Kink Finder at Belle II

TL;DR

This paper introduces a specialized track-finding algorithm for Belle II that effectively detects in-flight decays or scatterings of charged particles, significantly improving detection efficiency and accuracy over standard methods.

Contribution

The paper presents a novel Kink Finder algorithm that enhances detection of particle decay signatures and improves secondary track resolution in the Belle II experiment.

Findings

Reconstruction efficiency for kinks is about 40%.

Improved resolution of secondary track parameters.

Reduces PID misidentification rates for kaons and pions.

Abstract

We present a track-finding algorithm for the Belle II experiment that specifically targets so-called kinks: signatures of charged particles decaying or scattering in-flight in the detector material, resulting in a sudden and significant change of the particle's flight direction. Our benchmark studies of this Kink Finder show that the reconstruction efficiency for such signatures is about 40%, compared to a value of around 11% for the standard Belle II track-finding algorithm. Our studies also show that the Kink Finder significantly improves the resolution of the secondary track parameters, suppresses the number of cloned tracks, and reduces the PID misidentification rates for kaon and pions.