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arXiv 1610.07545hep-ph
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用有效场论方法在LHC表征暗物质

Dark Matter characterization at the LHC in the Effective Field Theory approach

Alexander Belyaev, Luca Panizzi, Alexander Pukhov, Marc Thomas

摘要:

我们研究了标量、费米子和矢量暗物质与SM夸克和胶子相互作用的五维和六维有效算符的完整集合,以探索在LHC上区分这些算符和确定DM自旋的可能性.我们发现,三个因素--算符的有效维度、算符的SM部分的结构以及与算符相连的SM粒子的部分子密度--唯一地定义了粒子的形状。(不可观察的)DM对的不变质量分布,因此,使用$χ^2$分析,我们发现,在LHC上,在300 fb $^{-1}$的光度下,某些类别的EFT算子可以彼此区分。因此,由于DM自旋部分与确定MET形状的因素相关,LHC也可能揭示DM自旋。我们还观察到,(高达两个数量级)的大MET削减方案与不同的DM自旋,从而表明DM发现的潜力强烈依赖于它。我们在这里进行的研究可以应用更普遍的比EFT范式内,其中DM介质不产生的质量壳,例如t通道介体或质量低于$2M_{DM}$的介体的情况,其中DM对的不变质量不固定。

英文摘要:

We have studied the complete set of dimension 5 and dimension 6 effective operators involving the interaction of scalar, fermion and vector Dark Matter (DM) with SM quarks and gluons, to explore the possibility to distinguish these operators and characterise the spin of DM at the LHC. We have found that three factors - the effective dimension of the operator, the structure of the SM part of the operator and the parton densities of the SM particles connected to the operator - uniquely define the shape of the (unobservable) invariant mass distribution of the DM pair and, consequently, the shape of the (observable) MET distribution related to it. Using $χ^2$ analysis, we found that at the LHC, with a luminosity of 300 fb$^{-1}$, certain classes of EFT operators can be distinguished from each other. Hence, since DM spin is partly correlated with the factors defining the shape of MET, the LHC can potentially shed a light also on DM spin. We have also observed a drastic difference in the efficiencies (up to two orders of magnitude) for large MET cuts scenarios with different DM spin, thus indicating that the DM discovery potential strongly depends on it. The study we perform here can be applied more generally than within the EFT paradigm, where the DM mediator is not produced on-the-mass-shell, such as the case of t-channel mediator or mediator with mass below $2M_{DM}$, where the invariant mass of the DM pair is not fixed.

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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