Challenging Spontaneous Quantum Collapse with the XENONnT Dark Matter Detector

Aprile, E.; Aalbers, J.; Abe, K.; Ahmed Maouloud, S.; Althueser, L.; Andrieu, B.; Angelino, E.; Anton Martin, D.; Armbruster, S. R.; Arneodo, F.; Baudis, L.; Bazyk, M.; Bellagamba, L.; Biondi, R.; Bismark, A.; Boese, K.; Brown, A.; Bruno, G.; Budnik, R.; Cai, C.; Capelli, C.; Cardoso, J. M. R.; Cimental Chavez, A. P.; Colijn, A. P.; Conrad, J.; Cuenca-Garcia, J. J.; D'Andrea, V.; Daniel Garcia, L. C.; Decowski, M. P.; Deisting, A.; Di Donato, C.; Di Gangi, P.; Diglio, S.; Eitel, K.; El Morabit, S.; 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.; Giacomobono, R.; Girard, F.; Glade-Beucke, R.; Grandi, L.; Grigat, J.; Guan, H.; Guida, M.; Gyorgy, P.; Hammann, R.; Higuera, A.; Hils, C.; Hoetzsch, L.; Hood, N. F.; Iacovacci, M.; Itow, Y.; Jakob, J.; Joerg, F.; Kaminaga, Y.; Kara, M.; Kavrigin, P.; Kazama, S.; Kharbanda, P.; Kobayashi, M.; Koke, D.; Kopec, A.; Landsman, H.; Lang, R. F.; Levinson, L.; Li, I.; Li, S.; Liang, S.; Liang, Z.; Lin, Y. -T.; Lindemann, S.; Liu, K.; Liu, M.; Loizeau, J.; Lombardi, F.; Long, J.; Lopes, J. A. M.; Lucchetti, G. M.; Luce, T.; Ma, Y.; Macolino, C.; Mahlstedt, J.; Mancuso, A.; Manenti, L.; Marignetti, F.; Marrodan Undagoitia, T.; Martens, K.; Masbou, J.; Mastroianni, S.; Melchiorre, A.; Merz, J.; Messina, M.; Michael, A.; Miuchi, K.; Molinario, A.; Moriyama, S.; Mora, K.; Mosbacher, Y.; Murra, M.; Muller, J.; Ni, K.; Oberlack, U.; Paetsch, B.; Pan, Y.; Pellegrini, Q.; Peres, R.; Peters, C.; Pienaar, J.; Pierre, M.; Plante, G.; Pollmann, T. R.; Principe, L.; Qi, J.; Qin, J.; Ramirez Garcia, D.; Rajado, M.; Ravindran, A.; Razeto, A.; Redard-Jacot, L.; Singh, R.; Sanchez, L.; Dos Santos, J. M. F.; Sarnoff, I.; Sartorelli, G.; Schreiner, J.; Schulte, P.; Schulze Eissing, H.; Schumann, M.; Scotto Lavina, L.; Selvi, M.; Semeria, F.; Shagin, P.; Shi, S.; Shi, J.; Silva, M.; Simgen, H.; Stevens, A.; Szyszka, C.; Takeda, A.; Takeuchi, Y.; Tan, P. -L.; Thers, D.; Trinchero, G.; Tunnell, C. D.; Tonnies, F.; Valerius, K.; Vecchi, S.; Vetter, S.; Villazon Solar, F. I.; Volta, G.; Weinheimer, C.; Weiss, M.; Wenz, D.; Wittweg, C.; V. H. S., Wu; Xing, Y.; Xu, D.; Xu, Z.; Yamashita, M.; Yang, L.; Ye, J.; Yuan, L.; Zavattini, G.; Zhong, M.; Curceanu, C.; Manti, S.; Piscicchia, K.

doi:10.1103/2jm3-4976

We report on the search for x-ray radiation as predicted from dynamical quantum collapse with low-energy electronic recoil data in the energy range of 1-140 keV from the first science run of the XENONnT dark matter detector. Spontaneous radiation is an unavoidable effect of dynamical collapse models, which were introduced as a possible solution to the long-standing measurement problem in quantum mechanics. The analysis utilizes a model that for the first time accounts for cancellation effects in the emitted spectrum, which arise in the x-ray range due to the opposing electron-proton charges in xenon atoms. New world-leading limits on the free parameters of the Markovian continuous spontaneous localization and Diósi-Penrose models are set, improving previous best constraints by two orders of magnitude and a factor of five, respectively. For the strength and correlation length of the continuous spontaneous localization model, values in the originally proposed parameter ranges are experimentally excluded for the first time.