Characterization of the astrophysical diffuse neutrino flux using starting track events in IceCube

A measurement of the diffuse astrophysical neutrino spectrum is presented using IceCube data collected from 2011-2022 (10.3 years). We developed novel detection techniques to search for events with a contained vertex and exiting track induced by muon neutrinos undergoing a charged-current interactio...

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Bibliographic Details
Main Authors: Abbasi, R, Ackermann, M, Adams, J, Agarwalla, SK, Aguilar, JA, Ahlers, M, Alameddine, JM, Amin, NM, Andeen, K, Anton, G, Argüelles, C, Ashida, Y, Athanasiadou, S, Ausborm, L, Axani, SN, Bai, X, Balagopal, A, Baricevic, M, Barwick, SW, Bash, S, Basu, V, Bay, R, Beatty, JJ, Tjus, JB, Beise, J, Bellenghi, C, Benning, C, BenZvi, S, Berley, D, Bernardini, E, Besson, DZ, Blaufuss, E, Blot, S, Bontempo, F, Book, JY, Meneguolo, CB, Böser, S, Botner, O, Böttcher, J, Braun, J, Brinson, B, Brostean-Kaiser, J, Brusa, L, Burley, RT, Busse, RS, Butterfield, D, Campana, MA, Caracas, I, Carloni, K, Carpio, J, Sarkar, S, IceCube Collaboration
Format: Journal article
Language:English
Published: American Physical Society 2024
Description
Summary:A measurement of the diffuse astrophysical neutrino spectrum is presented using IceCube data collected from 2011-2022 (10.3 years). We developed novel detection techniques to search for events with a contained vertex and exiting track induced by muon neutrinos undergoing a charged-current interaction. Searching for these starting track events allows us to not only more effectively reject atmospheric muons but also atmospheric neutrino backgrounds in the southern sky, opening a new window to the sub-100 TeV astrophysical neutrino sky. The event selection is constructed using a dynamic starting track veto and machine learning algorithms. We use this data to measure the astrophysical diffuse flux as a single power law flux (SPL) with a best-fit spectral index of γ=2.58-0.09+0.10 and per-flavor normalization of φper-flavorAstro=1.68-0.22+0.19×10-18×GeV-1 cm-2 s-1 sr-1 (at 100 TeV). The sensitive energy range for this dataset is 3-550 TeV under the SPL assumption. This data was also used to measure the flux under a broken power law, however we did not find any evidence of a low energy cutoff.