Effects of energy-dependent scatterings on fast neutrino flavor conversions
Effects of energy-dependent scatterings on fast neutrino flavor conversions
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DOI：
10.1103/physrevd.106.123013
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发表时间：
2022-07
影响因子：
5
通讯作者：
Chinami Kato;H. Nagakura
中科院分区：
文献类型：
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作者：
Chinami Kato;H. Nagakura
稠密中微子气体中的中微子自相互作用可以引起集体的中微子味转换。快中微子味转换(FFC)是一种集体的中微子转换模式，它潜在地改变了核坍缩超新星和双星中子星合并的动力学和观测值。在没有中微子-物质相互作用(或碰撞)的情况下，FFC基本上是能量无关的，因此在以前的研究中一直使用单一能量处理。然而，中微子与物质的碰撞通常取决于中微子的能量，这表明在发生碰撞的FFC中可能会出现能量依赖的特征。在本文中，我们用等能散射(模拟核子散射)对多能量处理下的FFC进行了动力学模拟。我们发现，内、外散射的抵消发生在高能区，有效地减少了碰撞次数，进而影响了FFC的动力学。事实上，与单能源情况相比，FFC的寿命延长了，导致了大量的风味转化。我们的结果表明，多能量处理对于测量FFC对碰撞的敏感性是强制性的。我们还提供了一个有用的量来衡量碰撞的多能量效应对FFC的重要性。
Neutrino self-interactions in a dense neutrino gas can induce collective neutrino flavor conversions. Fast neutrino flavor conversions (FFCs), one of the collective neutrino conversion modes, potentially change the dynamics and observables in core-collapse supernovae and binary neutron star mergers. In cases without neutrino-matter interactions (or collisions), FFCs are essentially energy-independent, and therefore the single energy treatment has been used in previous studies. However, neutrino-matter collisions in general depend on neutrino energy, suggesting that energy-dependent features may emerge in FFCs with collisions. In this paper, we perform dynamical simulations of FFCs with iso-energetic scatterings (emulating nucleon scatterings) under multi-energy treatment. We find that cancellation between in- and out-scatterings happens in high energy region, which effectively reduces the number of collisions and then affects the FFC dynamics. In fact, the lifetime of FFCs is extended compared to the single-energy case, leading to large flavor conversions. Our result suggests that the multi-energy treatment is mandatory to gauge the sensitivity of FFCs to collisions. We also provide a useful quantity to measure the importance of multi-energy effects of collisions on FFCs.