We study several simplified dark matter (DM) models and their signatures at the LHC using neural networks. We focus on the usual monojet plus missing transverse energy channel, but to train the algorithms we organize the data in 2D histograms instead of event-by-event arrays. This results in a large performance boost to distinguish between standard model (SM) only and SM plus new physics signals. We use the kinematic monojet features as input data which allow us to describe families of models with a single data sample. We found that the neural network performance does not depend on the simulated number of background events if they are presented as a function of $S/\sqrt{B}$, where $S$ and $B$ are the number of signal and background events per histogram, respectively. This provides flexibility to the method, since testing a particular model in that case only requires knowing the new physics monojet cross section. Furthermore, we also discuss the network performance under incorrect assumptions about the true DM nature. Finally, we propose multimodel classifiers to search and identify new signals in a more general way, for the next LHC run.
翻译:我们使用神经网络在LHC研究几种简化的暗物质(DM)模型及其特征。 我们侧重于通常的单喷射和缺失的跨反向能源频道,但是要培训算法,我们用2D直方图而不是逐个事件阵列来组织数据。 这导致一个很大的性能提升来区分标准模型(SM)和SM加新物理信号。 我们使用运动单体单体喷射功能作为输入数据, 使我们能够用一个数据样本来描述模型的家庭。 我们发现神经网络的性能并不取决于模拟的背景事件数量, 如果它们显示为美元/\\ sqrt{B}$的函数, 而美元和美元是每个直方图的信号和背景事件数量。 这为方法提供了灵活性, 因为在此情况下测试一个特定模型只需要了解新的物理单体截面部分。 此外, 我们还在对真实的DM性质错误假设下讨论网络性能。 最后,我们建议多个模型分类员以更笼统的方式搜索和识别新的信号, 用于下一个LHCS 运行 。