# Supernovae as Laboratories for sub-GeV Millicharged Particles

- Institution: CERN
- Speaker: Mariachiara Ingicco
- Year: 2026
- Language: English
- Source: [CERN](https://videos.cern.ch/record/3020976)
- Licence: [CERN](https://copyright.web.cern)
- Who can watch: Teens profiles and older (sources give no ratings; placed by Invisible Network from the source's own words)

We study the transport of self-interacting millicharged particles (MCPs) coupled to a massless dark photon in core-collapse supernovae (SNe), focusing on masses above the MeV scale. In this regime, strong self-couplings drive the formation of a relativistic fluid rather than a free-streaming gas. We extend the hydrodynamic framework developed for light MCPs to heavier masses, revisiting production, thermalization, and transport. Neglecting self-interactions at higher masses can lead to a qualitatively incomplete description of energy deposition and particle outflows. The interplay between self-interactions and trapping modifies the boundary between free-streaming and hydrodynamic regimes, indicating that standard SN cooling arguments may require revision. This framework provides a basis to account for fluid effects when assessing supernova constraints across sub-GeV and multi-MeV dark sectors.

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## Lectures

1. [Supernovae as Laboratories for sub-GeV Millicharged Particles](https://invisiblenetwork.ai/learn/cern/3020976/279dd5625a96), 10 min (CERN's player)