NνDEx aims to search for the neutrinoless double beta decay in 82Se using a high pressure 82SeF6 gas time projection chamber (TPC). This paper presents a simulation and analysis framework developed specifically for the NνDEx experiment. Using density functional theory and two-temperature theory, the reduced mobilities of SeF5− and SeF6− ions in SeF6 were calculated, yielding values of 0.444 and 0.430 cm2V−1s−1 respectively, with an estimated uncertainty within 3\%. The TPC geometry, featuring a cathode, focusing plane, and anode structure, was modeled in COMSOL to compute electric fields. Signal and background events were generated using BxDecay0 and Geant4, while Garfield++ was employed to simulate charge transport and signal induction. Three-dimensional tracks were reconstructed from drift-time differences between the two assumed ion species using a breadth-first search algorithm. To demonstrate the framework's analytical capability, topological variables were taken from reconstructed tracks and used to define selection criteria. A boosted decision tree was then implemented to benchmark the signal-background separation. This simulation framework successfully validates the complete experimental workflow, serving as a robust tool for detector design and future sensitivity studies in the NνDEx experiment.
@article{arxiv.2508.13582,
title = {Development of a simulation and analysis framework for N{\nu}DEx experiment},
author = {Tianyu Liang and Hulin Wang and Dongliang Zhang and Chaosong Gao and Xiangming Sun and Feng Liu and Jun Liu and Chengui Lu and Yichen Yang and Chengxin Zhao and Hao Qiu and Kai Chen},
journal= {arXiv preprint arXiv:2508.13582},
year = {2026}
}