As part of the ongoing Jefferson Lab Strategic Plan development, we held a Town Meeting on March 16, 2012, for users to bring their ideas and discuss the following issues:
- Vision for the Future (5 - 20+ years)
- Lost or missed opportunities ?
- Required New Initiatives ?
Here is a short summary: Several talks addressed necessary equipment upgrades to maximize the Physics output from experiments with 12 GeV beam in all 4 Halls:
1) A PbWO4 forward calorimeter for Hall D to study rare eta decays (L. Gan) 2) Modifications to the Hall B photon tagger to operate with 11 GeV beams, with the goal (among others) to hunt for possible “hidden” neutral scalar bosons (A. Gasparian) 3) A transversely polarized H/D (ammonia or Lithium-hydride) DNP target for the rich program of TMDs and GPDs in Halls A and B (D. Crabb) 4) A facility for polarized positrons needed to study form factors and GPDs (E. Voutier) 5) A fast tracking trigger to increase the luminosity and reduce the data stream of large acceptance detectors like CLAS12 (M. Mestayer) 6) A set of RICH counters for CLAS12 to achieve full particle identification over the relevant range of momenta to accomplish the complete study of TMDs and tagged structure functions over a wide kinematic range (P. Rossi) 7) A combination of existing detectors for an optimized program of hypernucle-ar physics (L. Tang)
In addition, the talk by W. Melnitchouk pointed out the importance of measuring po-larized structure functions of the neutron at large x without nuclear binding uncer-tainties, perhaps using polarized tritium targets or some kind of spectator tagging.
Stan Brodsky covered a wide range of possibly Physics topics with 12 GeV that should be studied and pursued if feasible; in particular he emphasized charm pro-duction.
Pawel Nadel-Turonski presented the case for a medium-energy, high luminosity electron-ion collider, which is being pursued as the next logical major project for Jefferson Lab.
Two remaining talks made the case for substantially different future facilities at the lab: An electron-electron collider for precision tests of the standard model and pho-ton-photon fusion (C. Hyde) and a fixed-target, high energy program with 25-75 GeV beams (K. Hafidi).
See also http://wwwold.jlab.org/div_dept/physics_division/Physics_Town_Meeting.pdf for the previous town meeting held by the JLab Physics division in December 2011.