We report results from an experiment measuring the semi-inclusive reaction $d(e,e\'p_s)$
where the proton $p_s$ is moving at a large angle relative to the momentum transfer.
If we assume that the proton was a spectator to the reaction taking place on the
neutron in deuterium, the initial state of that neutron can be inferred. This method,
known as spectator tagging, can be used to study electron scattering from high-momentum
(off-shell) neutrons in deuterium. The data were taken with a 5.765 GeV electron
beam on a deuterium target in Jefferson Laboratory\'s Hall B, using the CLAS detector.
A reduced cross section was extracted for different values of final-state missing
mass $W^{*}$, backward proton momentum $\\vec{p}_{s}$ and momentum
transfer $Q^{2}$. The data are compared to a simple PWIA spectator model.
A strong enhancement in the data observed at transverse kinematics is not
reproduced by the PWIA model. This enhancement can likely be associated with
the contribution of final state interactions (FSI) that were not incorporated into
the model. A ``bound neutron structure function\'\' $F_{2n}^{eff}$ was extracted
as a function of $W^{*}$ and the scaling variable $x^{*}$ at extreme backward
kinematics, where effects of FSI appear to be smaller. For $p_{s}>400$ MeV/c,
where the neutron is far off-shell, the model overestimates the value of $F_{2n}^{eff}$ in
the region of $x^{*}$ between 0.25 and 0.6. A modification of the bound neutron
structure function is one of possible effects that can cause the observed deviation. |
