Analysis of rare B meson decays at the Japanese B meson factory experiment Belle exploiting new neural full reconstruction algorithms

在B工厂，电子和正电子以几乎总是只产生一对B介子的能量碰撞。日本加速器KEKB的BELLE实验用过去10年收集的数据集保持了重建B介子的世界纪录。到目前为止，对这些数据的许多分析已经在很大程度上证实了粒子物理标准模型，包括衰变率，粒子反粒子振荡，以及根据2008年获得诺贝尔奖的小林和益川的理论违反CP对称。然而，如果测量精度进一步提高，标准模型的许多流行扩展，例如超对称，可能会出现。申请人基于贝叶斯统计和71个神经网络系统开发了一个新的1042个B衰变通道的分层重建方案，以最大限度地利用一个完全重建的B介子的数据集。应用该软件，我们可以在完全重建的基础上，将分析的有效光度提高一倍以上，相当于多年的额外数据采集。有了这个提议，我们希望确保我们可以在物理输出方面利用我们的软件创新。我们建议对罕见的B衰变进行一些数据分析，特别是从B介子的完全重建中受益，这只有在B工厂才能实现，因此可以补充其他实验在不久的将来进行，例如LHC包括LHCb。

At B factories electrons and positrons are collided at an energy where almost always only a pair of B mesons is produced. The BELLE experiment at the Japanese accelerator KEKB holds the world record in reconstructed B mesons with a data set collected in the last 10 years. So far many analyses of this data have confirmed the Standard Model of Particle Physics to a large accuracy, including decay rates, particle antiparticle oscillations, and violations of the CP symmetry in accordance with the theory of Kobayashi and Maskawa, who were honoured in 2008 with the Nobel Prize. However, many popular extensions of the Standard Model, e.g. Supersymmetry, could show up if the measurements precision is further improved.The applicants have developed a new hierarchical reconstruction scheme of 1042 B decay channels, based on Bayesian statistics and a system of 71 neural networks, to maximise the data set with one fully reconstructed B meson. Applying this software we could more than double the effective luminosity for analyses relying on full reconstruction, corresponding to many years of additional data taking.With this proposal we wish to make sure that we can exploit our software innovation in terms of physics output. We propose to perform several data analyses on rare B decay especially profiting from the full reconstruction of B mesons, which is only possible at B factories and therefore complementary to other experiments to be performed in the near future, such as LHC including LHCb.