Maximum likelihood reconstruction for the Daya Bay Experiment

The Daya Bay reactor neutrino experiment is designed to precisely determine the neutrino mixing angle θ₁₃. In this paper, we present an algorithm using the maximum likelihood (ML) method to reconstruct the vertex and energy of events in the anti-neutrino detector, based on a simplified optical model describing light propagation. The key parameters of the optical model are calibrated with ⁶⁰Co source, by comparing the predicted charges of the PMTs with the observed charges. With the optimized parameters, the ML reconstruction provides a uniform energy reconstruction, and a vertex reconstruction with small bias along radial direction