3D topological reconstruction in liquid scintillator detectors

The precise reconstruction of charged particle tracks in unsegmented liquid scintillator (LSc) neutrino detectors, e.g., from muons, is an important prerequisite for the efficient rejection of cosmogenic background events or the analysis of multi-GeV neutrino interactions. Topological information on such events, i.e., the reconstructed 3D density distribution of isotropically emitted scintillation photons, opens up new ways to accomplish these tasks. Especially future multi-kiloton LSc detectors will profit from improved (muon) track reconstruction possibilities.

Furthermore, the method presented here can also give valuable information on events traditionally treated as point-like (MeV). This offers the potential for particle discrimination at energies relevant for solar- or reactor-neutrino programs. We show that using this methods it is possible to distinguish between electrons and gammas at 2 MeV visible energy with an acceptance of 90%. Cherenkov-light presents a challenge, but also an opportunity in this context. Its potential to deliver directional information highly depends on the relative ratio between the scintillation- and Cherenkov-photons detected. However, an integrated analysis over many events could even be possible in high light yield liquid scintillator.