Measurement of CP violation with B0->Dpi+pi- decays

衰变通道B0->Dpi+pi-，其中中性D介子在CP特征态最终态K+K-和pi+pi-中重建，可以用来在理论上明确地确定Cabibbo-Kobayashi-Maskawa夸克混合矩阵的角β。这样做需要详细了解B0->D0barpi+pi-衰变的Dalitz图分布，其中D0bar->K+pi-衰变是最合适的。在这个项目中，实现了具有所有中性D介子衰变的模式的一种新颖的同时衰变时间依赖分析。这种方法允许控制达利茨地块建模以及实验效果，如腐烂时间接受和风味标签校准。该分析将使用大型强子对撞机运行1和运行2期间LHCb实验收集的数据样本来实施，并有望在理论上清洁通道中获得最精确的角度beta测定。

The decay channel B0->Dpi+pi-, where the neutral D meson is reconstructed in the CP eigenstate final states K+K- and pi+pi-, can be used to make a theoretically clean determination of the angle beta of the Cabibbo-Kobayashi-Maskawa quark mixing matrix. Doing so requires detailed understanding of the Dalitz plot distribution of B0->D0barpi+pi- decays, for which the D0bar->K+pi- decay is the most appropriate. In this project, a novel simultaneous decay-time-dependent analysis of the modes with all neutral D meson decays is implemented. This approach allows control of the Dalitz plot modelling as well as experimental effects such as decay-time acceptance and flavour tagging calibration. The analysis will be implemented using the data sample collected with the LHCb experiment during Runs 1 and 2 of the Large Hadron Collider, and is expected to lead to the most precise determination of the angle beta in theoretically clean channels.