Search for strongly interacting dark matter at Belle II. (arXiv:2312.08970v1 [hep-ph])

Search for strongly interacting dark matter at Belle II. (arXiv:2312.08970v1 [hep-ph])
<a href="http://arxiv.org/find/hep-ph/1/au:+Liang_J/0/1/0/all/0/1">Jinhan Liang</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Liu_Z/0/1/0/all/0/1">Zuowei Liu</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Yang_L/0/1/0/all/0/1">Lan Yang</a>

A small component of dark matter (DM) that is strongly interacting with the
standard model sector is consistent with various experimental observations.
Despite the small abundance, strongly-interacting DM can lead to pronounced
signals in DM direct detection experiments. We study Belle II sensitivity on
strongly-interacting DM that has a MeV-GeV mass and couples with electrons. By
taking into account the substantial interactions between DM and electrons
within detectors, we compute the ceiling of the mono-photon signature at Belle
II, beyond which the mono-photon channel loses its sensitivity, and visible ECL
clusters due to DM scatterings assume significance. We study two ECL signatures
for strongly-interacting DM: the mono-cluster and the di-cluster channels. To
carry out detailed calculations and to compare with other constraints, we
consider DM models with light mediators, as they naturally lead to sizable
interaction cross sections. We compute exclusion regions for the di-cluster,
mono-cluster, and mono-photon channels. We find that Belle II (with currently
accumulated data of 362 fb$^{-1}$) can rule out a significant portion of the
parameter space above the ceilings of the constraints from various DM direct
detection and neutrino experiments, for the vector mediator case with mass
$gtrsim$10 MeV. Belle II also offers superior constraints on new light
particles compared to PBH for the scalar mediator with mass $gtrsim$10 MeV.

http://arxiv.org/icons/sfx.gif