Linear analysis of fast-pairwise collective neutrino oscillations in core-collapse supernovae based on the results of Boltzmann simulations

Journal Article · 20 May 2019 · Physical Review. D.

DOI: https://doi.org/10.1103/physrevd.99.103011 · OSTI ID:1612910

Azari, Milad Delfan ^[1]; Yamada, Shoichi ^[1]; Morinaga, Taiki ^[1]; Iwakami, Wakana ^[2]; Okawa, Hirotada ^[3]; Nagakura, Hiroki ^[4]; Sumiyoshi, Kohsuke ^[5]

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1. Waseda Univ., Tokyo (Japan)
2. Waseda Univ., Tokyo (Japan); Kyoto Univ. (Japan)
3. Waseda Univ., Tokyo (Japan); Kyoto Univ. (Japan); Waseda Institute for Advanced Study, Tokyo (Japan)
4. Princeton Univ., NJ (United States)
5. Numazu College of Technology, Shizuoka (Japan)

Neutrinos are densely populated deep inside the core of massive stars after their gravitational collapse to produce supernova explosions and form compact stars such as neutron stars and black holes. It has been considered that they may change their flavor identities through so-called fast-pairwise conversions induced by mutual forward scatterings. If that is really the case, the dynamics of supernova explosion will be influenced, since the conversion may occur near the neutrino sphere, from which neutrinos are effectively emitted. In this paper, we conduct a pilot study of such possibilities based on the results of fully self-consistent, realistic simulations of a core-collapse supernova explosion in two spatial dimensions under axisymmetry. As we solved the Boltzmann equations for neutrino transfer in the simulation not as a postprocess but in real time, the angular distributions of neutrinos in momentum space for all points in the core at all times are available, a distinct feature of our simulations. We employ some of these distributions extracted at a few selected points and times from the numerical data and apply linear analysis to assess the possibility of the conversion. We focus on the vicinity of the neutrino sphere, where different species of neutrinos move in different directions and have different angular distributions as a result. This is a pilot study for a more thorough survey that will follow soon. Here, we find no positive sign of conversion unfortunately at least for the spatial points and times we studied in this particular model. We hence investigate rather in detail the condition for the conversion by modifying the neutrino distributions rather arbitrarily by hand.

• Research Organization: Univ. of California, Oakland, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC)
• Grant/Contract Number: SC0018297
• OSTI ID: 1612910
• Alternate ID(s): OSTI ID: 1546206
• Journal Information: Physical Review. D., Vol. 99, Issue 10; ISSN 2470-0010
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English