Electrodisintegration of Deuteron into Dark Matter and Proton Close to Threshold

We discuss an investigation of the dark matter decay modes of the neutron, proposed by Fornal and Grinstein (2018-2020), Berezhiani (2017, 2018) and Ivanov et al. (2018) for solution of the neutron lifetime anomaly problem, through the analysis of the electrodisintegration of the deuteron d into dark matter fermions ? and protons p close to threshold. We calculate the triple-differential cross section for the reaction e(-)+d & RARR;?+p(+)e(-) and propose to search for such a dark matter channel in coincidence experiments on the electrodisintegration of the deuteron e(-)+d & RARR;n+p+e(- )into neutrons n and protons close to threshold with outgoing electrons, protons, and neutrons in coincidence. An absence of neutron signals should testify to a detection of dark matter fermions.