Electron Scattering from a High-Momentum Neutron in Deuterium

Spokesperson

Sebastian Kuhn

Year

2002

Abstract

We report results from an experiment measuring the semiinclusive 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 and can be associated with the contribution of final state interactions (FSI) that were not incorporated into the model. A ``bound neutron structure function'' \f2neff was extracted as a function of $W^{*}$ and the scaling variable $x^{*}$ at extreme backward kinematics, where effects of FSI appear to be small. For $p_{s}>400\,\,\mathrm{MeV/c}$, where the neutron is far off-shell, the model overestimates the value of $F_{2n}$ 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.

Publication

1. A. V. Klimenko, S. E. Kuhn, and CLAS Collaboration Electron Scattering From High-Momentum Neutrons in Deuterium // Phys. Rev. C 73, 035212 (2006) arXiv:nucl-ex/0510032

Quantities

F₂ * P(P_t)   F₂ * P(P_s)   F₂(x^*,Q²)

Measurements