Positrons at JLab - Advancing Nuclear Science in Hall B

TL;DR

This paper discusses the potential of using polarized and unpolarized positron beams at JLab to enhance the understanding of proton structure and resolve discrepancies in form factor measurements, advancing nuclear physics research.

Contribution

It introduces new experimental approaches involving positron beams to improve measurements of GPDs, CFFs, and proton form factors, addressing longstanding scientific questions.

Findings

Positron beams can improve extraction of GPDs and CFFs in DVCS.

Unpolarized positrons can help resolve proton form factor discrepancies.

Using positrons offers new insights into two-photon exchange effects.

Abstract

In this talk I address two high impact physics programs that require the use of polarized and unpolarized positron beams in addition to using electron beams of the same energy. First, I address what will be gained from using positron beams in addition to electron beams in the extraction of the Compton Form Factors (CFFs) and generalized parton distributions (GPDs) from Deeply Virtual Compton Scattering (DVCS) on a proton target. As a second high impact science program I discuss an experimental scenario using unpolarized positrons to measure elastic scattering on protons in an effort to determine definitively the 2-photon exchange contributions in order to resolve a longstanding discrepancy in the determination of the proton's electric and magnetic form factors.