학술논문
Offline tagging of radon-induced backgrounds in XENON1T and applicability to other liquid xenon detectors
Document Type
Working Paper
Author
Aprile, E.; Aalbers, J.; Abe, K.; Maouloud, S. Ahmed; Althueser, L.; Andrieu, B.; Angelino, E.; Angevaare, J. R.; Martin, D. Antón; Arneodo, F.; Baudis, L.; Baxter, A. L.; Bazyk, M.; Bellagamba, L.; Biondi, R.; Bismark, A.; Brookes, E. J.; Brown, A.; Bruno, G.; Budnik, R.; Bui, T. K.; Cardoso, J. M. R.; Chavez, A. P. Cimental; Colijn, A. P.; Conrad, J.; Cuenca-García, J. J.; D'Andrea, V.; Garcia, L. C. Daniel; Decowski, M. P.; Di Donato, C.; Di Gangi, P.; Diglio, S.; Eitel, K.; Elykov, A.; Ferella, A. D.; Ferrari, C.; Fischer, H.; Flehmke, T.; Flierman, M.; Fulgione, W.; Fuselli, C.; Gaemers, P.; Gaior, R.; Galloway, M.; Gao, F.; Ghosh, S.; Glade-Beucke, R.; Grandi, L.; Grigat, J.; Guan, H.; Guida, M.; Hammann, R.; Higuera, A.; Hils, C.; Hoetzsch, L.; Hood, N. F.; Iacovacci, M.; Itow, Y.; Jakob, J.; Joerg, F.; Joy, A.; Kaminaga, Y.; Kara, M.; Kavrigin, P.; Kazama, S.; Kobayashi, M.; Kopec, A.; Kuger, F.; Landsman, H.; Lang, R. F.; Levinson, L.; Li, I.; Li, S.; Liang, S.; Lin, Y. T.; Lindemann, S.; Lindner, M.; Liu, K.; Loizeau, J.; Lombardi, F.; Long, J.; Lopes, J. A. M.; Luce, T.; Ma, Y.; Macolino, C.; Mahlstedt, J.; Mancuso, A.; Manenti, L.; Marignetti, F.; Undagoitia, T. Marrodán; Martens, K.; Masbou, J.; Masson, E.; Mastroianni, S.; Melchiorre, A.; Messina, M.; Michael, A.; Miuchi, K.; Molinario, A.; Moriyama, S.; Morå, K.; Mosbacher, Y.; Murra, M.; Müller, J.; Ni, K.; Oberlack, U.; Paetsch, B.; Palacio, J.; Pan, Y.; Pellegrini, Q.; Peres, R.; Peters, C.; Pienaar, J.; Pierre, M.; Plante, G.; Pollmann, T. R.; Principe, L.; Qi, J.; Qin, J.; García, D. Ramírez; Rajado, M.; Shi, J.; Singh, R.; Sanchez, L.; Santos, J. M. F. dos; Sarnoff, I.; Sartorelli, G.; Schreiner, J.; Schulte, D.; Schulte, P.; Eißing, H. Schulze; Schumann, M.; Lavina, L. Scotto; Selvi, M.; Semeria, F.; Shagin, P.; Shi, S.; Silva, M.; Simgen, H.; Takeda, A.; Tan, P. -L.; Terliuk, A.; Thers, D.; Toschi, F.; Trinchero, G.; Tunnell, C.; Tönnies, F.; Valerius, K.; Vecchi, S.; Vetter, S.; Volta, G.; Weinheimer, C.; Weiss, M.; Wenz, D.; Wittweg, C.; Wolf, T.; Wu, V. H. S.; Xing, Y.; Xu, D.; Xu, Z.; Yamashita, M.; Yang, L.; Ye, J.; Yuan, L.; Zavattini, G.; Zhong, M.; Zhu, T.
Source
Subject
Language
Abstract
This paper details the first application of a software tagging algorithm to reduce radon-induced backgrounds in liquid noble element time projection chambers, such as XENON1T and XENONnT. The convection velocity field in XENON1T was mapped out using $^{222}\text{Rn}$ and $^{218}\text{Po}$ events, and the root-mean-square convection speed was measured to be $0.30 \pm 0.01$ cm/s. Given this velocity field, $^{214}\text{Pb}$ background events can be tagged when they are followed by $^{214}\text{Bi}$ and $^{214}\text{Po}$ decays, or preceded by $^{218}\text{Po}$ decays. This was achieved by propagating a point cloud as directed by the velocity field, and searching for $^{214}\text{Bi}$ and $^{214}\text{Po}$ decays or $^{218}\text{Po}$ decays within a volume defined by the point cloud. In XENON1T, this tagging system achieved a $^{214}\text{Pb}$ background reduction of $6.2^{+0.4}_{-0.9}\%$ with an exposure loss of $1.8\pm 0.2 \%$. The tagging algorithm was also used to produce a population of tagged events with a large enhancement in the $^{214}\text{Pb}$ fraction. We show that the performance can be improved in XENONnT, and that the performance of such a software-tagging approach can be expected to be further improved in a diffusion-limited scenario. Finally, a similar method might be useful to tag the cosmogenic $^{137}\text{Xe}$ background, which is relevant to the search for neutrinoless double-beta decay.