发表机构
Università della Calabria（卡拉布里亚大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文研究标量单态暗物质通过x通道与标准模型相互作用，该机制使希格斯门户在树级和单圈级均被抑制，并探讨了最小实现下对撞机、希格斯、味及天体物理约束的互补性，发现存活参数区主要在暗物质重于带电中介子的区域。
AI 中文摘要
在本文中，我研究了一类情景，其中标量单态暗物质候选者与标准模型的相互作用方式使得希格斯门户即使在圈层也被强烈抑制，这是通过一种涉及标量中介子的特定机制实现的。该中介子携带非平凡的规范或内部量子数，仅允许与暗物质发生四次耦合，并且属于没有能与希格斯玻色子混合的分量的表示，因此暗物质仅与奇异态相互作用。我将这种构造称为$x$-通道，因为在暗区与可见区之间没有单个中介子被交换，以区别于标准的$s$-通道和$t$-通道简化情景。这种抑制源于跑动希格斯门户耦合的一个边界条件，该条件使得树级和单圈希格斯介导的贡献在零动量转移时消失，无论中介子的内部量子数如何。我在此考虑一个最小实现，其中中介子是单电荷或双电荷的无色$SU(2)_L$单态标量，衰变为轻子，并研究对撞机、希格斯、味以及天体物理/宇宙学约束之间的互补性。在所扫描的范围内和基准假设下，存活的点主要位于暗物质比带电标量中介子更重的区域。LHC限制决定了该区域的下边缘，其部分可通过未来对撞机通过产生带电标量来探测。$x$-通道的其他实现可以开辟不同的现象学方向以供探索。
英文摘要
In this paper I study a class of scenarios in which a scalar singlet dark matter candidate interacts with the Standard Model in such a way that the Higgs portal is strongly suppressed, even at loop level, through a specific mechanism involving scalar mediators. The mediator carries non-trivial gauge or internal quantum numbers that allow only a quartic coupling with the dark matter, and belongs to representations with no components that can mix with the Higgs boson, so that the dark matter interacts only with exotic states. I refer to this construction as $x$-channel because no single mediator is exchanged between the dark and visible sectors, to distinguish it from the standard $s$- and $t$-channel simplified scenarios. The suppression is due to a boundary condition on the running Higgs-portal coupling, which makes the tree-level and one-loop Higgs-mediated contributions vanish at zero momentum transfer, regardless of the internal quantum numbers of the mediator. I consider here a minimal realisation, in which the mediator is a singly- or doubly-charged colourless $SU(2)_L$-singlet scalar decaying to leptons, and study the complementarity between collider, Higgs, flavour, and astrophysical/cosmological constraints. Within the scanned ranges and benchmark assumptions, the surviving points are predominantly in the region where the dark matter is heavier than the charged scalar mediator. LHC limits determine the lower edge of this region, part of which can be probed by future colliders through the production of the charged scalars. Other realisations of the $x$-channel can open different phenomenological directions to explore.
Comments22 pages, 12 figures
