Heidelberg 2022 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

T: Fachverband Teilchenphysik

T 30: Flavour Physics 3

T 30.9: Vortrag

Dienstag, 22. März 2022, 18:15–18:30, T-H15

Optimization of the K_L⁰ detection and rejection at Belle II — Florian Bernlochner, Jochen Dingfelder, Peter Lewis, and •Lucas Stötzer for the Belle II collaboration — Physikalisches Institut der Rheinischen Friedrich-Wilhelms-Universität Bonn

We investigate an optimization of the reconstruction of K_L⁰ mesons in the Belle II experiment. K_L⁰ mesons are challenging to detect and identify because they are chargeless, and due to their long lifetime they typically do not decay within the Belle II detector. The main way to detect them is via hadronic showers in the K-Long-Muon detector (KLM). However, the detection efficiency is low and background clusters are common, which limits the usability of the KLM clusters in physics analyses. Thus, we seek to improve the discrimination between KLM clusters produced by K_L⁰ showers and background sources using a clean sample of K_L⁰ mesons from the process e⁺e⁻→γ_ISR[φ→ K_L⁰K_S⁰]. The K_S⁰ will mainly decay to two charged pions. Thus, by finding the high energy photon (γ_ISR) and reconstructing the K_S⁰ from the pions, the four-momentum of the K_L⁰ can be inferred. This allows for a direct comparison between KLM clusters from K_L⁰ and background sources. Further, we investigate whether K_L⁰ showers deposited in the electromagnetic calorimeter can be used to improve the K_L⁰ detection efficiency while maintaining high purity.