General MWG Meeting Summary 4/7/20

Participants: Arun Tadepalli, David Richars, Dmitry Romanov, Rolf Ent, Huey-Wen Lin, Julia Furletova, Tim Hobbs, Vladimir Berdnikov, Tanja Horn, Jorge Segovia, Tobias Frederico, Richard Trotta, (Craig Roberts)

Overview of the Workshop on Perceiving the Emergence through Hadron Mass through AMBER@CERN

• All presentations
• Round table summary

• Omits recent lQCD progress on ratio u_kaon/u_pion (Huey-Wen Lin)
• Omits progress on prediction of proton distribution functions, including dbar/ubar (Fei Gao)

• Additional material presented at the round table discussion

• discussion of QCD prediction for large-x behavior of pion PDF
• Sea-quark distribution in pion is completely unknown - Access available, possibly, via comparison between pi+ and pi- beams on isoscalar target.
• Glue distribution. Assuming NRQCD ideas are correct for charm quarks, then JAM glue PDF cannot be correct. Comparison parameter-free continuum predictions and JAM seems to suggest very different valence-quark, glue almost identical, very different sea distributions
• Meson PDAs and PDFs are related via light-front wave functions. Hence, expression of emergent hadronic mass (EHM) in one is also evident in the other. PDAs control hard exclusive processes. PDFs typically measured via inclusive processes. Appealing complementarity. Can one use diffractive scattering with two leading hadrons in the final state to access pion PDA?
• Spectroscopy prospects

Discussion of the Workshop on Pion and Kaon Structure Function at the EIC at CFNS (June 2-5)

• Topics of interest

• Resummation
• Meson PDA and PDF - light front wave function, so far only through the FF connection, what if have quasi-real meson target; LQCD: pion-pion operator and pion-vacuum operator
• Large x PDF - what are the real questions, scale dependence, process independence, what is expected, complications

• Overall format (remote meeting)

• Meet 4 hours per day: ET 8am - 1:00pm
• Short talks (25+5min)
• 4 days with 8 talks/day, plus 1 hour discussion each day
• Mix of experiment, phenomenology, and 10-15 experiment talks

• Action items:

• Draft an agenda and circulate for comments
• Check in with CFNS local organizer on plans
• Find out about remote meeting options, e.g. Zoom

Preparation for the EIC (remote) Pavia Workshop (May 22-24)

• Expect the Diffraction and Tagging Working group to reach out for contributions

• Main report from the Meson SF group likely on experimental equipment - how one can access meson structure and implication on experimental equipment. Next Working Meeting on this topic: Monday 13 April