Optimization of Geant4 for the Belle II software library

During the next decade, the SuperKEKB/Belle II experiment expects to collect almost two orders of magnitude more collision data than the previous generation B-Factory experiments. Study of this data requires monumental computing resources to process and to generate the required simulation events necessary for physics analysis. At the core of the Belle II simulation library is the Geant4 toolkit. To use the available computing resources more efficiently, the physics list for Geant4 has been optimized for the Belle II environment, and various other strategies were applied to improve the performance of the Geant4 toolkit in the Belle II software library. Following the inclusion of this newly optimized physics list in an updated version of Geant4 toolkit, we obtain much better CPU usage during event simulation and reduce the computing resource usage by ~ 44%.

The inclusive reconstruction of Charmed Mesons on B-factory

We present the study of the inclusive branching ratios of the double charmed decays with strangeness B → $ \overline D ^{^{(*)} } D_{s(J)}^{(*)} $ The study based on the missing mass distributions in inclusive transitions B → $ \overline D ^{^{(*)} } X $, and thus in a way free from the assumptions about resonance decays $ D_{s(J)}^{(*)} $. There are also presented the perspective of such studies on the next generation Belle II experiment.

Exotic and Conventional Bottomonium Physics Prospects at Belle II

The Belle II experiment, being constructed at the KEK laboratory in Japan, represents a substantial upgrade of both the Belle detector and the KEKB accelerator. It is expected that Belle II will collect 50 times more data than existing B-Factory samples beginning in 2019. Belle II is uniquely capable of studying the so-called "XYZ" particles: heavy exotic hadrons consisting of more than three quarks. First discovered by Belle, these now number in the dozens, and represent the emergence of a new category within Quantum Chromodynamics. In this article we summarize the capabilities of Belle II to explore both exotic and conventional bottomonium physics, with a particular focus on the physics reach of the first data, where opportunities exist to make an immediate impact in this area.