Minutes of the Jefferson Lab CLAS Collaboration January (25-27), 2001 Next meeting: June 7 - 9, 2001 at Jefferson Lab, CEBAF Center For you to do: 1) If you are the spokesperson for an official experiment, or if you are doing an individual analysis of CLAS data, finish your Annual Progress report for the laboratory by February 5th. The template is attached at the end of these minutes. See below for details. 2) Save the dates for the next CLAS meeting, given above. ________________________________________________________________________ About 80 members of the CLAS Collaboration met for the three-day winter meeting at CEBAF Center. CLAS is in the midst of a very productive and long run of the eg1(2000) experiment, running with high polarization electron beams on polarized NH3 and ND3 targets. There have been no major breakdowns of Hall B equipment since the last meeting. Here are some numbers that characterize where we are: Since the last meeting in September, one publication (our first) has a appeared in PRL, another has been accepted by PRL, and one has been submitted to PRC. All of these physics publications are available on our web site. Three instrumentation (NIM) papers were accepted since the last meeting. During the meeting we counted ten physics analyses that are approaching the publication stage, meaning that they will be submitted (or be close to submission) by the time we meet again in June. The Collaboration has 82 identified analysis projects, most of them with data in-hand to work with, 47 graduate students, 8 completed PhDs, and there are 10 post-doctoral researchers on site from outside user groups. When the eg1 runs end in April the CLAS program will have used 267 of 405 days of approved beam time since data-taking began. Jeopardy Review --------------- The Hall B program will face its first beam time jeopardy review by the PAC in July of this year. The purpose of this review is to justify the remaining beam time in the program in light of developments in the field. A plan for how this will be done was presented by the Chairman for Collaboration input. The plan was worked out among Larry Cardman, Bernhard Mecking, Reinhard Schumacher, and several other people. Since CLAS experiments are mostly organized by "run groups", the review will be by run groups. Stand-alone experiments will be reviewed individually. Hall B does NOT have the very large backlog of experiments that the other halls had; depending on some of the counting details, we presently have between a 2.5 to 3 year backlog. Larry Cardman has decided that ALL of the beam time that comes up for jeopardy review MAY be re-approved on scientific merit. This is true as long as the PAC is not inundated with new beam time requests. The operative formula for the summer PAC will be that "100% + 45 days" is available for distribution. The plan calls for the jeopardy review to be split into two sessions, PAC 20 in July '01 and PAC 21 in January '02. In the first round the review will include several specialized-setup experiments: eg1/photon: 91-015 Helicity Structure of Pion Photoproduction g7/94-002 Protoproduction of Vector Mesons off Nuclei e1/93-043: Measurement of the Delta-Delta Component of the Deuteron by Exclusive Quasielastic Electron Scattering e6/94-102, 94-019 (Deuteron experiments) (may be on '02 schedule in time to excape review) In addition, the entire e1 program (run group) would be reviewed. The second round of experiments would include g1, g2, and g3. The PAC will not review experiments that are on a run schedule and are scheduled for their complete remaining time. It remains to be determined whether the e2, the e6 deuteron experiments, or the g2 and g3 experiments will be on the tentative 2002 schedules in time to avoid this review. Also, the PAC will not review experiments whose beamtime has been completed previously, which includes eg1/electron, g5, e5, and g6. The PAC presentations for the run groups will include an overview talk which highlights accomplishments of the run group, especially those analysis efforts which will not give detailed presentations. Then one or two "lead" experiments will motivate the need for the additional beam time. The run groups will be allowed to ask that their remaining beam time be redirected to updated running conditions They can also ask for additional beam time, but since this affects the whole CLAS program, requests for additional beam time must first be proposed and approved by the Collaboration. The run groups were asked at this meeting to identify their coordinators for this review. The e1 group appointed V. Burkert, P. Stoler, L. Elouradrhiri, D. Carman, and R. Minehart to this job. The g1 group will have W. Briscoe coordinating the work. The g2 group will have P. Rossi in charge. The g3 group will have B. Berman in charge. Annual Reports -------------- The Lab have asked all Spokespersons to submit a multi-page annual report contributions on their work. We decided to appoint CLAS members to write overview descriptions of the run groups. This is to avoid redundancy in the individual contributions from the members. These persons should also act as editors to streamline, as needed, the contributions. The appointees are: e1 