Off-diagonal dark-matter phenomenology: Exploring enhanced complementarity relations in nonminimal dark sectors

摘要

In most multicomponent dark-matter scenarios, two classes of processes generically contribute to eventrates at experiments capable of probing the nature of the dark sector. The first class consists of “diagonal”processes involving only a single species of dark-matter particle-processes analogous to those which arisein single-component dark-matter scenarios. By contrast, the second class consists of “off-diagonal”processes involving dark-matter particles of different species. Such processes include inelastic scattering atdirect-detection experiments, asymmetric production at colliders, dark-matter co-annihilation, and certainkinds of dark-matter decay. In typical multicomponent scenarios, the contributions from diagonal processesdominate over those from off-diagonal processes. Unfortunately, this tends to mask those features whichare most sensitive to the multicomponent nature of the dark sector. In this paper, by contrast, we point outthat there exist natural, multicomponent dark-sector scenarios in which the off-diagonal contributionsactually dominate over the diagonal. This then gives rise to a new, enhanced picture of dark-mattercomplementarity. In this paper, we introduce a scenario in which this situation arises and examine theenhanced picture of dark-matter complementarity which emerges.