Köln 2025 – scientific programme
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HK: Fachverband Physik der Hadronen und Kerne
HK 41: Hadron Structure and Spectroscopy V
HK 41.4: Talk
Thursday, March 13, 2025, 14:45–15:00, HS 3 Physik
Comparison of Sideband-Subtraction Methods for the Background Subtraction in ηc Decays — Tessa Bertelsmeier, Jans Böing, Anja Brüggemann, Lotta Frese, Nikolai in der Wiesche, Lois Kröger, •Hannah Neuwirth, Frederik Weidner, and Alfons Khoukaz for the BESIII Germany collaboration — Universität Münster, Germany
In particle physics, an accurate separation of signal and background events is essential to obtain reliable results. In particular, irreducible background contributions make it difficult to determine whether an event contributes to signal or background.
This study compares the strengths and limitations of two background subtraction methods: the single weight sideband subtraction and the Q-value method. The first method statistically removes background contributions from defined sideband regions, assuming similar properties of the background in sideband and signal regions. The second method calculates event-by-event probability-based weights by analysing local phase space neighbourhoods in a certain reference coordinate, allowing the separation of signal and background.
Using the world’s largest J/ψ data set from the BESIII experiment, the methods are applied to Monte Carlo simulations and experimental data of the J/ψ → γ (ηc → η′ K+ K− ) decay to remove non- η′ background, which is crucial for further analysis.
The current status of the analysis will be presented.
This work is supported by the German Research Foundation (DFG) under the project number 547123630 and the DFG GRK 2149/2.
Keywords: Charmonium; Light Meson; BESIII; Sideband Subtraction; Q-Value Method