An automated framework for hierarchical reconstruction of B mesons at the Belle II experiment

TL;DR

This paper introduces an automated software framework for hierarchical reconstruction of B mesons at the Belle II experiment, enabling efficient and high-precision analysis of B meson decays with minimal user intervention.

Contribution

It presents a novel automated hierarchical reconstruction framework utilizing multivariate classifiers, improving efficiency and coverage of B meson decay modes in Belle II data analysis.

Findings

High signal-to-background ratio achieved in decay channels

Automated reconstruction reduces user intervention

Framework adaptable for analysis-specific selections

Abstract

We present a software framework for Belle II that reconstructs B mesons in many decay modes with minimal user intervention. It does so by reconstructing particles in user-supplied decay channels, and then in turn using these reconstructed particles in higher-level decays. This hierarchical reconstruction allows one to cover a relatively high fraction of all B decays by specifying a limited number of particle decays. Multivariate classification methods are used to achieve a high signal-to-background ratio in each individual channel. The entire reconstruction, including the application of pre-cuts and classifier trainings, is automated to a high degree and will allow users to retrain to account for analysis-specific signal-side selections.