Volker Burkert e2 Stepan Stepanyan & Larry Weinstein e5 Mike Vineyard eg1 Sebastian Kuhn g1 Bill Briscoe g2 Patrizia Rossi g3 Barry Berman g5 Barry Berman g6 Jean Marc Laget g8 Phil Cole These people are only writing the OVERVIEWS. Each member who is doing an analysis is asked to write up a summary of his or her analysis project. This is not restricted to "official" experiments only. Any CLAS analysis effort, whether "individual" or "CLAS Approved Analysis", or even projects pending beam-time are asked to write a short report. Please put your contribution in the CLAS secure web-site directory under your run group's heading, or e-mail it directly to the relevant person above (if your postscript figures won't gag his or her email system). Recall that the Latex template were were asked to use was sent to us on December 22nd. [I have attached a copy to the end of these minutes in case you didn't get one.] Do this by February 5th. [I trust the persons listed above will submit the consolidated results to the Lab by the deadline one week later.] CLAS Approved Analysis ---------------------- At this meeting the Collaboration heard, discussed, and voted on three proposals for "CLAS-Approved Analyses". These were the first proposals to undergo CLAS internal review and vote under our CAA policy. Recall that the purpose of CAA's is to establish formal recognition of an analysis project that will not go before the PAC because it is based upon already-taken data. It allows collaborators to demonstrate that they have the support of the whole group, which may be important in their efforts to attract funding or students. At this meeting we heard three CAA proposals: S. Stepanyan Deep Virtual Compton Scattering at 4 to 5 GeV Using CLAS J. Kellie Photoproduction of Associated Strangeness using a Linearly Polarized Beam of Photons N. Pivnyuk Production of hadronic systems near threshold in eA interactions at high momentum transfer Each of these proposal was voted upon by full and term members by secret ballot. They all were passed by the necessary 2/3 majority. Other Notes ----------- Dennis Weygand presented a request which will be made to the PAC next week for an extension of the g6/99-005 beam time of 6 days. This would bring the total time to 10 days. Combined with improved beam intensity, torus setting and DAQ performance, the run would net about 10 times more data than now exist for meson searches. By hand vote, the extension was approved as a full CLAS effort: ~40 yea, ~0 nay, ~4 abstain. In the plenary sessions, very interesting physics talks on advanced analyses were given by John Price, Cole Smith, Kyungseon Joo, Steve Barrow, Marco Ripani, Bin Zhang, Matthieu Guillo, Robert Feuerbach, John McNabb, Ken Hicks, and Alex Stavinskiy. [These talks will not be recounted or summarized here: there was so much information in these talks it is impossible to capture fairly, and these minutes are long enough already! There are several drafts of papers in the pipeline for publication. The Collaboration may expect more calls from the Chairman and/or the Working Group leaders in the next few weeks and months with requests that people serve on review committees. [We note that the SoN and the Real Photon working groups have decided to approve analysis results using appointed subcommittees to probe the details of a given work. These Working Group subcommittees are NOT replacements of the Collaboration-wide Ad Hoc committees that are appointed by the CCC. Thus, we have evolved into a structure where each paper is being reviewed twice, essentially, before it goes to the full Collaboration for comments. Note that these reviews are not intended to be private or exclusionary. If you want to help out, feel free to volunteer. The process we have is intended to reduce the total workload on the Collaboration.] Hardware, Software, Infrastructure ---------------------------------- Dieter Cords reported on continuing impressive gains in performance of the Data Acquisition system. It now can acquire data up to about 4000/sec (up from about 3000/sec) with a smooth dead-time behavior as a function of rate. The newest improvements were made possible by "microprogramming" the SFIs such that the front-end readout time was reduced from 250 microseconds to 100 microseconds. This work was done largely by Vardan Gyurjyan. The present limit in the system the rate of writing data to disk, at about 24 Mbyte/sec. Also, there is now a more sophisticated and faster structure for on-line event filtering and reconstruction, for things like monitoring the target polarization from actual scattering data. Mark Ito discussed the offline situation. There are now 125 nodes on the farm. The farm has been idle for data cooking some time, but via the introduction of a new lower-priority queue it has been used to generate GSIM data for the e2 group. A big change-over to the new calibration database (Cal DB) was presented. This new database structure will replace the Map Manager that has been used for the last three years. The new Cal BD will be the calibration database of record starting MONDAY January 29th. The official Map will be copied over into the Cal DB and then made "readonly". Users of the cooking codes will