论文标题
密集中微子气体中的碰撞风味不稳定性
Collisional flavor instability in dense neutrino gases
论文作者
论文摘要
带电的电流中微子过程，例如$ν_e + n \ rightleftharpoons p + e^ - $和$ \ \barν_e + p \ rightleftharpoons n + e^ + $破坏了单个中微子的弱交互状态之间的风味相干性，从而削弱了其风味的振荡。但是，在密集的二进制合并中形成的核心折叠超新星或黑洞积聚磁盘中，这些“碰撞”过程可能会触发与强中性中微子 - 中性氨基尼利诺利缩减的合作。我们表明，在均质和各向同性中微子气体中存在两种类型的碰撞风味不稳定性，它们通过其真实频率对中微子密度$n_ν$的依赖而识别。不稳定性从一种类型到另一种类型，并在中微子气体的净电子Lepton数量可忽略不计的区域表现出类似共振的行为。在过渡区域，风味不稳定性以$ \ propton_ν^{1/2} $的速率增长。我们发现，黑洞积聚磁盘中的中微子气体易于碰撞引起的风味转化，中微子密度最高。结果，可以通过风味转化产生大量的重腿风味中微子，这可能会在随后的残留物进化中产生重要的后果。
Charged-current neutrino processes such as $ν_e + n \rightleftharpoons p + e^-$ and $\barν_e + p \rightleftharpoons n + e^+$ destroy the flavor coherence among the weak-interaction states of a single neutrino and thus damp its flavor oscillation. In a dense neutrino gas such as that inside a core-collapse supernova or the black hole accretion disk formed in a compact binary merger, however, these "collision" processes can trigger large flavor conversion in cooperation with the strong neutrino-neutrino refraction. We show that there exist two types of collisional flavor instability in a homogeneous and isotropic neutrino gas which are identified by the dependence of their real frequencies on the neutrino density $n_ν$. The instability transitions from one type to the other and exhibits a resonance-like behavior in the region where the net electron lepton number of the neutrino gas is negligible. In the transition region, the flavor instability grows exponentially at a rate $\propto n_ν^{1/2}$. We find that the neutrino gas in the black hole accretion disk is susceptible to the collision-induced flavor conversion where the neutrino densities are the highest. As a result, large amounts of heavy-lepton flavor neutrinos may be produced through flavor conversion, which can potentially have important ramifications in the subsequent evolution of the remnant.
