Energy Transfer by Feebly Interacting Particles in Supernovae: The Trapping Regime

Area of Science:

• Particle Physics
• Astrophysics
• Cosmology

Background:

• Feebly interacting particles (e.g., sterile neutrinos, dark photons, axions) are produced in proto-neutron stars (PNS) during core-collapse supernovae (CCSNe).
• These particles can decay, depositing energy outside the PNS, which constrains new particle physics models through supernova luminosity observations.

Purpose of the Study:

• To investigate the impact of particle production outside the PNS at large couplings.
• To analyze the energy transfer mechanisms for axions coupling to two photons.

Main Methods:

• Theoretical analysis of particle production and energy transfer mechanisms.
• Focus on axions as a prototypical case for large coupling scenarios.

Main Results:

• At sufficiently large couplings, particle production outside the PNS is significant.
• Energy transfer from the PNS becomes diffusive rather than ballistic for axions at large couplings, reducing deposited energy.
• This diffusive transfer substantially alters the constraints derived from supernova observations.

Conclusions:

• The standard assumption of ballistic energy transfer may not hold for feebly interacting particles at large couplings.
• New considerations for particle production outside the PNS are necessary for accurate model constraints.
• Findings impact the parameter space for particles probed in beam dump experiments and sub-GeV dark matter models.