2023/12/11 by Pedro Dedin Neto, Neto, Pedro Dedin, Irene Tamborra +3 · 1 citation
Physics and Astronomy · Engineering · #Neutrino Physics Research #Astrophysics and Cosmic Phenomena #Particle accelerators and beam dynamics
paper · pdf · doi:10.48550/arxiv.2312.06556
In core-collapse supernovae and neutron star mergers, the neutrino density is so large that neutrino-neutrino refraction can lead to flavor conversion, if a zero-crossing is present in the neutrino flavor lepton number (FLN) angular distribution and the neutrino self-interaction strength μ=√(2) GF nν represents the characteristic timescale of the system. It has been empirically realized that the vacuum frequency ω=Δm2/2E affects the development of flavor conversion in the presence of zero-crossing even if ω≪ μ. Focusing on a homogeneous and axially symmetric neutrino gas, we explore the role of ω in the onset of flavor instabilities. We find that a non-zero vacuum frequency can be responsible for inducing flavor instabilities even when the neutrino self-interaction strength is much larger than the vacuum frequency. Moreover, mapping a neutrino ensemble with ω≠ 0 into an effective system with ω=0, we find that a system with no FLN zero-crossing can effectively develop one for ω≠ 0 becoming unstable.