Month: June 2021

New paper published on future positron-proton polarization transfer experiment

The European Physical Journal A has now published a paper led by Professor Puckett together with Professors Axel Schmidt of George Washington University and Jan Bernauer of Stony Brook University describing a future experiment to measure polarization transfer in positron-proton elastic scattering at large momentum transfers. These measurements would provide new information to constrain the effects of multi-photon-exchange in elastic lepton-proton scattering, thought to explain the discrepancy between cross section and polarization measurements in extractions of the proton electromagnetic form factor ratio at large momentum transfers.

FF ratio vs Q2
Future positron-proton polarization data (green “x”-es) compared to existing cross section and polarization data as a function of the momentum transfer Q^2
Form factor ratio vs. epsilon
Proton form factor ratio at Q^2 = 2.5 GeV^2 versus the virtual photon polarization epsilon, comparing projected future positron-proton measurements (blue triangles and red square) to existing electron-proton scattering data.