Nucleon Decay and Neutrino Experiments

The observation of electron-neutrino appearance by T2K paves the way to determine the massordering and to explore CPV in the lepton sector, which may hold a critical key to our understandingof the matter-antimatter asymmetry in the universe. In the Nature paper (Cover story, April 16,2020 issue) T2K showed an initial hint of CPV. We contributed significantly to this result throughimproved event reconstruction and analysis optimization. This result makes the prospects of T2Kestablishing 3 sigma evidence and DUNE establishing 5 sigma discovery for CPV in neutrinos verybright. We led a US-Japan program to construct a SuperFGD/3DST prototype. We played a leadingrole in taking neutron beam data at LANL, and publishing a paper on neutron cross-section on CH.We led the SuperFGD US group to construct, install, and commission the SuperFGD detector. Thedetector has been installed in the T2K ND280 magnet, and it is currently taking beam data andrecording neutrino interaction events. We are looking forward to doing exciting physics with thesenew data. In addition, we contributed significantly to the Super-Kamiokande/T2K and NOvA/T2Kjoint fits. The results from these joint fits have been released to the public recently. In DUNE, we played a leading role in shaping the Near Detector (ND) design and establishedDUNE-PRISM as part of the ND. We played key roles in ProtoDUNE by participating in detectorconstruction (FC), installation and commissioning, and in prototyping of the photon detectionsystem (PDS) for the Far Detector 2 (FD2). We have been contributing to the FD cold electronicstesting at BNL and we are engaged in designing a combined system of FC and PDS for the FD3. For the next two years, we propose to carry out a well balanced research program in T2K andDUNE. We propose to continue our current involvement in T2K which will provide invaluable datafor a rich physics program that is essential for graduate students, and postdocs. With the upgradedND280, we have a variety of new software and physics analysis projects. We propose to contributeto: ProtoDUNE II (vertical drift); the FD cold electronics testing and installation; FD2 PDS; FD3combined FC and PDS system (APEX); and preparation of the DUNE oscillation analysis. Finally, we have been gradually employing AI/ML tools in our research. In particular, we are developing novel uses of AI/ML for event reconstruction to implement hyper-informative likelihoods.  We plan to extend this capability to take advantage of rapid advances in AI/ML technology. List of Collaborative Experiments:1) DUNE Experiment2) T2K Experiment