221 research outputs found
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
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