We apply the on-shell amplitude techniques in the domain of dark matter. Without evoking fields and Lagrangians, an effective theory for a massive spin-$S$ particle is defined in terms of on-shell amplitudes, which are written down using the massive spinor formalism. This procedure greatly simplifies the study of theories with a higher-spin dark matter particle. In particular, it provides an efficient way to calculate the rates of processes controlling dark matter production, and offers better physical insight into how different processes depend on the relevant scales in the theory. We demonstrate the applicability of these methods by exploring two scenarios where higher-spin DM is produced via the freeze-in mechanism. One scenario is minimal, involving only universal gravitational interactions, and is compatible with dark matter masses in a very broad range from sub-TeV to the GUT scale. The other scenario involves direct coupling of higher-spin DM to the Standard Model via the Higgs intermediary, and leads to a rich phenomenology, including dark matter decay signatures.

中文翻译：

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高旋转暗物质的壳有效理论

我们在暗物质领域应用壳上振幅技术。在没有引起磁场和拉格朗日派的情况下，有效的自旋$ S $粒子的理论是根据壳上振幅来定义的，该振幅是使用大量的自旋形式来写下来的。该程序极大地简化了具有更高自旋暗物质颗粒的理论研究。特别是，它提供了一种有效的方法来计算控制暗物质产生的过程的速率，并提供了更好的物理洞察力，以了解不同过程如何依赖于理论中的相关标度。我们通过探索两种通过冻结机制生产高转速DM的方案来证明这些方法的适用性。一种情况是最小的，仅涉及万有引力相互作用，并与从TeV到GUT标度的很大范围的暗物质质量兼容。另一种情况涉及通过希格斯媒介将较高转速的DM直接耦合到标准模型，并导致丰富的现象学，包括暗物质衰变特征。