Constraints on light dark matter particles using white dwarf stars

Understand

We report constraints on the nucleon-dark matter particle cross section using the internal luminosity of observed white dwarf stars in the globular cluster Messier 4.

• Our results cover the parameter space corresponding to relatively light dark matter particles, in the mass range $0.1~GeV-5~GeV$, which is known to be very difficult to be probed by direct dark matter searches.
• The additional luminosity coming from self-annihilations of dark matter particles captured inside the stars must not exceed the observed luminosity.
• Imposing that condition, we obtain for the spin independent cross section of light dark matter particles on baryons $\sigma_{N\chi}$ the upper bound: $\sigma_{N\chi} < 4 \times 10^{-41}{\rm cm^2}$.