General Meson SF Meeting Summary 9/30/21

PARTICIPANTS: Richard, Garth, Tanja, Stephen, Rolf, Patrick

MESON SF (Richard)

• working on 5 on 41 ZDC distributions - appears to be a problem with the simulation processing

• Technical note for diffractive reactions - updating uncertainties with Patrick

• for IP8: still work on going on component implementation - B0

• B0 needed for proton, e.g., ppi channel and pi0n
• have optics for B0 - full magnet will not be available in next few months
• does simulation have B0 optical properties implemented?

• ZDC placement - similar to IP6 driven by need to capture 6mrad cone

• aperture given by limit of each IP (4.5mrad for IP6 and ~6mrad for IP8)
• due to mechanical interference moves a little closer for IP8

• Decay length kaon important for Lambda - need geometric acceptances

• compare geometric detection fractions for two IPs

• optics different by IR
• t-resolution would change

• Differences - need to look for planes in the different detection planes

• Action items:

• check on B0 implementation, aim to get the ZDC distribution -> get t-dependence
• geometric acceptance - might get from G4e - check with Yulia on status of virtual planes for IP8 and possibility to get geometric acceptances for kaon

PION FORM FACTOR (Stephen, Garth)

• Plots for

• W-Q2: very different from fixed target
• detection efficiencies with cuts applied to reduce inclusive background: ~80%
• detection efficiency Q2 vs. -t: shows where hit edges of the ZDC

• Pion FF updated plot

• Next: IP8

KAON FORM FACTOR

• Ali studied the exclusive K-L channel

• no lambda decay

• Action items:

• include lambda decay

PDFS WITH LATTICE PLUS GLOBAL FITTING (Patrick)

• studies of systematic uncertainties when fitting data

• finite volume not important compared to lattice spacing and power correction - remove from fit

• Noticeable impact of including lattice uncertainties on uncertainties of valence quark distribution

• Impact of current-current data

• reduce uncertainties by 50% and 10% - same impact - indicates that experimental data is the bottleneck

NEXT MEETING: THURSDAY 14 OCTOBER AT 5PM ET