论文标题
高温电动对称性对新费米子的不恢复及其对男性生成的影响
High-Temperature Electroweak Symmetry Non-Restoration from New Fermions and Implications for Baryogenesis
论文作者
论文摘要
与当今的值相比,Electroweak对称性破裂的强度可能在早期宇宙中有很大差异。在标准模型中,Higgs真空期望值(VEV)消失,而Electroweak对称性在高于$ \ sim 160 $ GEV的温度下恢复,因为Higgs田间与高温等离子体的相互作用。但是,发现新的轻单元标量字段可能会改变这种行为。关键特征是对新颗粒质量的Higgs VEV的非标准依赖性,该质量可以在大型希格斯VEV上消失,从而引起对Higgs热质量的负校正,从而导致高温在高温下进行电子对称性。我们表明,这种效果也可以由新的单线费米子(New Singlet Fermions)引起,另一方面,这些效果的优势是不在树层的标量潜力上产生不稳定的方向,而不会带来其他严重的层次结构问题。随着温度下降,这种高温破裂阶段可能会连续演变为零温度的断裂阶段,也可以通过恢复对称性的临时阶段将两个阶段分开。我们讨论我们的构建如何自然地在新物理学的动机模型中出现,例如复合希格斯。这与男性生成特别相关,因为它打开了一类可能性,其中可以在高温相跃迁期间产生重子不对称性,而后来又不会被SPHALERS擦除。
The strength of electroweak symmetry breaking may substantially differ in the early Universe compared to the present day value. In the Standard Model, the Higgs vacuum expectation value (vev) vanishes and electroweak symmetry gets restored at temperatures above $\sim 160$ GeV due to the Higgs field interactions with the high-temperature plasma. It was however shown that new light singlet scalar fields may change this behaviour. The key feature is the non-standard dependence on the Higgs vev of the new particles mass which can vanish at large Higgs vev, inducing a negative correction to the Higgs thermal mass, leading to electroweak symmetry non-restoration at high temperature. We show that such an effect can also be induced by new singlet fermions which on the other hand have the advantage of not producing unstable directions in the scalar potential at tree level, nor bringing additional severe hierarchy problems. As temperature drops, such a high-temperature breaking phase may continuously evolve into the zero-temperature breaking phase or the two phases can be separated by a temporary phase of restored symmetry. We discuss how our construction can naturally arise in motivated models of new physics, such as Composite Higgs. This is particularly relevant for baryogenesis, as it opens a whole class of possibilities in which the baryon asymmetry can be produced during a high temperature phase transition, while not being erased later by sphalerons.