近阈值卡鲁扎-克莱因引力子衰变与暗维度
Near Threshold Kaluza-Klein Graviton Decays and the Dark Dimension
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中文总结 AI 辅助
该研究指出近阈值KK引力子衰变为纯d波，速率与动量五次方成正比，排除了其作为暗物质候选，并利用产生的MeV伽马射线约束再加热温度，要求额外维度半径远小于距离猜想预期。
中文摘要 AI 辅助
在近阈值条件下，卡鲁扎-克莱因（KK）引力子的塔内衰变是纯$d$波，其速率$\Gamma \propto p^5$，其中$p$是衰变产物的动量，而非暗维度文献中假设的$s$波速率$\Gamma \propto p$。在平坦暗维度中，这一结果排除了KK引力子作为暗物质候选者的可能性。即使假设存在其他暗物质来源，KK引力子不可避免的冻结-入丰度会产生MeV伽马射线，从而允许人们对再加热温度设定上限；此外，利用大爆炸核合成和宇宙微波背景对再加热温度的下限，要求额外维度的半径比距离猜想天真预期的值小近三个数量级，即$R\sim \Lambda^{-1/4}$。
英文摘要
Near threshold, intra-tower decays of Kaluza-Klein (KK) gravitons are pure $d$-wave, with rate $Γ\propto p^5$ in the decay products momentum $p$, rather than the $s$-wave $Γ\propto p$ assumed in the dark dimension literature. In a flat dark dimension this excludes KK gravitons as a dark matter candidate. Even if some other source of dark matter is assumed, the irreducible freeze-in abundance of KK gravitons produce MeV gamma rays which allows one to set upper limits on the reheating temperature; additionally using the lower bound on the reheating temperature from big-bang nucleosynthesis and the cosmic microwave background requires the radius of the extra dimension to be almost three orders of magnitude smaller than the distance conjecture would naively prefer, $R\sim Λ^{-1/4}$.
发表机构
- Center for Theoretical Physics – a Leinweber Institute, Massachusetts Institute of Technology（麻省理工学院莱因韦伯理论物理中心）
机构由 AI 辅助整理，请以论文原文为准。
