论文标题
暗物质和MUON $ G-2 $异常通过比例对称破坏
Dark Matter and Muon $g-2$ Anomaly via Scale Symmetry Breaking
论文作者
论文摘要
没有希格斯质量项的标准模型（SM）是规模不变的。吉尔德纳（Gildener）和温伯格（Weinberg）通过在四分之一的形式中包括标量的乘法来概括规模不变标准模型（SISM）。他们指出，沿着平坦的方向只有一个标量（称为Scalon）在经典上是无质量的，所有其他标量都是巨大的。在这里，我们选择一个带有一个Scalon和一个重标量的SISM，并扩展了通过类似矢量的Lepton（VLL）进一步尊重规模的不变性。通过适当选择平坦的方向，重型标量享受$ \ mathbb {z} _2 $对称性，并被假定为DM粒子。 Scalon通过Higgs-portal连接可见的和暗区域，并通过与Muon Lepton和VLL相互作用。 vll在$ u（1）_y $下收取，并与$γ/z $玻色子互动。我们表明，该模型正确地说明了宇宙中观察到的暗物质（DM）遗物丰度，同时自然地避免了直接检测（DD）实验的当前和未来界限。此外，该模型能够解释在Fermilab中观察到的$（G-2）_μ$异常。我们还显示了SISM情景中的一个功能，该功能在其他Higgs-Portal模型中不存在；尽管拥有希格斯 - 门户$ | h |^2 s^2 $（$ s $是Scalon），但Electroweak Symmetry Breaking打破后的有效潜力缺乏一个重要的预期顶点$ H S^2 $。该属性立即禁止树级别的隐形希格斯衰减$ h \ to ss $和一环higgs衰减$ h \toμ^+μ^ - $。
The Standard Model (SM) without the Higgs mass term is scale invariant. Gildener and Weinberg generalized the scale invariant standard model (SISM) by including the multiplication of scalars in quartic forms. They pointed out that along the flat direction only one scalar -- called the scalon -- is classically massless and all other scalars are massive. Here we choose a SISM with one scalon and one heavy scalar and extend that further respecting the scale invariance by a vector-like lepton (VLL). By an appropriate choice of the flat direction, the heavy scalar enjoys the $\mathbb{Z}_2$ symmetry and is assumed as DM particle. The scalon connects the visible and dark sector via the Higgs-portal and by interacting with both the muon lepton and the VLL. The VLL is charged under $U(1)_Y$ and interacts with $γ/Z$ bosons. We show that the model correctly accounts for the observed dark matter (DM) relic abundance in the universe, while naturally evading the current and future bounds from direct detection (DD) experiments. Moreover, the model is capable to explain the $(g-2)_μ$ anomaly observed in Fermilab. We also show a feature in SISM scenarios which is not present in other Higgs-portal models; despite having the Higgs-portal term $|H|^2 s^2$ ($s$ being the scalon) in SISM, the effective potential after the electroweak symmetry breaking lacks an important expected vertex $h s^2$. This property immediately forbids the tree-level invisible Higgs decay $h\to ss$ and the one-loop Higgs decay $h\to μ^+ μ^-$.
