12 GeV Parity-Violation Program

1. 12 GeV Parity-Violation Program Introductory Welcome Kees de Jager

2. PV Integral Part of 12 GeV Science • Office of Nuclear Physics Science Review (April 6-8, 2005) The 12 GeV Upgrade also provides a unique opportunity to use the electroweak interaction to search for physics beyond the Standard Model by performing low energy precision parity-violating measurements that are complementary to and comparable in sensitivity to searches at the Large Hadron Collider (LHC). The high intensity polarized electron beams available with the 12 GeV upgrade make possible a set of measurements that cannot be done anywhere else in the world until the construction of the International Linear Collider (ILC). This program would be sensitive to new particles at the TeV scale and probe channels not accessible with the LHC. These measurements would also provide a truly complementary technique to that above for the study of the quark structure of the nucleon. The reviewers consider this program challenging but an essential part of the overall future TJNAF science program. This program requires the proposed hall C upgrade for its initial phase and two additional large acceptance spectrometers for its longer term goals which are outside the scope of the Upgrade project. The reviewers consider the proposed phased approach of this program reasonable and the technical challenges justified.

3. PV Integral Part of 12 GeV Science • DNP Town Meeting on Hadronic Physics (January 12-14,2007) We are gratified that the 12 GeV Upgrade of CEBAF, a formal recommendation of the last Long Range Plan, is now well underway, with CD-2 expected this year. The associated science program has three major elements: the fundamental structure of hadrons, the physics of nuclei, and fundamental symmetry tests in nuclear physics. The planned research program in each of these areas has strengthened and solidified since the last Long Range Plan, underscoring the importance of constructing the Upgrade as quickly as possible. Hence, we recommend: • Recommendation 1: Our highest priority is the timely completion of the 12 GeV Upgrade of CEBAF and the start of its exciting research program. • Science and Equipment CDR for the NSAC LRP Resolution Meeting (April 12, 2007) • Tests of the Standard Model of electro-weak interactions and the determination of fundamental parameters of this model. Precision, parity-violating electron scattering experiments made feasible by the 12 GeV Upgrade have the sensitivity to search for deviations from the Standard Model that could signal the presence of new physics.

4. PV Integral Part of 12 GeV Science • NSAC Long Range Plan (December 2007) • Chapter In Search of the New Standard Model Two classes of PV experiments that will require investments in new experimental capabilities are envisioned for the 12 GeV CEBAF Upgrade. First, a next-generation Møller asymmetry experiment will exploit the high luminosity of the CEBAF electron beam, the doubling of the energy, and the experience gained in previous efforts, to determine the running of sin2θW with a precision comparable to that achieved with Z0-pole experiments. At present, the values of sin2θW obtained from Z-pole measurements at LEP and SLD are in poor agreement, giving significantly different predictions for the mass of the yet unseen Higgs boson. The PV Møller experiment at 12 GeV could help resolve this tension. A second thrust involves precise measurements of the PV deep-inelastic electron-deuteron and electron-proton asymmetry. These asymmetries are ~100 times larger than the PV Møller asymmetry, making a kinematic survey feasible. The variation of the asymmetry with both energy and Q2 – as well as the use of different targets – will probe a variety of largely unexplored aspects of the nucleon’s quark and gluon substructure. Ongoing theoretical activities will provide a comprehensive framework for interpretation of the deep-inelastic asymmetries and delineate their implications for both the SM and its possible extensions.

5. PV Integral Part of 12 GeV Science • The DOE Office of Science has accepted the Parity-Violating program as an integral (and highly promising) part of the 12 GeV Science Program. • The new Director of JLab, Hugh Montgomery, has expressed similar support in an email to Krishna Kumar: Nevertheless, I must confess that I am very interested in the development of the 12 GeV experimental program. Both Larry and Tony Thomas are aware of this interest, which I believe they share. In fact when your e-mail arrived this morning, I had to ask myself whether I had already sent you the e-mail which was high on my to-do list, to inquire after the status of the Moeller initiative. I will be interested to hear also about the Deep Inelastic experiment. You indicate that you anticipate $15M price tags on each. In that situation, it is clearly important to understand that estimate well, as a basis for any requests we may make. Such understanding will also be important when investigating international participation.…

6. DOE CRITICAL DECISION SCHEDULE • 2004-2005 Conceptual Design (CDR) - finished • 2004-2008 Research and Development (R&D) - ongoing • 2006 Advanced Conceptual Design (ACD) - finished • 2006-2008 Project Engineering & Design (PED) - ongoing • 2009-2014 Construction – starts in ~3 months! • Accelerator shutdown starts ~May 2012 • Accelerator commissioning ~May 2013 • 2013-2015 Pre-Ops (beam commissioning) • Hall commissioning starts October 2013 (in Hall A) (A) = Actual Approval Date

7. 12 GeV UPGRADE SCHEDULE

8. Format Choice of Submission to PAC34 • LOI has no formal status with JLab PAC, no intellectual authorship • Proposals are presented publicly to PAC, LOIs not (although Larry has indicated that he is willing to investigate this for such large LOIs with Mont and the PAC chair) • Many (most?) 12 GeV proposals so far have not been as detailed as one would expect/require from proposals • I strongly suggest that you dedicate some time at this meeting to making a choice between these options • Whatever you decide, Larry urges you to request, either in your submission letter or in the submitted document, that the PAC advises JLab management to convene a technical review before the following PAC (#35, that will take place either in January or July of 2010)