Speaker
Description
Cosmic-ray muons traversing liquid scintillator detectors produce spallation isotopes that constitute significant backgrounds in rare-event searches. Their production rate scales with target mass, and their spectral overlap complicates conventional background discrimination. Rather than treating these isotopes solely as a nuisance, we exploit them as an in-situ calibration resource. Many muon-induced spallation products exhibit characteristic $\beta$ and $\gamma$ decay features that provide persistent energy signatures throughout data taking. By combining reconstructed energy, decay time, spatial correlations with parent muons, and neutron production information, these events can be statistically isolated and used to constrain detector response. Using KamLAND-Zen, a leading $^{136}\text{Xe}$ neutrinoless double-beta decay experiment, I present a novel technique to constrain the detector energy scale through muon-induced spallation decays. This approach provides a complementary and continuous calibration method relevant for $0\nu\beta\beta$ and other rare-event searches in large liquid scintillator detectors.