Lattice calculations for Double Parton Distributions (DPDs)

特别是在大型强子对撞机的质子-质子碰撞中，双部分子相互作用（DPIs）的贡献很大，在这种反应中，每个碰撞质子不仅有一个部分子经历硬散射，而且有两个部分子同时经历硬散射。对于这种反应，干涉效应是相关的。虽然目前这类反应的QCD理论描述还很发达（我们也是如此），但参数化它们的双Parton分布（DPDs）却很少为人所知。因此，计算包括dpi在内的标准模型预测涉及重大的不确定性，这使得识别超出标准模型的物理更加困难。由于dpd是真正的非摄动对象，单独的实验数据不足以确定它们，因此它们只能从晶格QCD模拟中获得。在过去的几年里，我们已经开发并应用了所需的技术，最近发表了质子DPDs的第一批结果。我们要继续这些计算。为此，我申请了一个博士职位。

In particular for proton-proton collisions at LHC there are significant contributions from Double Parton Interactions (DPIs), which are reactions in which not only one parton from each colliding proton undergoes a hard scattering, but two pairs simultaneously. For such reactions interference effects are relevant. While at present the theoretical QCD description of such reactions is far developed (also by us), the Double Parton Distributions (DPDs) which parameterize them are hardly known. Therefore, calculating Standard Model predictions including DPIs involves significant uncertainties which makes the identification of physics beyond the standard model more difficult. Because DPDs are genuinely non-perturbative objects and experimental data alone is insufficient to determine them, they can only be obtained from Lattice QCD simulations. We have developed and applied the needed techniques over the last years and have recently published first results for proton DPDs. We want to continue these calculations. To do so I am applying for one PhD position.