have to relink their codes using new libraries which will transparently change all Map calls to Cal DB calls. Conversion scripts like "map2db.pl" and "db2map.pl" are available for people who want to continue working with private copies of the Map Manager for the time being. There seems to be a mind-boggling about of disk-space available now. Mark introduced the notion of DST disks which are permanent storage space for up to 6 Terabytes (lab wide?) of DST data. He proposed that each CLAS run group that requests it may get 200 Gb of space. Mark advocated revisiting the issue of offline code management. He pointed out that run groups manage their own affairs, but the calibration and cooking software that they have in common is not being managed by anyone with designated responsibility or authority. This has led to fragmentation of codes and lowered efficiency in the calibration and cooking of CLAS data sets. The documentation is out of date, and the codes are hard to use. Expert knowledge is lost when certain graduate students or staff move on to new jobs. Suffice it to say that many opinions were aired. It is fair to say that there is indeed a problem with our offline code organization, but the real issue is what can be done to solve the problem. These questions were again brought up for discussion on Saturday afternoon as part of the Coordinating Committee report, where once again many opinions were aired. Discussions are sure to continue. Mac Mestayer reported on two items in "tracking distortions" due to magnetic field and/or alignment. Studies of how the magnetic field model affects data quality have led to the adoption by g1c of a hybrid field map which is 67% "new" (computed using the improved coil geometry) and 33% "old" (what every run period has used for cooking up to the present time). This work was done by a number of people including Gordon Mutchler and Eugene Pasyuk. In Gordon's case, he studied the reconstructed hyperon mass as a function of angle to find the "best" field mixture. It was in rough agreement with what Mac found with Konstantin when looking at reconstructed beam momentum via two methods. Eugene found that a larger number of tracks were found by time-based tracking with the improved field map: in the neighborhood of 4% for negative hadron tracks. Most of the gains were at the edges of the acceptance in theta and phi, but they also showed a slight unexplained phi dependence. Volker Burkert warned that the improved field has not been studied carefully for electron tracks. Peter Heimberg reported in photon normalization issues. He concluded that most data sets have run-to-run normalization consistency at the level of 2-3%, while the absolute normalization uncertainty ranges at the present time from 2% (g5) to 20% (g2). Arne Freyberger reported on new beamline instrumentation, especially related to monitoring the helicity-dependent charge integrals seen by the experiments. There are now four monitors of beam intensity: (1) a synchrotron light monitor at the bend into the hall. This is very stable and tracks the Faraday cup with very good linearity. It will be useful to use this as a flux monitor during photon runs. (2) (3) There are two Optical Transition Radiation detectors which look at backward light scattering from a 0.8 micron aluminum foil which sits in the beam. One is used only for Moeller runs. The other also tracks the Faraday cup very well. (4) The Faraday cup has improved electronics so it can integrate the beam flux at the 30 Hz rate at which the helicity flips. It is calibrated so that one "count" corresponds to 675k electrons (!). Run Status Updates ------------------ Sebastian Kuhn reported on the eg1 run which is in progress. Compared to the first eg1 run, the target polarizations have been better, as has the rastering of the beam on target. He showed impressive results of the first-ever measurement of quasi-free scattering of electrons from a pure Nitrogen-15 target which showed clear differences relative to a carbon target, especially in the higher W region. This is important for doing background subtraction or dilution-factor calculations for the NH3 or ND3 runs. Dan Sober discussed the recently-organized measurement of the GDH sum-rule asymmetry in the 2.5 to 4 GeV energy range. The measurement would fill a gap between the soon-to-be-taken data at Bonn and SLAC. It is believed that CLAS, which was not designed as a 'total cross section measurer' can nevertheless capture about 85% of the total hadronic cross section. This few-day run was in progress during this collaboration meeting. Dave Tedeschi reported on the readiness of the g8 group to run using a LINEARLY polarized photon beam created using coherent bremsstrahlung. The goniometer has been tested and works, and the (optional) pair polarimeter has also been tested and shown to work; it will be calibrated at Spring-8 in Japan in two months. Volker Burkert reported on preparations for the e1 run at 6 GeV. Run conditions were reviewed. The main open question in whether it would help to move the target on CLAS upstream by roughly 1 meter, for which the acceptance for various channels would increase by a factor of 2. Studies of Moeller background and tracking