Neutrino spectral split in the exact many-body formalism
Neutrino spectral split in the exact many-body formalism
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DOI：
10.1103/physrevd.98.083002
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发表时间：
2018-05
影响因子：
5
通讯作者：
S. Birol;Y. Pehlivan;A. Balantekin;T. Kajino
中科院分区：
文献类型：
--
作者：
S. Birol;Y. Pehlivan;A. Balantekin;T. Kajino
我们考虑了中微子通过中性电流弱力相互作用的多体系统。在这样一个系统中出现的多体效应可能在一些天体物理位置（如核心坍缩超新星）中发挥重要作用。在文献中，这种多体系统通常用平均场近似来处理，这是一种有效的基于忽略纠缠态的单体描述。本文考虑了单角度近似下两味混合有效情况下的原始多体系统，给出了一种不使用平均场近似的解。我们的解决方案是围绕一类特殊的多体本征态而制定的，当中微子从超新星辐射时，中微子自相互作用率降低时，这些多体本征态不会经历任何水平交叉。特别地，由正交的电子中微子和反中微子组成的初始态可以用这些特征态完全分解。假设这些条件是完全绝热的，因此这些特征态的演化遵循它们随相互作用速率的变化，我们表明，这个初始状态在平均场公式所预测的完全相同的能量下发生谱分裂。
We consider the many-body system of neutrinos interacting with each other through neutral current weak force. Emerging many-body effects in such a system could play important roles in some astrophysical sites such as the core collapse supernovae. In the literature this many-body system is usually treated within the mean field approximation which is an effective one-body description based on omitting entangled neutrino states. In this paper, we consider the original many-body system in an effective two flavor mixing scenario under the single angle approximation and present a solution without using the mean field approximation. Our solution is formulated around a special class of many-body eigenstates which do not undergo any level crossings as the neutrino self interaction rate decreases while the neutrinos radiate from the supernova. In particular, an initial state which consists of electron neutrinos and antineutrinos of an orthogonal flavor can be entirely decomposed in terms of those eigenstates. Assuming that the conditions are perfectly adiabatic so that the evolution of these eigenstates follow their variation with the interaction rate, we show that this initial state develops a spectral split at exactly the same energy predicted by the mean field formulation.