Measurement of the CKM angle in B-->D*K decays

CKM角γ仍然是风味物理学中最有趣的参数之一。它可以通过各种各样的B ->DX型衰变来访问。本计画将研究衰变链B->D*h，D->Kshh，其中h代表π介子或K介子。D->Kshh方法涉及Dalitz图上衰变分布的研究，并通过结合来自BESIII的独立于模型的信息，允许对角度γ进行独立测量。预计这将具有良好的精度，但这种测量的全部功率将在与其他D衰减模式的组合中实现，这些模式可能会受到多种解决方案的影响。在这个项目中，将考虑D* 的两种衰变，并使用它们之间的180度强相位。π介子和光子将不会被重建。这导致更复杂的不变质量分布，但效率显著提高。使用这种潜在的强大的部分重建技术，没有从这种衰变模式进行测量。该项目所面临的挑战将包括护理参数化的许多类似的背景衰减和优化的工作点和调查的拟合过程中，迭代的方法可能是有用的。该项目还将包括使用LHC B运行3的数据测量B->Dh衰变中的伽马。这将需要作出相当大的努力，以了解这一新探测器的数据质量和行为。将特别关注PID校准，这将影响LHCb的所有其他早期测量，其中研究的校准通道（D*-> D 0 pi）将用于为所有测量提供校准数据。

The CKM angle gamma remains one of the most interesting parameters in flavour physics. It can be accessed through a wide variety of B ->DX style decays. This project will study the decay chain B->D*h, D->Kshh where in each case h represents either a pion or a kaon. The D->Kshh method involves the study of the distribution of the decay over the the Dalitz plot, and through combination of model-independent information from BESIII allows for a standalone measurement of the angle gamma. This is expected to be of good precision, but the full power of this measurement will be realised in the combination with other D decay modes which can suffer from multiple solutions. In this project both decays of the D* will be considered and use is made of the 180 degree strong phase between them. The pion and photon will not be reconstructed. This results in a more complicated invariant-mass distribution, but at a significant gain of efficiency. No measurements from this decay mode using this potentially powerful partial reconstruction technique have been performed. The challenges faced by this project will include care parameterisation of many similar background decays and optimising the working point and an investigation into the fit procedure where an iterative approach may be useful. The results are expected to be high impact.The project will also encompass a measurement of gamma in B->Dh decays using data from LHCb Run3. This will require considerable effort in understanding the quality and behaviour of the data from this new detector. Particular focus will be given to the PID calibration which will impact all other early measurements from LHCb where the calibration channel studied (D*->D0pi) will be used to provide calibration data for all measurements.