Are Recoil Polarization Measurements of $G_E^p/G_M^p$ Consistent With Rosenbluth Separation Data?

Abstract

Recent recoil polarization measurements in Hall A at Jefferson Lab show that the ratio of the electric to magnetic form factors for the proton decreases significantly with increasing Q^2. This contradicts previous Rosenbluth measurements which indicate approximate scaling of the form factors. The cross section measurements were reanalyzed to try and understand the source of this discrepancy. We find that the various Rosenbluth measurements are consistent with each other when normalization uncertainties are taken into account and that the discrepancy cannot simply be the result of errors in one or two data sets. If there is a problem in the Rosenbluth data, it must be a systematic, epsilon-dependent uncertainty affecting several experiments.