Update on E12-07-109 to PAC 47: Large Acceptance Proton Form Factor Ratio Measurements up to 14.5 GeV Using the Recoil-Polarization Method

During the last two decades a number of experiments have made precision measurements of the proton electromagnetic form factor ratio GEp/GMp in a wide range of momentum transfer Q using the polarization transfer method. The most important result of these experiments is the dramatic reduction of that ratio with Q between 1 ≤ Q ≤ 8.5 GeV. As a result, the field of nucleon electromagnetic form factors at large Q, connected to the worldwide effort to study Generalized Parton Distributions, has experienced a resurgence in interest and attention. The experiment under discussion, E12-07-109, was approved by PAC32. PAC35 allocated 45 days with a slightly reduced range of momentum transfer (12.5 GeV). E12-07-109 received a “High Impact Experiment” designation from PAC41. This document provides an update on the experiment preparation and a brief summary of the progress in the field of nucleon form factors since 2010.