails will have to be studied.

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References

29. 
https://halldweb1.jlab.org/wiki/index.php/GlueX_Offline_Meeting,_November_30,_2011#Minutes
30. https://halldweb1.jlab.org/wiki/index.php/2011_Hall_B_FCAL_Beam_Test
31. 
https://mailman.jlab.org/pipermail/halld-offline/2011-November/000797.html
32. http://www.hdfgroup.org/HDF5/
33. https://halldweb1.jlab.org/talks/2011-4Q/HallB-DataMining.pdf
34. 
https://halldweb1.jlab.org/wiki/index.php/Proposed_automated_single-track_diagnostics
35. https://halldweb1.jlab.org/wiki/index.php/Mattione_Update_12142011
36. https://halldweb1.jlab.org/wiki/index.php/Recoil_proton_reconstruction