Using Machine Learning to Separate Cherenkov and Scintillation Light in Hybrid Neutrino Detector

Abstract

This research investigates the separation of Cherenkov and Scintillation light signals within a simulated Water-based Liquid Scintillator (WbLS) detector, utilizing the XGBoost machine learning algorithm. The simulation data were gathered using the Rat-Pac software, which was built on the Geant4 architecture. The use of the WbLS medium has the capability to generate both Scintillation and Cherenkov light inside a single detector. To show the separation power of these two physics events, we will use the supervised learning approach. The assessment utilized a confusion matrix, classification report, and ROC curve, with the ROC curve indicating a performance result of $0.96 \pm 1.2\times 10^{-4}$. The research also aimed to identify essential parameters for effectively distinguishing these physics events through machine learning. For this, the study also introduced the SHAP methodology, utilizing game theory to assess feature contributions. The findings demonstrated that the number of hits has a significant effect on the trained model, while the mean hit time has a somewhat smaller impact. This research advances the utilization of AI and simulation data for accurate Cherenkov and Scintillation light separation in neutrino detectors