[NT/RBRC seminar] Reframing azimuthal modulations in hard exclusive diffraction processes

by Dr Zhite Yu (Jefferson Laboratory)

Friday May 9, 2025, 11:00 AM → 1:00 PM US/Eastern

CFNS library (https://bnl.zoomgov.com/j/1614715193?pwd=WkwxODVWdzZzb29zQnZRVGp3VTBDQT09)

I will present a new formulation of azimuthal modulations in hard exclusive diffraction processes. These modulations are crucial for the phenomenological extraction and separation of various generalized parton distributions (GPDs). A key example is deeply virtual Compton scattering (DVCS), which will play an important role at the Electron-Ion Collider. Conventionally, GPDs are extracted from the angular modulations of DVCS in the Breit frame. However, the Bethe-Heitler (BH) subprocess interferes with DVCS, contaminating its azimuthal modulations and making it difficult to extract GPDs cleanly. We introduce a new formalism with an optimized choice of frame to describe azimuthal distributions. We demonstrate that this approach is more suitable for experimental analyses, as it allows for a consistent and uniform separation of contributions to the physical cross section from GPD-sensitive subprocesses (such as DVCS) and GPD-insensitive subprocesses (e.g., BH).