Leptogenesis from heavy right-handed neutrinos in CPT violating backgrounds.
Leptogenesis from heavy right-handed neutrinos in CPT violating backgrounds.
复制标题
违反 CPT 背景中重右手中微子的轻子生成。
DOI：
10.1140/epjc/s10052-018-5587-5
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Bossingham T
中科院分区：
文献类型：
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作者：
Bossingham T
我们讨论leptogenesis模型中的重右手Majorana中微子传播恒定，但在其他通用CPT违反轴向类时背景（由弦理论的动机）。在远高于电弱相变温度的温度下，我们近似地但解析地（使用Padé近似）求解了相应的玻尔兹曼方程，该方程描述了从重中微子到标准模型轻子的树能级衰变产生轻子不对称性。在这样的温度下，这些轻子实际上是无质量的。目前的工作完成了一个严格的方式初步处理相同的系统，由一些本作者。在早期的工作中，轻子的不对称性是通过考虑静止的右手中微子的衰变而粗略估计的。我们目前的分析包括重中微子的热动量模式，这导致了总轻子不对称性，与以前的估计相比，它大了两倍。尽管如此，我们目前和初步的冻结结果是一致的（在不确定性范围内）。我们的分析依赖于一种新的使用Padé近似来解决玻尔兹曼方程，并可能在宇宙学中更广泛地使用。
We discuss leptogenesis in a model with heavy right-handed Majorana neutrinos propagating in a constant but otherwise generic CPT-violating axial time-like background (motivated by string theory). At temperatures much higher than the temperature of the electroweak phase transition, we solve approximately, but analytically (using Padé approximants), the corresponding Boltzmann equations, which describe the generation of lepton asymmetry from the tree-level decays of heavy neutrinos into Standard Model leptons. At such temperatures these leptons are effectively massless. The current work completes in a rigorous way a preliminary treatment of the same system, by some of the present authors. In this earlier work, lepton asymmetry was crudely estimated considering the decay of a right-handed neutrino at rest. Our present analysis includes thermal momentum modes for the heavy neutrino and this leads to a total lepton asymmetry which is bigger by a factor of two as compared to the previous estimate. Nevertheless, our current and preliminary results for the freezeout are found to be in agreement (within auncertainty). Our analysis depends on a novel use of Padé approximants to solve the Boltzmann equations and may be more widely useful in cosmology.