论文标题
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$ν$ Electroweak Baryogenesis: The Scalar Singlet Strikes Back
论文作者
论文摘要
我们对标准模型的一般单重标量延伸的参数空间进行了彻底的扫描，以识别可以根据电动eakeakbaryogeny机制所要求的强大一阶相变的区域。我们发现，考虑到气泡成核是对参数空间的基本限制，并为其提供了保守而快速的估计，以实现有效的参数空间扫描。事实证明，允许的区域已经通过HIGGS信号强度测量的标量混合的约束来显着探测。我们还考虑在标量和形成重型（伪） - 迪拉克对中添加具有Yukawa耦合的新的中微子单元字段，例如在线性或反向锯中中微子质量产生的机制中。有趣的是，我们确定了相变强度与电动真空的稳定性之间的相互作用，这使这些Yukawa耦合变得任意大。因此，它们的包容性不会改变早期的现象学或允许参数空间很大。相反，我们发现允许参数空间的区域，中微子单元的存在将显着修改对撞机的现象学，从而在Higgs和Singlet标量衰减中产生有趣的新特征。
We perform a thorough scan of the parameter space of a general singlet scalar extension of the Standard Model to identify the regions which can lead to a strong first-order phase transition, as required by the electroweak baryogenesis mechanism. We find that taking into account bubble nucleation is a fundamental constraint on the parameter space and present a conservative and fast estimate for it to enable efficient parameter space scanning. The allowed regions turn out to be already significantly probed by constraints on the scalar mixing from Higgs signal strength measurements. We also consider the addition of new neutrino singlet fields with Yukawa couplings to both scalars and forming heavy (pseudo)-Dirac pairs, as in the linear or inverse see-saw mechanisms for neutrino mass generation. Interestingly, we identify an interplay between the strength of the phase transition and the stability of the electroweak vacuum which prevents these Yukawa couplings to become arbitrarily large. Thus, their inclusion does not alter the early universe phenomenology or allowed parameter space in a significant way. Conversely, we find allowed regions of the parameter space where the presence of the neutrino singlets would remarkably modify the collider phenomenology, yielding interesting new signatures in Higgs and singlet scalar decays.
