Mechanism of the reaction 4He(e,e'd)2H.

Abstract

The cross section for the $^{4}\mathrm{He}$(e,e'd${)}^{2}$H reaction has been measured as a function of the four-momentum transfer q at a missing momentum of 125 MeV/c. The data show that this reaction cannot be described as quasielastic knockout of a deuteron. In a microscopic description of the (e,e'd) cross section, assuming a direct knockout mechanism, the q dependence reflects the p-n relative wave function in $^{4}\mathrm{He}$. However, even a calculation in this framework using a relativistic $^{4}\mathrm{He}$ wave function does not describe the data, indicating that other reaction mechanisms play a non-negligible role.