Enkeleida Katherine Lakuriqi, Temple University / Thomas Jefferson National Accelerator FacilityTitle: Measurement of the Neutron (3He) Spin Structure Function at Low Q2: A Connection Between the Bjorken and Drell-Hearn-Gerasimov Sum RulesAuthors: E.K. Lakuriqi, Z.-E. Meziani (Temple University); G. Cates (Princeton University)Abstract: The aim of E94-010 experiment is to determine the virtual photon-neutron asymmetry A1n(n,Q2) and the spin-dependent structure function g1n across the resonance and inelastic region by measuring the reaction 3He(e,e') over a wide range of four-momentum transfer Q2 and energy transfer n. Using the CEBAF longitudinally polarized electron beam combined with a high pressure polarized 3He target, we propose to measure the inclusive spin-dependent cross section with beam and target helicity parallel and antiparallel at four incident beam energies (E = 1.6GeV, 2.4GeV, 3.2GeV and 4.0GeV) and three scattering angles 15o, 25o, and 35o. We shall use the Hall A (Jefferson lab) spectrometers for electron detection. They will be used as two independent single arm spectrometers to double the solid angle and allow flexibility in the data taking at different angles. In the limit Q2 --> 0, the Bjorken sum rule is connected to the difference between the proton and neutron magnetic moments via the difference IPDHG - InDHG where IDHG is the Drell-Hearn-Gerasimov sum Rule. In this measurement we shall first study the Q2 evolution of the neutron extended DHG sum rule. Together with the measurement proposed in Hall B (PR-91-023) and that of SLAC (E-143; E = 9.7 GeV, q=45o), this experiment will allow the investigation of the Q2 evolution of the Bjorken sum rule IBj(Q2) from Q2 >= 2(GeV)2 down to Q2 >= 0.15(GeV)2 and therefore will help to clarify the structure of QCD rather than PQCD. All these measurements will be complementary to those of Hall B Experiment (E93-009). When combined with the proton measurement of Hall B and the SLAC E-143 measurement, the proposed CEBAF experiments will allow a first study of the low Q2 evolution of the Bjorken sum rule. |