Self-Interacting Dark Sectors in Supernovae Can Behave as a Relativistic Fluid

Self-Interacting Dark Sectors in Supernovae Can Behave as a Relativistic Fluid
Damiano F. G. Fiorillo, Edoardo Vitagliano
arXiv:2404.07714v2 Announce Type: replace-cross
Abstract: We revisit supernova (SN) bounds on a hidden sector consisting of millicharged particles $chi$ and a massless dark photon. Unless the self-coupling is fine-tuned to be small, rather than exiting the SN core as a gas, the particles form a relativistic fluid and subsequent dark QED fireball, streaming out against the drag due to the interaction with matter. Novel bounds due to excessive energy deposition in the mantle of low-energy SNe can be obtained. The cooling bounds from SN 1987A are unexpectedly not affected in the free-streaming regime. The inclusion of $chibar{chi}rightarrow rm SM$ substantially modifies the constraints in the trapping regime, which can only be treated hydrodynamically. Our results can be adapted to generic sub-GeV self-interacting dark sectors.arXiv:2404.07714v2 Announce Type: replace-cross
Abstract: We revisit supernova (SN) bounds on a hidden sector consisting of millicharged particles $chi$ and a massless dark photon. Unless the self-coupling is fine-tuned to be small, rather than exiting the SN core as a gas, the particles form a relativistic fluid and subsequent dark QED fireball, streaming out against the drag due to the interaction with matter. Novel bounds due to excessive energy deposition in the mantle of low-energy SNe can be obtained. The cooling bounds from SN 1987A are unexpectedly not affected in the free-streaming regime. The inclusion of $chibar{chi}rightarrow rm SM$ substantially modifies the constraints in the trapping regime, which can only be treated hydrodynamically. Our results can be adapted to generic sub-GeV self-interacting dark sectors.