A simple testable model of baryon number violation: Baryogenesis, dark matter, neutron–antineutron oscillation and collider signals

We study a simple TeV-scale model of baryon number violation which explains the observed proximity of the dark matter and baryon abundances. The model has constraints arising from both low and high-energy processes, and in particular, predicts a sizable rate for the neutron–antineutron ($n-\overline{n}$) oscillation at low energy and the monojet signal at the LHC. We find an interesting complementarity among the constraints arising from the observed baryon asymmetry, ratio of dark matter and baryon abundances, $n-\overline{n}$ oscillation lifetime and the LHC monojet signal. There are regions in the parameter space where the $n-\overline{n}$ oscillation lifetime is found to be more constraining than the LHC constraints, which illustrates the importance of the next-generation $n-\overline{n}$ oscillation experiments.