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arXiv 2212.09759hep-ph
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食人暗物质的定义域

The domain of a cannibal dark matter

Marco Hufnagel, Michel H. G. Tytgat

AI总结:

本文研究了隐藏 sector 中具有自发对称破缺的实标量食人暗物质模型,计算了其热平均湮灭截面,发现热候选者遵循反常标度律,并讨论了宇宙学和天体物理学约束。

摘要:

我们考虑一种暗物质单独存在于隐藏 sector 的场景,它由具有显式或自发破缺的 $\mathbb{Z}_2$ 对称性的实标量粒子组成,其温度与可见 sector 的温度不同,即 $T' \neq T$。尽管具有一般耦合的类似模型已在文献中被研究过,但具有自发对称破缺的模型这一特例构成了这些结果的非平凡极限,因为它在阈值处对于 $k > 2$ 的过程 $k \rightarrow 2$ 具有消失的树阶振幅,从而使控制暗物质冻结速度的截面受到抑制。我们仔细确定了该场景下热平均暗物质湮灭截面,包括单圈修正和玻色-爱因斯坦统计的可能效应,同时还在热暗物质候选者的定义域中报告了我们的结果,即 $T'_\text{fo}/T$ 与 $m_\text{DM}$ 的关系,其中 $T'_\text{fo}$ 是退耦时隐藏 sector 的温度。我们表明,对于固定的四次耦合,由于熵守恒,热候选者位于曲线 $T'/T \propto m_\text{DM}^{-1/3 (1+κ)}$ 上,具有反常标度 $κ\sim \mathcal{O}(T'_\text{fo}/m_\text{DM}) > 0$。此外,我们证明该标度对于广泛的食人 DM 场景类都是有效的,无论是否具有对称破缺。此外,我们还讨论了相关的宇宙学和天体物理学约束。

英文摘要:

We consider a scenario in which the dark matter is alone in a hidden sector and consists of a real scalar particle with a manifest or spontaneously broken $\mathbb{Z}_2$ symmetry, at a temperature which differs from the one of the visible sector, $T' \neq T$. While similar models with general couplings have already been studied in the literature, the special case of a model with spontaneous symmetry breaking constitutes a non-trivial limit of these results, since it features vanishing tree-level amplitudes for the processes $k \rightarrow 2$ with $k>2$ at threshold, thus making the cross-section governing dark-matter freeze-out velocity suppressed. We carefully determine the thermally averaged dark-matter annihilation cross-section in this scenario, including the possible effects of one-loop corrections and Bose-Einstein statistics, while also reporting our results in the domain of thermal dark matter candidates, $T'_\text{fo}/T$ vs. $m_\text{DM}$ with $T'_\text{fo}$ being the hidden-sector temperature at decoupling. We show that for fixed quartic coupling, due to entropy conservation, the thermal candidates lie along a curve $T'/T \propto m_\text{DM}^{-1/3 (1+κ)}$ with anomalous scaling $κ\sim \mathcal{O}(T'_\text{fo}/m_\text{DM}) > 0$. Furthermore, we demonstrate that this scaling is valid for a broad class of cannibal DM scenarios, with or without symmetry breaking. In addition, we also discuss the relevant cosmological and astrophysical constraints.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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