Super-Rosenbluth Measurements with Electrons and Positrons

Precise measurements of the proton form factor ratio mu*GE/GM from Rosenbluth separation measurements can be combined with Polarization based extractions to provide significant constraints on two-photon exchange contributions to the elastic e-p cross section. We present an overview of JLab experiment E05-017, the high-precision Super-Rosenbluth measurements of the proton form factor taken in Hall C of Jefferson Lab. We then examine what precision could be obtained for Super-Rosenbluth measurements using a low-intensity positron beam at Jefferson Lab.Comment: 6 pages, 4 figures. Conference proceedings from JPOS17 (https://www.jlab.org/conferences/JPos2017/

Coulomb distortion in high-Q^2 elastic e-p scattering

Recently, there has been a significant amount of activity to try and understand the discrepancy between Rosenbluth and polarization transfer measurements of the proton form factors. It has been suggested that the standard use of plane-wave Born approximation in extracting the form factors is insufficient, and that higher-order terms must also be included. Of the corrections missing in standard prescriptions, Coulomb distortion is the most well understood. In this paper, we examine the effect of Coulomb distortion on the extraction of the proton form factors.Comment: 3 pages, 5 figures, submitted to Phys. Rev.

Precise determination of low-Q nucleon electromagnetic form factors and their impact on parity-violating e-p elastic scattering

The extraction of the strangeness form factors from parity violating elastic electron-proton scattering is sensitive to the electromagnetic form factors at low Q^2. We provide parameterizations for the form factors and uncertainties, including the effects of two-photon exchange corrections to the extracted EM form factors. We study effect of the correlations between different form factors, in particular as they impact the parity violating asymmetry and the extraction of the strangeness form factors. We provide a prescription to extract the strangeness form factors from the asymmetry that provides an excellent approximation of the full two-photon correction. The corrected form factors are also appropriate as input for other low-Q analyses, although the effects of correlations and two-photon exchange corrections may be different.Comment: 9 pages, 4 figures, to be submitted to Phys. Rev.

Short-range correlations and their implications for isospin-dependent modification of nuclear quark distributions

The past decade has provided a much clearer picture of the structure of high-momentum components in nucleons, associated with hard, short-distance interactions between pairs of nucleons. Recent Jefferson Lab data on light nuclei suggest a connection between these so-called 'short-range correlations' and the modification of the quark structure of nucleons in the nuclear environment. In light of this discovery that the detailed nuclear structure is important in describing the nuclear quark distributions, we examine the potential impact of the isospin-dependent structure of nuclei to see at what level this might yield flavor-dependent effects in nuclear quark distributions.Comment: 10 pages, 2 figures, proceedings from the 21st international conference on few-body physic