In the simplified dark matter models commonly studied, the mass generation mechanism for the dark fields is not typically specified. We demonstrate that the dark matter interaction types, and hence the annihilation processes relevant for relic density and indirect detection, are strongly dictated by the mass generation mechanism chosen for the dark sector particles, and the requirement of gauge invariance. We focus on the class of models in which fermionic dark matter couples to a spin-1 vector or axial-vector mediator. However, in order to generate dark sector mass terms, it is necessary in most cases to introduce a dark Higgs field and thus a spin-0 scalar mediator will also be present. In the case that all the dark sector fields gain masses via coupling to a single dark sector Higgs field, it is mandatory that the axial-vector coupling of the spin-1 mediator to the dark matter is non-zero; the vector coupling may also be present depending on the charge assignments. For all other mass generation options, only pure vector couplings between the spin-1 mediator and the dark matter are allowed. If these coupling restrictions are not obeyed, unphysical results may be obtained such as a violation of unitarity at high energies. These two-mediator scenarios lead to important phenomenology that does not arise in single mediator models. We survey two-mediator dark matter models which contain both vector and scalar mediators, and explore their relic density and indirect detection phenomenology.
We introduce simplified models for enhancements in the matter power spectrum at small scales and study their implications for dark matter substructure and gravitational observables. These models capture the salient aspects of a variety of early universe scenarios that predict enhanced small-scale structure, such as axion-like particle dark matter, light vector dark matter, and epochs of early matter domination. We use a model-independent, semi-analytic treatment to map bumps in the matter power spectrum to early-forming sub-solar mass dark matter halos and estimate their evolution, disruption,…
In this paper we study the possible searches at colliders using Vector Boson Fusion topology in the context of Simplified Models signatures. We examine the possible physics reach of these searches with regard to monojet-type searches, and determine how these two signatures are complementary.
Simplified Models for Dark Matter Face their Consistent Completions
简化的暗物质模型最近被提倡作为一个强有力的工具，利用暗物质直接探测，间接探测和LHC实验探针之间的互补性。专注于赝标量介质之间的黑暗和可见的部门，我们表明，简化的暗物质模型的现象学偏离一致的${SU(2)_{\mathrm{L}} \times U(1)_{\mathrm{Y}}}$规范不变完成显着。我们讨论了简化模型未能捕捉到的关键物理，以及它对LHC搜索的影响。值得注意的是，我们表明，共振单Z搜索提供竞争力的灵敏度，标准的单射流分析在$13$ TeV LHC。
Simplified Dark Matter Models for the Galactic Center Gamma-Ray Excess
从银河系中心周围的区域观察到的伽马射线过剩的动机，我们探索粒子暗物质模型，可能占频谱和归一化的信号。采取模型独立的方法，我们认为一个详尽的列表的树级图的暗物质湮灭，并确定可以解释所观察到的伽马射线发射，同时预测热遗迹丰度等于测得的宇宙学暗物质密度。我们确定了各种各样的模型，可以满足这些标准，而不与现有的直接检测实验或大型强子对撞机（LHC）的约束冲突。在不久的将来的暗物质实验和/或即将到来的14 TeV LHC检测的前景显得相当有希望。
We present a calculation of the next-to-leading order QCD corrections for the scattering of Dark Matter particles off nucleons in the framework of simplified models with s- and t-channel mediators. These results are matched to the Wilson coefficients and operators of an effective field theory that is generally used for the presentation of experimental results on spin-independent and spin-dependent direct detection rates. Detailed phenomenological studies illustrate the complementary reach of collider searches for Dark Matter and the direct detection experiments CRESST and XENON. In the case of…
A comprehensive analysis of cosmological and collider constraints is presented for three simplified models characterised by a dark matter candidate (real scalar, Majorana fermion and real vector) and a coloured mediator (fermion, scalar and fermion respectively) interacting with the right-handed up quark of the Standard Model. Constraints from dark matter direct and indirect detection and relic density are combined with bounds originating from the re-interpretation of a full LHC run 2 ATLAS search targeting final states with multiple jets and missing transverse energy. Projections for the high…
Beyond the Standard Model physics is required to explain both dark matter and the baryon asymmetry of the universe, the latter possibly generated during a strong first-order electroweak phase transition. While many proposed models tackle these problems independently, it is interesting to inquire whether the same model can explain both. In this context, we link state-of-the-art perturbative assessments of the phase transition thermodynamics with the extraction of the dark matter energy density. These techniques are applied to a next-to-minimal dark matter model containing an inert Majorana ferm…
We review simplified models in which a singlet Majorana dark matter candidate couples to Standard Model (SM) fermions through interactions mediated by scalar fermion partners. We summarize the two primary production mechanisms in these scenarios: dark matter annihilation mediated by first or second generation scalar fermion partners with significant left-right chiral mixing and co-annihilation with scalar fermion partners nearly degenerate in mass with the dark matter. We then highlight the most interesting phenomenological aspects of charged mediator models relevant for current and future sea…
The existence of a dark matter model with a rich dark sector could be the reason why WIMP dark matter has evaded its detection so far. For instance, colored co-annihilation naturally leads to the prediction of heavier dark matter masses. Importantly, in such a scenario the Sommerfeld effect and bound state formation must be considered in order to accurately predict the relic abundance. Based on the example of the currently widely studied $t$-channel simplified model with a colored mediator, we demonstrate the importance of considering these non-perturbative effects for correctly inferring the …
