Jefferson Lab > Physics > Program Advisory Committee
Privacy and Security Notice

Program Advisory Committee (PAC)


March 6, 2007

Dear Jefferson Lab User,

PAC32 will continue with the planned annual call for proposals for 12 GeV science and user commitments to the construction of experimental apparatus that began with PAC30. Once again, we will be focusing on the detailed consideration of proposals and letters of intent for the science that will be the focus of the first five years of running with the Upgrade. It continues to be critical that we identify as quickly as possible the intended contributions of the Jefferson Lab user community to the construction of the "base equipment" experimental apparatus that will be constructed as part of the Upgrade project. While the out year profile for 12 GeV construction funds will evolve with each fiscal year budget determination, it is clear that these user commitments must be identified for the CD-2 decisions in 2007 that are the next formal step for the project. This effort will be the focus of PAC32.

We recognize that the development of the full complement of experiments for initial running with 12 GeV beams will take several years of planning and review. PAC32 will continue our focus on the part of the Upgrade's physics program that can be carried out using the base equipment for the Upgrade. Specifically, it will only review proposals in which the proposing scientists and institutions state clearly their intention to participate in and contribute to the construction of that base equipment. Commitments made as part of proposals to PAC30 may be included as part of the commitments identified for PAC32 proposals, but each new proposal must include the following items:

From groups that made commitments toward the base equipment construction in proposals accepted by PAC30:

From groups that did not make a commitment toward the base equipment construction in a proposal accepted by PAC30:

Note that the base equipment includes all devices included explicitly in the 12 GeV Upgrade Project Conceptual Design Report: CLAS12, SHMS, GlueX, the upgraded electronics for the Hall A HRS and all experimental-Hall-specific 12 GeV beamline device upgrades.). Future 12 GeV PACs (we estimate there will be at least one per year for the next few years) will flesh out the research program in greater detail and consider proposals that require the construction of new equipment that is not part of the formal Upgrade construction project. Future 12 GeV PACs will also consider experiments to be done in the 12 GeV era with all available energies and all available experimental apparatus.

We will insist (as we did for PAC30) that proposals to this particular PAC, to the extent possible, focus on experiments using only the base equipment itself. We recognize that some may require use of existing secondary devices and will accommodate such proposals so long as the modifications needed are truly modest and the proposing scientists will undertake the funding and realization of those modifications in addition to their contributions to the base equipment construction. We will not accept at this PAC any proposal or letter of intent requiring major apparatus that is not part of the base equipment. If you have questions about the suitability of your proposal for this PAC or future 12 GeV PACs, please contact Larry Cardman directly.

As was the case at PAC30, we will give more serious consideration than usual to letters of intent for this PAC so long as they are relatively well developed scientifically and the intended contributions of the proposers to the construction of the base equipment are clearly identified. A letter of intent that receives a strong endorsement by PAC32 will be treated in a manner analogous to how deferred proposals have been treated traditionally - i.e. it will have established a claim on the physics measurement but must be upgraded to an approved proposal by resubmission to the PAC as a full proposal within two PACs. Note that this is a change from the PAC30 "rules" - we are extending the time of validity of a recommended Letter of Intent to two PAC meetings, and this means for now to two years. We are also hereby extending the "established claim" period for PAC30-recommended Letters of Intent for a second year (i.e. a full proposal need not be submitted until PAC34).

As all three halls have a significant backlog of proposals for physics to be done prior to the shutdown for installation of the 12 GeV Upgrade hardware, PAC32 will NOT consider proposals using the lower energy beams now available. Such proposals (and continued jeopardy review of previously-approved proposals) will be the subject of PAC33, to be held early in 2008.

PAC32 will be held during the week that begins August 6 (about a month later than usual) to maximize the time available for proposal preparation. Proposals for PAC 32 are due at Jefferson Lab by the close of business on Wednesday, June 20, 2007. As is the established tradition, the JLab Technical Advisory Committee (TAC) will make comments on the technical viability of the proposals and provide these comments to the spokespersons and the PAC prior to the meeting. As always, proposals will be judged on the quality of the physics, technical feasibility, and the ability of the group to carry out the proposed measurements.

The PAC will not have a specific allocation of beamtime. It is our intent that the PAC process over the next five years will identify the initial physics program for the upgrade. The PAC will be requested to determine whether the proposals presented identify physics that in their opinion belongs in the first five years.


Because we want to focus this PAC on 12 GeV physics, we have suspended Jeopardy review for this PAC. Any "6 GeV" experiment currently on the books and up for Jeopardy review will be given an additional 6 months time prior to such a review.


