Summary 1/23/18

PARTONS AND TCS

• PARTONS is a C++ software framework dedicated to the phenomenology of Generalized Parton Distributions (GPDs). It provides a necessary bridge between models of GPDs and experimental data measured in various exclusive channels, like Deeply Virtual Compton Scattering (DVCS) and Deeply Virtual Meson Production (DVMP).

• Further details and instructions on using the framework can be found here

• For Timelike Compton Scattering (TCS): a code exists at NLO, but has yet to be implemented.

• Next steps:

• Dialogue between experiment and PARTONS regarding implementation of TCS. There is currently no projected timeframe, but it would benefit from experimental efforts
• Dialogue with experiment to develop support for experiment rate projections and impact of measurement on GPD extractions

TIMELIKE COMPTON SCATTERING EXPERIMENT

• Theoretical motivation includes access to the GPD E, in particular the imaginary part that allows for accessing orbital angular momentum

• New development since 2017 collaboration meeting is the addition of the Compact Photon Source - increased figure of merit

• Based on very preliminary studies, the experiment can make an impact on global GPD extractions and is competitive with other envisioned experiments with transverse target

• Next steps:

• Prepare a proposal to the PAC46 (2018)
• Need to make real rate projections
• Refine physics case
• Check impact of radiation due to e-/e+ production when beam interacts with a 1% radiator (target)
• Correlated with the previous point, check if the envisioned X-Y tracker will be operational in the projected radiation environment. During SANE operations, the tracker suffered from secondaries and was not functional as originally intended