Simple method of diagnosing fast flavor conversions of supernova neutrinos
Simple method of diagnosing fast flavor conversions of supernova neutrinos
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DOI：
10.1103/physrevd.98.103001
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发表时间：
2018-07
影响因子：
5
通讯作者：
B. Dasgupta;A. Mirizzi;M. Sen
中科院分区：
文献类型：
--
作者：
B. Dasgupta;A. Mirizzi;M. Sen
从超新星发出的中微子可能几乎立即在核心上方进行风味转换，这可能对超新星动力学和核合成产生影响。然而，这种快速转换的精确条件很难计算，并且需要了解与风味相关的中微子通量的完整角度分布，这在典型的超新星模拟中是无法获得的。在本文中，我们证明了整体风味演化在质量上类似于由背景物质和中微子密度决定的所谓“零模式”的增长，这可以仅使用电子轻子数分布的第二角矩，即${\ensuremath{\nu}}_{e}$和${\overline{\ensuremath{\nu}}}_{e}$通量的角分布的差异来可靠地预测。我们提出，这种零模式既不需要计算完整的格林函数，也不需要详细的角分布知识，可能有助于初步诊断具有适度解析角分布的超新星模拟中可能的快速风味转换。
Neutrinos emitted from a supernova may undergo flavor conversions almost immediately above the core, with possible consequences for supernova dynamics and nucleosynthesis. However, the precise conditions for such fast conversions can be difficult to compute and require knowledge of the full angular distribution of the flavor-dependent neutrino fluxes that is not available in typical supernova simulations. In this paper, we show that the overall flavor evolution is qualitatively similar to the growth of a so-called ``zero mode'' determined by the background matter and neutrino densities, which can be reliably predicted using only the second angular moments of the electron lepton number distribution, i.e., the difference in the angular distributions of the ${\ensuremath{\nu}}_{e}$ and ${\overline{\ensuremath{\nu}}}_{e}$ fluxes. We propose that this zero mode, which neither requires computing the full Green's function nor detailed knowledge of the angular distributions, may be useful for a preliminary diagnosis of possible fast flavor conversions in supernova simulations with modestly resolved angular distributions.