issues are in progress. Luminita Todor declared that the Pass_1 cooking of the g1c data set has begun. She showed a number of graphs that showed the excellent quality of the data. Ken Hicks showed some plots of the status of the e1d calibrations. Lots of work remains, but progress is being made. On Saturday the Chairpersons of the Physics Working Groups gave summaries of the PWG meetings; we will not summarize the summaries here. Membership ---------- We are pleased to welcome Harout Avakian into his new role as Hall B postdoctoral research staffer. Harout was formerly working for the Frascati group, and will now be working with Mark Ito on offline software issues. The full membership application for Franz Klein, former JLab staff person and now Assistant professor at Florida International University, was presented by Kevin Giovanetti. Franz is deeply involved with the g8 (linearly polarized photons) run group, as well as the omega analysis. A vote was held and Franz was elected as a full member. [Congratulations Franz, we can't live without you.] Kevin Giovanetti discussed database issues related to the CLAS authorship lists. We now have a stabilized system for generating the starting author lists for any given run period. Talks ----- Jean-Marc Laget, chairman of the CLAS Speaker Committee, reported on recent trends in invited and contributed talks. A total of 115 invited and contributed talks have been given by a total of 60 speakers. We saw that the CSC is actively soliciting CLAS talks at major conferences and at APS meetings. We were reminded that all talk invitations to conferences must be given to the CSC for approval, and that the procedure for doing this is well documented on the web page maintained by the CSC. The main meeting adjourned at about 5:30 on Saturday with about 30 tough survivors still in the room. Any changes, additions or other clarifications of these minutes by the Collaboration members will be cheerfully considered. Amended minutes will be sent out only in case of egregious errors or omissions. [...]=chairman's editorials ------------------------------------------------------------------------- % *********************LaTex Template******************* \documentclass[12pt]{article} \usepackage{epsfig} % \newcommand{\simlt} % {\ifmmode { \raisebox{-.4em}{$<$}\atop\sim} % \else {$\raisebox{-.4em}{$<$}\atop\sim$} % \fi} \baselineskip=18.0pt \parskip=12.0pt \parindent=2em \begin{document} \subsection{YOUR EXPERIMENT NUMBER} \vspace{\baselineskip} \centerline{YOUR EXPERIMENT TITLE} \centerline{SPOKESPERSONS and COLLABORATION INFORMATION} % do NOT list all members of the collaboration - that information will remain available on the website % If you want to include defined symbols etc., please do it in the style of % the \simlt (simlt) command example above - ie, by using ``newcommand". % All figures should be referenced in the style of % Figure~\ref{fig:YOURFIG}, where YOURFIG is the name given to the figure in its label % If you have an embedded figure (preferable), use: % \begin{figure}[htb] % \centerline{\epsfig{file=YOURFIG.eps,width=DESIREDWIDTHcm,height=DESIREDHEIGHTcm} % %Use "angle" = 90 to rotate figure if necessary % \caption{This is a really beautiful figure.\label{fig:YOURFIG}} % Note that for proper referencing the label should be "inside" the figure caption % \end{figure} % If embedding doesn't work, simply reserve space for a figure as follows: % Use the standard \LaTeX\ commands % for beginning a figure, leaving vertical space, captioning, and % referencing as in this example. % \begin{figure} % \vspace{2.5in} % \caption{A sample figure; in this case 2.5" is adequate for both the % %figure and a reasonable margin above and below it.\label{fig:sample}} % \end{figure} % If you want to include any tables please use the \LaTeX\ table % environment, and reference the tables using the same style shown in this % file for figures, but substituting ``tab:tablename" for ``fig:figurename" % in the label statement. % The use of references should be in the ``Nuclear Physics" style, where we % will refer to a reference by the first two letters of the first author's % name, followed by the year of publication. Hence, we would % cite~\cite{Do92} for a paper by John Doe printed in `92. All bibliography % entries should be in the style of the example at the end of this file. % Private communications should be referenced as in the example for J. % Smith~\cite{Smpc}. \subsubsection{Introduction} % Your text describing the experiment and its goals \subsubsection{Experiment Status} % Your text indicating the status of the experiment % (\% data taken, information on operational parameters such as target and/or beam polarization, etc.) \subsubsection{Results - or Expected Results} % Your text on the physics results obtained to date, on further information expected, % on the quality of data obtained and/or final errors anticipated, etc. \begin{thebibliography}{MM99z} % Please include a blank line between each reference as % in the examples below % \bibitem[Do92]{Do92} J. Doe, , {\em et al.}, Journal of Irreproducible % Results {\bf B44}, 259 (1992). % \bibitem[Smpc]{Smpc} J. Smith, private communication. \end{thebibliography} \end{document}