Topological background discrimination in the PandaX-III neutrinoless double beta decay experiment. (27th February 2020)

• Record Type: Journal Article
• Authors: Galan, J; Chen, X; Du, H; Fu, C; Giboni, K; Giuliani, F; Han, K; Jiang, B; Ji, X; Lin, H; Lin, Y; Liu, J; Ni, K; Ren, X; Wang, S; Wu, S; Xie, C; Yang, Y; Zhang, T; Zhao, L; Aune, S; Bedfer, Y; Berthoumieux, E; Calvet, D; d'Hose, N; Ferrer-Ribas, E; Kunne, F; Manier, B; Neyret, D; Papaevangelou, T; Chen, L; Hu, S; Li, P; Li, X; Zhang, H; Zhao, M; Zhou, J; Mao, Y; Qiao, H; Wang, S; Yuan, Y; Wang, M; Chen, Y; Khan, A N; Tang, J; Wang, W; Chen, H; Feng, C; Liu, J; Liu, S; Wang, X; Zhu, D; Castel, J F; Cebrián, S; Dafni, T; Irastorza, I G; Luzón, G; Mirallas, H; Sun, X; Tan, A; Haxton, W; Mei, Y; Kobdaj, C; Yan, Y;
• Is Part Of: Journal of physics. Volume 47:Number 4(2020:Apr.)
• Publication Date: 2020-02-27
• Subjects: neutrino -- PandaX-III -- topology -- pattern recognition -- Majorana -- mass -- double beta decay; Nuclear physics -- Periodicals; Particles (Nuclear physics) -- Periodicals; Physique nucléaire -- Périodiques; Particules (Physique nucléaire) -- Périodiques; Kernfysica; Elementaire deeltjes; 539.7
• DOI: 10.1088/1361-6471/ab4dbe
• Languages: English
• ISSNs: 0954-3899

Abstract

Abstract: The PandaX-III experiment plans to search for neutrinoless double beta decay (0 νββ ) of 136 Xe in the China JinPing underground Laboratory (CJPL). The experiment will use a high pressure gaseous time projection chamber (TPC) to register both the energy and the electron track topology of an event. This article is devoted to demonstrate our particular detector setup capabilities for the identification of 0 νββ and the consequent background reduction. As software tool we use REST, a framework developed for the reconstruction and simulation of TPC-based detector systems. We study the potential for background reduction by introducing appropriate parameters based on the properties of 0 νββ events. We exploit for the first time not only the energy density of the electron track-ends, but also the electron scattering angles produced by an electron near the end of its trajectory. To implement this, we have added new algorithms for detector signal and track processing inside REST. Their assessment shows that background can be reduced by about 7 orders of magnitude while keeping 0 νββ efficiency above 20% for the PandaX-III baseline readout scheme, a two-dimensional 3 mm pitch stripped readout. More generally, we use the potential of REST to handle 2D/3D data to assess the impact on signal-to-background significance at different detector granularities, and to validate the PandaX-III baseline choice. Finally, we demonstrate the additional potential to discriminate surface background events generated at the readout plane in the absence of t o, by making use of event parameters related with the diffusion of electrons.