Measurement of atmospheric neutrino mixing with improved IceCube DeepCore calibration and data processing
R. Abbasi, M. Ackermann, J. Adams, Sanjib Kumar Agarwalla, J. A. Aguilar, M. Ahlers, Jean-Marco Alameddine, N. M. Amin, K. Andeen, G. Anton, C. Argüelles, Yosuke Ashida, S. Athanasiadou, S. N. Axani, X. Bai, A. Balagopal V., M. Baricevic, S. W. Barwick, Vedant Basu, R. Bay, J. J. Beatty, K.-H. Becker, J. Becker Tjus, Jakob Beise, C. Bellenghi, Charlotte Benning, S. BenZvi, D. Berley, E. Bernardini, D. Z. Besson, G. Binder, E. Blaufuss, Summer Blot, F. Bontempo, J. Y. Book, Caterina Boscolo Meneguolo, S. Böser, O. Botner, J. Böttcher, E. Bourbeau, J. Braun, Bennett Brinson, J. Brostean-Kaiser, R. T. Burley, R. S. Busse, Delaney Butterfield, Michael Campana, K. Carloni, Erin Carnie-Bronca, Sharmistha Chattopadhyay, Thien Nhan Chau, C. Chen, Z. Chen, D. Chirkin, S. Choi, Brian Clark, Lew Classen, Alan Coleman, G. H. Collin, A. Connolly, J. M. Conrad, Paul Coppin, Pablo Correa, S. Countryman, D. F. Cowen, Pranav Dave, C. De Clercq, J. J. DeLaunay, D. Delgado, H.-P. Dembinski, Sen Deng, Kunal Deoskar, Abhishek Desai, P. Desiati, K. D. de Vries, G. de Wasseige, T. DeYoung, A. Diaz, J. C. Díaz–Vélez, Markus Dittmer, Alba Domi, H. Dujmovic, M. A. DuVernois, T. Ehrhardt, P. Eller, Sharif El Mentawi, R. Engel, H. Erpenbeck, John Evans, P. A. Evenson, Kwok Lung Fan, Ke Fang, Kareem Ramadan Farrag, A. R. Fazely, A. Fedynitch, Nora Feigl, S. Fiedlschuster, C. Finley, Leander Fischer, D. B. Fox
Abstract
We describe a new data sample of IceCube DeepCore and report on the latest measurement of atmospheric neutrino oscillations obtained with data recorded between 2011--2019. The sample includes significant improvements in data calibration, detector simulation, and data processing, and the analysis benefits from a sophisticated treatment of systematic uncertainties, with significantly greater level of detail since our last study. By measuring the relative fluxes of neutrino flavors as a function of their reconstructed energies and arrival directions we constrain the atmospheric neutrino mixing parameters to be ${\mathrm{sin}}^{2}{\ensuremath{\theta}}_{23}=0.51\ifmmode\pm\else\textpm\fi{}0.05$ and $\mathrm{\ensuremath{\Delta}}{m}_{32}^{2}=2.41\ifmmode\pm\else\textpm\fi{}0.07\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}\text{ }\text{ }{\mathrm{eV}}^{2}$, assuming a normal mass ordering. The errors include both statistical and systematic uncertainties. The resulting 40% reduction in the error of both parameters with respect to our previous result makes this the most precise measurement of oscillation parameters using atmospheric neutrinos. Our results are also compatible and complementary to those obtained using neutrino beams from accelerators, which are obtained at lower neutrino energies and are subject to different sources of uncertainties.