First-principle Event Reconstruction by Time-Charge Readouts for the Taishan Antineutrino Observatory

The Taishan Antineutrino Observatory (TAO) is a liquid-scintillator satelliteexperiment of the Jiangmen Underground Neutrino Observatory (JUNO) to measurethe reference reactor neutrino spectrum with sub-percent energy resolution. Weuse inhomogeous Poisson process and Tweedie generalized linear model (GLM) tocalibrate the detector response and the charge distribution of a SiPM. Wedevelop a pure probabilistic method using time and charge of SiPMs from firstprinciples to reconstruct point-like events in the TAO central detector. Thanksto our precise model and the high photo-coverage and quantum efficiency of theSiPM tiles at TAO, we achieve a vertex position resolution better than 16 mmand an energy resolution of about 2performance of liquid scintillator detectors. Our methodology is applicable toother experiments that utilize PMTs for time and charge readouts.