arXiv 1803.046932018-03-13hep-phastro-ph.HE

中微子的刘维尔项：味结构和波的解释

Liouville term for neutrinos: Flavor structure and wave interpretation

Tobias Stirner, Günter Sigl, Georg Raffelt

发表信息：: JCAP 05 (2018) 016
DOI：: 10.1088/1475-7516/2018/05/016

摘要：

用动力学方程$D\varrho=-i[{\sf H},\varrho]+{\cal C}[\varrho]$描述了天体物理环境中中微子的产生、吸收、输运和味道演化。它的基本元素是广义占有数$\varrho$，味空间中的矩阵，它依赖于时间$t$，空间$\bf x$和动量$\bf p$。换向器表达式根据振荡频率的矩阵$\sf H$对风味转换进行编码，而${\cal C}[\varrho]$表示源项和汇项以及碰撞。左侧的Liouville算子涉及$t$、$\bf x$和$\bf p$中的线性导数。超相对论中微子的简化表达式$D=\partial_t+\hat{\bf p}\cdot{\partial}_{\bf x}$最近受到了质疑，因为应该出现与味道相关的速度，而不是单位矢量$\hat{\bf p}$。此外，一个新的阻尼项被假定为结果。在这里，我们推导出完整的味道依赖的速度结构的刘维尔项，虽然它似乎只会导致高阶修正。在中微子振荡长度的尺度上，动力学方程可以看作是一阶波动方程。

英文摘要：

Neutrino production, absorption, transport, and flavor evolution in astrophysical environments is described by a kinetic equation $D\varrho=-i[{\sf H},\varrho]+{\cal C}[\varrho]$. Its basic elements are generalized occupation numbers $\varrho$, matrices in flavor space, that depend on time $t$, space $\bf x$, and momentum $\bf p$. The commutator expression encodes flavor conversion in terms of a matrix $\sf H$ of oscillation frequencies, whereas ${\cal C}[\varrho]$ represents source and sink terms as well as collisions. The Liouville operator on the left hand side involves linear derivatives in $t$, $\bf x$ and $\bf p$. The simplified expression $D=\partial_t+\hat{\bf p}\cdot{\partial}_{\bf x}$ for ultra-relativistic neutrinos was recently questioned in that flavor-dependent velocities should appear instead of the unit vector $\hat{\bf p}$. Moreover, a new damping term was postulated as a result. We here derive the full flavor-dependent velocity structure of the Liouville term although it appears to cause only higher-order corrections. Moreover, we argue that on the scale of the neutrino oscillation length, the kinetic equation can be seen as a first-order wave equation.

机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。

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