Lattice calculations for Double Parton Distributions (DPDs)

特别是对于大型强子对撞机上的质子-质子碰撞，双部分子相互作用(DPI)做出了重大贡献，在双部分子相互作用中，每个碰撞质子中的一个部分子不仅经历了硬散射，而且同时经历了两对。对于这样的反应，干扰效应是相关的。虽然目前对这类反应的理论QCD描述已经很成熟了(也是我们自己的)，但用于描述这些反应的双部分子分布(DPD)却鲜为人知。因此，计算包括DPI在内的标准模型预测涉及很大的不确定性，这使得识别标准模型之外的物理更加困难。由于DPD是真正的非微扰物体，仅靠实验数据不足以确定它们，它们只能通过格子QCD模拟获得。在过去的几年里，我们已经开发和应用了所需的技术，最近发表了关于质子DPD的第一批结果。我们想继续这些计算。为了做到这一点，我正在申请一个博士职位。

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.