Observation of Seven Astrophysical Tau Neutrino Candidates with IceCube

• Published in: Physical review letters 2024-04, Vol.132 (15), p.151001-151001, Article 151001
• Main Authors: Abbasi, R, Ackermann, M, Adams, J, Agarwalla, S K, Aguilar, J A, Ahlers, M, Alameddine, J M, Amin, N M, Andeen, K, Anton, G, Argüelles, C, Ashida, Y, Athanasiadou, S, Axani, S N, Bai, X, Balagopal, V A, Baricevic, M, Barwick, S W, Basu, V, Bay, R, Beatty, J J, Becker Tjus, J, Beise, J, Bellenghi, C, Benning, C, BenZvi, S, Berley, D, Bernardini, E, Besson, D Z, Blaufuss, E, Blot, S, Bontempo, F, Book, J Y, Boscolo Meneguolo, C, Böser, S, Botner, O, Böttcher, J, Bourbeau, E, Braun, J, Brinson, B, Brostean-Kaiser, J, Burley, R T, Busse, R S, Butterfield, D, Campana, M A, Carloni, K, Carnie-Bronca, E G, Chattopadhyay, S, Chau, N, Chen, C, Chen, Z, Chirkin, D, Choi, S, Clark, B A, Classen, L, Coleman, A, Collin, G H, Connolly, A, Conrad, J M, Coppin, P, Correa, P, Cowen, D F, Dave, P, De Clercq, C, DeLaunay, J J, Delgado, D, Deng, S, Deoskar, K, Desai, A, Desiati, P, de Vries, K D, de Wasseige, G, DeYoung, T, Diaz, A, Díaz-Vélez, J C, Dittmer, M, Domi, A, Dujmovic, H, DuVernois, M A, Ehrhardt, T, Eller, P, Ellinger, E, El Mentawi, S, Elsässer, D, Engel, R, Erpenbeck, H, Evans, J, Evenson, P A, Fan, K L, Fang, K, Farrag, K, Fazely, A R, Feigl, N, Fiedlschuster, S, Fienberg, A T, Finley, C, Fischer, L, Fox, D, Franckowiak, A, Fritz, A
• Format: Article
• Language: English
• ISSN: 0031-9007; 1079-7114; 1079-7114
• DOI: 10.1103/PhysRevLett.132.151001

We report on a measurement of astrophysical tau neutrinos with 9.7 yr of IceCube data. Using convolutional neural networks trained on images derived from simulated events, seven candidate ν_{τ} events were found with visible energies ranging from roughly 20 TeV to 1 PeV and a median expected parent ν_{τ} energy of about 200 TeV. Considering backgrounds from astrophysical and atmospheric neutrinos, and muons from π^{±}/K^{±} decays in atmospheric air showers, we obtain a total estimated background of about 0.5 events, dominated by non-ν_{τ} astrophysical neutrinos. Thus, we rule out the absence of astrophysical ν_{τ} at the 5σ level. The measured astrophysical ν_{τ} flux is consistent with expectations based on previously published IceCube astrophysical neutrino flux measurements and neutrino oscillations.