High-energy neutrinos from dark matter particle self-capture within the Sun

Abstract

A potential flux of high-energy neutrinos from the annihilation of dark matter particles trapped within the Sun has been exploited to place indirect limits on particle dark matter. In most models, the dark matter interacts weakly, but the possibility of a dark matter particle with a large cross section for elastic scattering on other dark matter particles has been proposed in several contexts. I study the consequences of such dark matter self-interactions for the high-energy neutrino flux from annihilation within the Sun. The self-interaction among dark matter particles may allow dark matter in the halo to be captured within the Sun by scattering off of dark matter particles that have already been captured within the Sun. This effect is not negligible in acceptable and accessible regions of parameter space. Enhancements in the predicted high-energy neutrino flux from the Sun of tens to hundreds of percent can be realized in broad regions of parameter space. Enhancements as large as factors of several hundred may be realized in extreme regions of the viable parameter space. Large enhancements require the dark matter annihilation cross section to be relatively small, σAv < ∼ 10 −27 cm 3 s −1 . This phenomenology is interesting. First, self-capture is negligible for the Earth, so dark matter self-interactions break the correspondence between the solar and terrestrial neutrino signals. Likewise, the correspondence between indirect and direct detection limits on scattering cross sections on nuclei is broken by the self-interaction. These broken correspondences may evince strong dark matter self-interactions. In some cases, self-capture can lead to observable indirect signals in regions of parameter space where limits from direct detection experiments would indicate that no such signal should be observable. PACS numbers: 95.35.+d,95.30.Cq,95.55.Vj,98.35.Gi,98.80.Cq

Constraints on scalar asymmetric dark matter from black hole formation in neutron stars

“…Additionally, we ignore the self-capture effect. Dark matter may have a sizable self-interaction that leads to self-capture [42]. However, the self-capture saturates when the sum of the individual self-scattering cross sections becomes larger than the geometrical area over which the DM particles thermally distribute.…”

Realistic neutron star constraints on bosonic asymmetric dark matter

“…(20), (25), (31), and (39), respectively. The most constraining bounds arise from old neutron stars with low core temperatures, located in DM-dense regions.…”

“…C has been estimated in Ref. [25]. It becomes important only if C NS * 1, where NS is the neutron star lifetime.…”

Signatures of large composite Dark Matter states

“…That A X can be of order A s for this value means that there are possible DM models in which self-capture is significant (e.g. [43,44]). However, for large composite DM states, the fact that σ XX /m X ∝ m we see that for SM-like or heavier constituents, large composite states are well below elastic self-interaction bounds, so do not give interesting self-capture effects.…”