Precision measurements of B->DDX and b->sll processes at LHCb

用欧洲核子研究中心大型强子对撞机上的LHCb探测器对B0&GT；K pi穆穆和相关衰变的分析表明，与SM的4西格玛张力与新的矢量粒子的存在是相容的。由于这种衰变是通过量子环跃迁进行的，它们对重的新粒子很敏感，而这些粒子可能不可能在大型强子对撞机(LHC)上直接产生。尽管这些测量构成了对SM的重大偏离，但声称新基本粒子的真正发现可能会受到强力(强子效应)出人意料的巨大非微扰效应的阻碍。这些效应可以影响B0-&Kpi穆穆和相关衰变的性质，模拟新粒子的存在。鉴于与SM的张力和B0&K pi穆穆及其相关衰变对新物理现象影响的敏感性，进一步探索这种跃迁势在必行。LHCb实验积累了大量的B介子衰变，这无疑是粒子物理学领域的一场革命。目前的实验精度已经开始挑战SM预测中最基本的假设，包括直到最近还被认为是最先进的强大作用力的计算。有效分析如此大型数据集的唯一方法是利用Bristol广泛的幅度分析专业知识与高级机器学习技术相结合。这些复振幅拟合的性质是一项计算密集型任务，最大限度地受益于高度并行的计算系统，如图形处理单元(GPU)。这位博士生将带头开发第一个依赖于GPU的四体稀有B介子衰变的幅度拟合框架。

Analyses of B0 -> K pi mu mu and related decays using the LHCb detector at CERN's LHC, have revealed a > 4sigma tension with the SM that is compatible with the existence of a new vector-particle. As such decays proceed via a quantum-loop transition, they are sensitive to heavy new particles which may be impossible to create directly at the Large Hadron Collider (LHC). Although these measurements constitute a significant deviation from the SM, claiming a genuine discovery of a new fundamental particle could be hindered by unexpectedly large non-perturbative effects of the strong-force (hadronic effects). These effects can influence the properties of B0 -> K pi mu mu and related decays, mimicking the presence of a new particle. In light of both the tension with the SM and the sensitivity of B0 -> K pi mu mu and related decays to the effects of new physics phenomena, further exploration of such transitions is imperative. The large number of B-meson decays amassed by the LHCb experiment has resulted in nothing short of a revolution in the field of particle physics. The current experimental precision has started to challenge even the most basic of assumptions in SM predictions, including calculations of the strong force that until recently were considered state-of-the art. The only way to effectively analyse such larger datasets is to make use of Bristol's extensive amplitude analysis expertise combined with Advanced Machine Learning techniques. The nature of these complex amplitude fits are a computationally intensive task that maximally benefits from highly parallelised computing systems such as Graphics Processing Units (GPUs). The PhD candidate will spearhead the development of the first amplitude fit framework for 4-body rare B-meson decays that relies on GPUs.