( A New Letter - Of - Intent to Jefferson Lab PAC - 29 ) First Measurement of Polarized EMC Effect for the Neutron December 5 , 2005

We propose to measure the EMC effect in polarized structure function for the neutron at using a polarized He and a polarized Xe targets in Hall A. Results of this measurement would provide the first data on polarized EMC effect and important information for our understanding of the medium modification of nucleon spin structure. In this document, we first review the history and theories of the unpolarized EMC effect, and present existing calculations on the polarized EMC effect. Experimental design of the proposed measurement is presented in section 2 and a possible design for the new polarized Xe target is described in section 3. Extractions of from He and Xe data are discussed in section 4. An analysis of all systematic and theoretical uncertainties is given in section 5. In section 6 we give the kinematics optimization and estimation of rates and statistical uncertainties for a polarized EMC measurement. We will then discuss possible physics impact and summarize the beam time request. Although we propose to use Xe, we will show that Ne is another possible nuclear target to use, which although requires more R&D effort, may provide similar or better statistical precision.