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\documentstyle[11pt,apsab]{article} \nofiles \MeetingID{DNP04} %\DateSubmitted{20040621} \SubmittingMemberSurname{Zheng} \SubmittingMemberGivenName{Xiaochao} %\SubmittingMemberID{60057843} \SubmittingMemberEmail{xiaochao@jlab.org} \SubmittingMemberAffil{Argonne National Lab} \PresentationType{oral} \SortCategory{13b.}{}{}{} \begin{document} \Title{Measurements of $G_E^p/G_M^p$ Using a Polarized Target} \AuthorSurname{Zheng} \AuthorGivenName{Xiaochao} \thanks{mailing address: 12000 Jefferson Avenue, Newport News, VA 23606} %\AuthorEmail{xiaochao@jlab.org} \AuthorAffil{Argonne National Lab} E \begin{abstract} The nucleon elastic form factors are important inputs to our understanding of the nucleon structure and hadronic physics. However, in the region $Q^2>2$~(GeV/c)$^2$ there is a large discrepancy between data on the proton $G_E^p/G_M^p$ ratio obtained using two different techniques - Rosenbluth separation and polarization transfer. Although recently it has been shown that the two-photon exchange (TPE) might be the solution, a full understanding of TPE has not been achieved. Whether it fully explains the discrepancy in the large $Q^2$ region and whether there are other mechanisms that may cause the discrepancy are still unknown. We present here a different approach aimed at understanding the $G_E^p/G_M^p$ data. We plan to measure the asymmetry of elastic ep scattering using a polarized beam and a polarized proton target, from which $G_E^p/G_M^p$ up to $Q^2=5.6$~(GeV/c)$^2$ will be extracted using the formalism of double polarization asymmetries. A proposal has been submitted to JLab PAC-26. The experimental setup and the expected uncertainties will be presented. This work is supported by the U.S. Department of Energy, Office of Nuclear Physics, under contract No. W-31-109-ENG-38. \end{abstract} \end{document}