Speaker
Description
The Accelerator Neutrino Neutron Interaction Experiment (ANNIE) is a 26-ton gadolinium-doped water Cherenkov detector operating on the Booster Neutrino Beam at Fermilab. The experiment's primary physics program is to measure the neutrino–nucleus interactions in water at the ~1 GeV energy scale, with a focus on neutrino-induced neutron production and interaction cross sections. Current analyses target neutron multiplicity in charged-current (CC) interactions together with measurements of CC and neutral-current (NC) cross sections, providing critical constraints on neutrino–nucleus interaction models and reducing systematic uncertainties in neutrino oscillation experiments. ANNIE also serves as a testbed for advanced detector technologies that enhance its physics capabilities. Large Area Picosecond Photodetectors (LAPPDs) provide sub-100 ps timing and high spatial resolution for light detection, and the experiment has achieved the first detection of muon neutrino interactions using LAPPDs, demonstrating their power for precision time-based event reconstruction. In addition, ANNIE has performed the first in-beam tests of Water-based Liquid Scintillator (WbLS), exploring hybrid Cherenkov–scintillation detection for next-generation neutrino detectors. This presentation will report updated CC and NC cross-section results and progress toward neutron multiplicity measurements. These results provide new data on neutrino–nucleus interactions in water and demonstrate the impact of precision timing and neutron tagging for future large-scale neutrino experiments.