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Scatterings of galactic dark matter (DM) particles with the
constituents of celestial bodies could result in their accumulation
within these objects. Nevertheless, the finite temperature of the
medium sets a minimum mass, the evaporation mass, that DM particles
must have in order to remain trapped. DM particles below this mass are
very likely to scatter to speeds higher than the escape velocity, so
they would be kicked out of the capturing object and escape. In this
talk, I will discuss the DM evaporation mass for all spherical
celestial bodies in hydrostatic equilibrium, spanning the mass range
[10^{-10} - 10^2] solar masses. Here, I will illustrate the critical
importance of the exponential tail of the evaporation rate, which has
not always been appreciated in recent literature, and obtain a robust
result: for the geometric value of the scattering cross section and
for interactions with nucleons, the DM evaporation mass for all
spherical celestial bodies in hydrostatic equilibrium is approximately
given by $E_c/T_\chi \sim 30$ , where $E_c$ is the escape energy of DM
particles at the core of the object and $T_\chi$ is the DM
temperature. The minimum value of the DM evaporation mass is obtained
for super-Jupiters and brown dwarfs,$ m_{\rm evap} \simeq $ 0.7 GeV.
This result shows the minimum DM mass that could be theoretically
testable in any spherical celestial body.
The conclusions inferred are most relevant in the context of upcoming
experiments such as the James Webb infra-red telescope (JWST).
Based on: https://arxiv.org/abs/2104.12757