Time-reversal symmetry is broken for mixed and possibly unstable Dirac neutrino propagation through absorbing media. This implies that interplay between the neutrino mixing, refraction, absorption and/or decay can be described by non-Hermitian quantum dynamics. We derive an identity which sets up direct connection between the fundamental neutrino parameters (mixing angles, CP-violating phase, mass-squared splittings) in vacuum and their effective counterparts in matter.

中文翻译：

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由非厄米哈密顿量控制的三中微子振荡的重定相不变量

对于通过吸收介质的混合且可能不稳定的狄拉克中微子传播，时间反转对称性被打破。这意味着中微子混合、折射、吸收和/或衰变之间的相互作用可以通过非厄米量子动力学来描述。我们推导出一个恒等式，它在真空中的基本中微子参数（混合角、CP 违反相位、质量平方分裂）与其在物质中的有效对应物之间建立了直接联系。