Excess electronic recoil events in XENON1T

Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Althueser, L.; Amaro, F.  D.; Antochi, V.  C.; Angelino, E.; Angevaare, J.  R.; Arneodo, F.; Barge, D.; Baudis, L.; Bauermeister, B.; Bellagamba, L.; Benabderrahmane, M.  L.; Berger, T.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Capelli, C.; Cardoso, J.  M.  R.; Cichon, D.; Cimmino, B.; Clark, M.; Coderre, D.; Colijn, A.  P.; Conrad, J.; Cussonneau, J.  P.; Decowski, M.  P.; Depoian, A.; Di Gangi, P.; Di Giovanni, A.; Di Stefano, R.; Diglio, S.; Elykov, A.; Eurin, G.; Ferella, A.  D.; Fulgione, W.; Gaemers, P.; Gaior, R.; Galloway, M.; Gao, F.; Grandi, L.; Hasterok, C.; Hils, C.; Hiraide, K.; Hoetzsch, L.; Howlett, J.; Iacovacci, M.; Itow, Y.; Joerg, F.; Kato, N.; Kazama, S.; Kobayashi, M.; Koltman, G.; Kopec, A.; Landsman, H.; Lang, R.  F.; Levinson, L.; Lin, Q.; Lindemann, S.; Lindner, M.; Lombardi, F.; Long, J.; Lopes, J.  A.  M.; López Fune, E.; Macolino, C.; Mahlstedt, J.; Mancuso, A.; Manenti, L.; Manfredini, A.; Marignetti, F.; Marrodán Undagoitia, T.; Martens, K.; Masbou, J.; Masson, D.; Mastroianni, S.; Messina, M.; Miuchi, K.; Mizukoshi, K.; Molinario, A.; Morå, K.; Moriyama, S.; Mosbacher, Y.; Murra, M.; Naganoma, J.; Ni, K.; Oberlack, U.; Odgers, K.; Palacio, J.; Pelssers, B.; Peres, R.; Pienaar, J.; Pizzella, V.; Plante, G.; Qin, J.; Qiu, H.; Ramírez García, D.; Reichard, S.; Rocchetti, A.; Rupp, N.; dos Santos, J.  M.  F.; Sartorelli, G.; Šarčević, N.; Scheibelhut, M.; Schreiner, J.; Schulte, D.; Schumann, M.; Scotto Lavina, L.; Selvi, M.; Semeria, F.; Shagin, P.; Shockley, E.; Silva, M.; Simgen, H.; Takeda, A.; Therreau, C.; Thers, D.; Toschi, F.; Trinchero, G.; Tunnell, C.; Vargas, M.; Volta, G.; Wang, H.; Wei, Y.; Weinheimer, C.; Weiss, M.; Wenz, D.; Wittweg, C.; Xu, Z.; Yamashita, M.; Ye, J.; Zavattini, G.; Zhang, Y.; Zhu, T.; Zopounidis, J.  P.; Mougeot, X.

doi:10.1103/PhysRevD.102.072004

We report results from searches for new physics with low-energy electronic recoil data recorded with theXENON1T detector. With an exposure of 0.65 tonne-years and an unprecedentedly low background rate of 762stat events=ðtonne × year × keVÞbetween 1 and 30 keV, the data enable one of the most sensitivesearches for solar axions, an enhanced neutrino magnetic moment using solar neutrinos, and bosonic darkmatter. An excess over known backgrounds is observed at low energies and most prominent between 2 and3 keV. The solar axion model has a3.4σsignificance, and a three-dimensional 90% confidence surface isreported for axion couplings to electrons, photons, and nucleons. This surface is inscribed in the cuboiddefined bygae<3.8×10−12,gaegeffan<4.8×10−18, andgaegaγ<7.7×10−22GeV−1, and excludes eithergae¼0orgaegaγ¼gaegeffan¼0. The neutrino magnetic moment signal is similarly favored over backgroundat3.2σ, and a confidence interval ofμν∈ð1.4;2.9Þ×10−11μB(90% C.L.) is reported. Both results are instrong tension with stellar constraints. The excess can also be explained byβdecays of tritium at3.2σsignificance with a corresponding tritium concentration in xenon ofð6.22.0Þ×10−25mol=mol. Such atrace amount can neither be confirmed nor excluded with current knowledge of its production and reductionmechanisms. The significances of the solar axion and neutrino magnetic moment hypotheses are decreasedto2.0σand0.9σ, respectively, if an unconstrained tritium component is included in the fitting. With respectto bosonic dark matter, the excess favors a monoenergetic peak atð2.30.2ÞkeV (68% C.L.) with a3.0σglobal (4.0σlocal) significance over background. This analysis sets the most restrictive direct constraints todate on pseudoscalar and vector bosonic dark matter for most masses between 1 and 2 10keV=c2. We alsoconsider the possibility that37Ar may be present in the detector, yielding a 2.82 keV peak from electroncapture. Contrary to tritium, the37Ar concentration can be tightly constrained and is found to be negligible