New Proposals

New proposals requiring beam energies up to 12 GeV (for Hall D, and 11 GeV for Halls B and C) will be reviewed by PAC 32. It i s highly recommended that you consider the guidelines below (developed for the "standard" PAC proposals) when preparing your proposal:

  1. Be careful to submit a complete package that can stand alone. Do not assume that the PAC is aware of information contained in previous proposals, technical notes, and letters of intent. If this information is important background for your proposal, be sure that you include it in the proposal, for example as an appendix.
  2. Give justification for the uncertainty of the final results. Give realistic estimates of uncertainties in resolution, absolute momentum and angle calibrations, random coincidences rates, etc. and indicate how these impact the final results.
  3. Be sure to include a detailed table showing how you calculated the number of days requested. Since run time is a very scarce resource, the PAC reviews very carefully the details of the request, makes its own calculation, and allocates the time accordingly. Therefore it is essential to give a full and detailed justification of your request.
  4. Include experimental details and simulations. Complex and challenging experiments often require extensive justification and simulation calculations. Discussions of yield, backgrounds, and projected statistical and systematic errors, are essential elements in the justification. To support these, it is important to give the results of simulation calculations that should be the basis of the experimental design. This is an essential component of the package required in order to get such proposals approved.
  5. Indicate how the project relates to other approved proposals still "on the books" for the 6 GeV program. The PAC and the Laboratory have specifically asked proponents of new proposals to clearly state how their experimental goals are addressed by other approved experiments at the Laboratory. As stated in earlier PAC reports, failure to pay sufficient attention to this charge can result in the PAC not considering the new proposal until the information is provided.

Experiments with Similar Physics Goals

On your proposal cover sheet indicate any existing approved, conditionally approved, or deferred experiments that have physics goals similar to those in your proposal. In the text of your proposal, compare and contrast your proposal with respect to these proposals and experiments already considered or under consideration by previous PACs. Note that both one-page summaries and the full text for most proposals are available on-line at You may also contact User Liaison (see below) for copies of proposals.

The spokespersons for the experiments and proposals you have listed on your proposal cover sheet will receive copies of your proposal prior to the PAC meeting. They will be allowed to submit written comments that will then be passed on to the PAC with a copy provided to you. If you fail to identify a previously approved proposal with similar physics goals, the spokesperson for the previously approved proposal may request that final approval of your proposal be contingent on review by a subsequent PAC of the issues they want raised. If laboratory management agrees that the request has merit, the final approval of your proposal will be deferred until the following PAC has reviewed the situation.

Experiment Summaries

A summary of all approved and conditionally approved experiments can be found on line at: PAC reports can be found on line at:

Beam Time

The beam time request should be provided in some detail using the standard forms identified below. Do not request any contingency time as the scheduling process includes this time. The beam requirements and time request should include all of the time for the following activities: setup & installation; alignment; calibration; check out and testing without beam; commissioning with beam; physics measurements (list all currents, energies, targets target and experimental apparatus configuration changes, and [for Halls A and C] spectrometer angle changes); and decommissioning.


Letters-of-intent may be submitted to solicit the evaluation by the PAC of a new line of research before investing the large effort required to prepare a full proposal. Letters-of-intent will be made public after receiving PAC appraisal in the same manner as full proposals. For PAC32, contrary to tradition, we will allow serious letters of intent that identify physics that the PAC strongly encourages to "stake out" territory for the science program for two 12 GeV PAC cycles. With PAC recommendation for strong encouragement, we will treat such letters of intent in a manner similar to how we have traditionally treated deferred proposals submitted to the PAC (to remind you, deferred proposals must be resubmitted as a revised proposal to a future PAC. The revised proposal must address the issues and concerns raised by the PAC. A deferred proposal has established a claim to a physics measurement, but must be updated within one year - usually two PAC cycles - or it will lose this claim. For 12 GeV Letters of Intent we will use the "two PAC cycle" period, which will, for now, be two years.)

Due Date: New Proposals and Letters-of-Intent

Proposals, Updates, and Letters-of-Intent for PAC32 are due at the JLab User Liaison Office by close of business Wednesday, June 20, 2007.

Jefferson Lab
User Liaison Office, MS 12H
12000 Jefferson Avenue
Newport News, Virginia 23606


All submissions can be mailed or submitted electronically, electronic submissions are preferred. An electronic version must accompany all hard copies. Fax submissions are not acceptable.

All proposals and updates to be considered by PAC 32 must also include a completed:

Cover Sheet
Beam Time and Requirements List

These forms are available at the url:

The Lab Resources Requirements List, Hazard Identification Checklist, and Computing Requirements List normally included in PAC submissions are not required for the 12 GeV PAC.


For all proposals copies will be made in B&W. If color copies are preferred, provide 32 copies with your original.

Reference Material Hard Copies

If you would like any of the materials on the Web sent to you, please contact User Liaison via phone (757-269-6388), fax (757-269-6134) or e-mail (