标题： 电子中微子轻子数交叉：与超新星核心物理的变化 显示英文标题

标题： Electron-neutrino lepton number crossings: variations with the supernova core physics

摘要： 影响核心坍缩超新星（SNe）中快速中微子味转换的关键因素是电子中微子轻子数（ELN）的角度分布形状。ELN交叉的存在表明了有利的味转换条件。然而，ELN交叉与超新星（SN）特性之间的依赖关系仅部分被理解。我们研究了一套12个球对称中微子-流体动力学模拟，这些模拟针对质量为$18.6 M_\odot$的超新星核心坍缩；每个模型采用了不同的微观物理过程（即三种不同的核状态方程，包括和不包括μ子生成），并包含或不包含原中子星对流的混合长度处理。我们通过求解玻尔兹曼方程来计算中微子角度分布，基于我们模拟套件中每个超新星模拟在六个选定的反弹后时间点提取的静态流体特性。我们探讨了ELN分布与超新星微观物理和原中子星对流之间的依赖关系。我们发现后者将原中子星半径向外移动，有利于在更大的半径处出现ELN交叉。另一方面，μ子生成导致原中子星收缩，促进了在较小半径处出现ELN交叉。这些效应轻微地依赖于核状态方程。我们的发现突显了超新星微观物理、原中子星对流和中微子传输对ELN角度分布的微妙影响。 显示英文摘要

摘要： A crucial ingredient affecting fast neutrino flavor conversion in core-collapse supernovae (SNe) is the shape of the angular distribution of the electron-neutrino lepton number (ELN). The presence of an ELN crossing signals favorable conditions for flavor conversion. However, the dependence of ELN crossings on the SN properties is only partially understood. We investigate a suite of 12 spherically symmetric neutrino-hydrodynamics simulations of the core collapse of a SN with a mass of $18.6 M_\odot$; each model employs different microphysics (i.e., three different nuclear equations of state, with and without muon creation) and includes or not a mixing-length treatment for proto-neutron star convection. We solve the Boltzmann equations to compute the neutrino angular distributions relying on static fluid properties extracted from each of the SN simulations in our suite for six selected post-bounce times. We explore the dependence of the ELN distributions on the SN microphysics and proto-neutron star convection. We find that the latter shifts the proto-neutron star radius outwards, favoring the appearance of ELN crossings at larger radii. On the other hand, muon creation causes proto-neutron star contraction, facilitating the occurrence of ELN crossings at smaller radii. These effects mildly depend on the nuclear equation of state. Our findings highlight the subtle impact of the SN microphysics, proto-neutron star convection, and neutrino transport on the ELN angular distributions.