Excess electronic recoil events in XENON1T / Aprile, E.; Aalbers, J.; Agostini, F.; Alfonsi, M.; Althueser, L.; Amaro, F. D.; Antochi, V. C.; Angelino, E.; Angevaare, J. R.; Arneodo, F.; Barge, D.; Baudis, L.; Bauermeister, B.; Bellagamba, L.; Benabderrahmane, M. L.; Berger, T.; Brown, A.; Brown, E.; Bruenner, S.; Bruno, G.; Budnik, R.; Capelli, C.; Cardoso, J. M. R.; Cichon, D.; Cimmino, B.; Clark, M.; Coderre, D.; Colijn, A. P.; Conrad, J.; Cussonneau, J. P.; Decowski, M. P.; Depoian, A.; Di Gangi, P.; Di Giovanni, A.; Di Stefano, R.; Diglio, S.; Elykov, A.; Eurin, G.; Ferella, A. D.; Fulgione, W.; Gaemers, P.; Gaior, R.; Galloway, M.; Gao, F.; Grandi, L.; Hasterok, C.; Hils, C.; Hiraide, K.; Hoetzsch, L.; Howlett, J.; Iacovacci, M.; Itow, Y.; Joerg, F.; Kato, N.; Kazama, S.; Kobayashi, M.; Koltman, G.; Kopec, A.; Landsman, H.; Lang, R. F.; Levinson, L.; Lin, Q.; Lindemann, S.; Lindner, M.; Lombardi, F.; Long, J.; Lopes, J. A. M.; López Fune, E.; Macolino, C.; Mahlstedt, J.; Mancuso, A.; Manenti, L.; Manfredini, A.; Marignetti, F.; Marrodán Undagoitia, T.; Martens, K.; Masbou, J.; Masson, D.; Mastroianni, S.; Messina, M.; Miuchi, K.; Mizukoshi, K.; Molinario, A.; Morå, K.; Moriyama, S.; Mosbacher, Y.; Murra, M.; Naganoma, J.; Ni, K.; Oberlack, U.; Odgers, K.; Palacio, J.; Pelssers, B.; Peres, R.; Pienaar, J.; Pizzella, V.; Plante, G.; Qin, J.; Qiu, H.; Ramírez García, D.; Reichard, S.; Rocchetti, A.; Rupp, N.; dos Santos, J. M. F.; Sartorelli, G.; Šarčević, N.; Scheibelhut, M.; Schreiner, J.; Schulte, D.; Schumann, M.; Scotto Lavina, L.; Selvi, M.; Semeria, F.; Shagin, P.; Shockley, E.; Silva, M.; Simgen, H.; Takeda, A.; Therreau, C.; Thers, D.; Toschi, F.; Trinchero, G.; Tunnell, C.; Vargas, M.; Volta, G.; Wang, H.; Wei, Y.; Weinheimer, C.; Weiss, M.; Wenz, D.; Wittweg, C.; Xu, Z.; Yamashita, M.; Ye, J.; Zavattini, G.; Zhang, Y.; Zhu, T.; Zopounidis, J. P.; Mougeot, X.. - In: PHYSICAL REVIEW D. - ISSN 2470-0010. - 102:7(2020), p. 072004. [10.1103/PhysRevD.102.072004]