Discussion 06-17-24

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Meeting Location

The 22 GeV Open Discussions will be held here:

• Date/Time: Monday, June 17 at 12:30 PM Jefferson Lab Local Time
• Physical Location: CEBAF Center F224/5
• Virtual Location: Zoom Meeting Number 161 111 8017 (The password is the two-digit number that appears before "GeV" in the first sentence of this section.

Agenda

• Introduction and Goals (Patrizia/Matt)
• Quark pressure and shear stress in the proton at 22 GeV ( Slides) (Volker Burkert)
• Pion and Kaon Form Factors with JLab at 22 GeV (Garth Huber) (deferred to a later date)

Comments and Questions

• To avoid confusion in presenting to a broader audience the role of our knowledge of gravity should be clarified in the measurement.
  • The objective is to measure the stress-energy tensor of the proton. The classical stress-energy tensor also appears in the Einstein field equations which relate this tensor to the curvature of space-time; however, our knowledge of gravity, i.e., the theory of General Relativity, is not relevant for making the measurement.
  • Unlike electromagnetic or weak probes, the particles being used to probe the proton in such experiments are not mediators of the gravitational force.
• What prediction is being tested by measuring the pressure as a function of radius? What behavior of QCD is being probed? What level of precision on the measurement of the pressure is required to draw conclusions about these tests?
• The final projected precision of pressure as a function of radius at 22 GeV includes uncertainties from both theory and experiment. What are the appropriate assumptions about the theoretical systematic uncertainties?
• Are both deeply virtual Compton scattering and threshold J/ψ production measuring the same properties of the proton? How are they complementary? Should the experimental results lead to the same conclusion?