Baryon Asymmetry of the Universe from Lepton Flavor Violation
Baryon Asymmetry of the Universe from Lepton Flavor Violation
复制标题
轻子味破坏导致的宇宙重子不对称
DOI：
10.1103/physrevlett.129.011803
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发表时间：
2022
影响因子：
8.6
通讯作者：
Yamada Masaki
中科院分区：
文献类型：
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作者：
Mukaida Kyohei;Schmitz Kai;Yamada Masaki
电荷-轻子风味违和（CLFV）是超越标准模型的确凿证据。在即将进行的实验中发现的CLFV将表明，CLFV过程在早期宇宙中相对较低的温度下一定是有效的。在这封信中，我们指出，这种高效的CLFV相互作用开辟了创造宇宙重子不对称的新途径。首先，我们引用了从带电轻子汤川相互作用到标准模型等离子体中的化学输运的双环修正，这意味着非零轻子风味不对称加起来足以产生重子不对称。然后，我们描述了两种我们称之为“轻子风味形成”的情况，其中有效的CLFV过程负责产生原始轻子风味不对称，随后通过弱弹子过程转化为重子不对称。在这里，从轻子风味不对称到重子不对称的转换因子被电荷-轻子汤川耦合的平方所抑制，这为观测到的重子-光子比的小提供了一个自然的解释。
Charged-lepton flavor violation (CLFV) is a smoking-gun signature of physics beyond the standard model. The discovery of CLFV in upcoming experiments would indicate that CLFV processes must have been efficient in the early Universe at relatively low temperatures. In this Letter, we point out that such efficient CLFV interactions open up new ways of creating the baryon asymmetry of the Universe. First, we quote the two-loop corrections from charged-lepton Yukawa interactions to the chemical transport in the standard model plasma, which imply that nonzero lepton flavor asymmetries summing up toare enough to generate the baryon asymmetry. Then, we describe two scenarios of what we callleptoflavorgenesis, where efficient CLFV processes are responsible for the generation of primordial lepton flavor asymmetries that are subsequently converted to a baryon asymmetry by weak sphaleron processes. Here, the conversion factor from lepton flavor asymmetry to baryon asymmetry is suppressed by charged-lepton Yukawa couplings squared, which provides a natural explanation for the smallness of the observed baryon-to-photon ratio.