论文标题
快速集体中微子风味振荡的纠缠和相关性
Entanglement and correlations in fast collective neutrino flavor oscillations
论文作者
论文摘要
集体中微子振荡在运输Lepton风味的天体物理环境中起着至关重要的作用，例如超新星和中子二元合并残留物，其特征是中微子密度较大。在这些设置中，均值场近似中的模拟表明，中微子 - 中微子的相互作用可以超过真空振荡，并在时间尺度上产生快速的集体风味演变，$ t \proptoμ^{ - 1} $，$μ$ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $。在这项工作中，我们研究了简单的多角度几何形状中的完整平衡风味动力学，在平均场线线性稳定性分析中显示快速振荡。为了关注简单的初始条件，我们分析了完整多体性动力学中的配对相关性和纠缠的产生，这是系统中中微子数量$ n $的函数，最多成千上万的中微子。与仅具有两个中微子光束的简单几何形状类似，我们确定了三个方案：稳定的配置，具有消失的风味振荡，略有不稳定的配置，并在长时间尺度上发生进化，$τ\ y \ youth \ libous^{ - 1} { - 1} \ sqrt {n} $，以及不稳定的配置，以及不稳定的配置， $τ\ log（1} \ log（n）$。我们提供的证据表明，这些快速集体模式是通过相同的动力学过渡产生的，该模式导致慢速双极振荡，建立了这两种现象之间的联系并解释了它们的时间尺度的差异。最后，我们讨论了半古典近似值，该近似在短到中期尺度上再现纠缠熵，并且在具有更复杂的几何形状的情况下，经典模拟方法开始变得低效。
Collective neutrino oscillations play a crucial role in transporting lepton flavor in astrophysical settings like supernovae and neutron star binary merger remnants, which are characterized by large neutrino densities. In these settings, simulations in the mean-field approximation show that neutrino-neutrino interactions can overtake vacuum oscillations and give rise to fast collective flavor evolution on time-scales $t\proptoμ^{-1}$, with $μ$ proportional to the local neutrino density. In this work, we study the full out-of-equilibrium flavor dynamics in simple multi-angle geometries displaying fast oscillations in the mean field linear stability analysis. Focusing on simple initial conditions, we analyze the production of pair correlations and entanglement in the complete many-body-dynamics as a function of the number $N$ of neutrinos in the system, for up to thousands of neutrinos. Similarly to simpler geometries with only two neutrino beams, we identify three regimes: stable configurations with vanishing flavor oscillations, marginally unstable configurations with evolution occurring on long time scales $τ\approxμ^{-1}\sqrt{N}$, and unstable configurations showing flavor evolution on short time scales $τ\approxμ^{-1}\log(N)$. We present evidence that these fast collective modes are generated by the same dynamical phase transition which leads to the slow bipolar oscillations, establishing a connection between these two phenomena and explaining the difference in their time scales. We conclude by discussing a semi-classical approximation which reproduces the entanglement entropy at short to medium time scales and can be potentially useful in situations with more complicated geometries where classical simulation methods starts to become inefficient.
