Dark matter implications of the neutron anomaly

Motivated by the neutron decay anomaly, we reconsider the neutron decay model $n\to \chi \chi \chi$, where the new species $\chi$ plays the role of dark matter. We precisely compute the $\bar{\chi }n\to \chi \chi$ rate finding that fitting the anomaly compatibly with all bounds needs two ‘‘generations’’ of the $\chi$ particle.