During the modern era of high precision neutrino physics measurements it has become increasingly important to deepen our understanding of detector performance. It is common for neutrino detector systems to be fully or partially composed of polystyrene-based scintillator bars, and most experiments now gather data for over a decade. Therefore it is crucial to investigate how the performance of such sensitive materials change with time. T2K (Tokai to Kamioka) is a long-baseline accelerator neutrino experiment located on the East coast of Japan. It has been collecting data since 2010 and will continue until the start of the next generation experiment Hyper-Kamiokande in 2027. Most of the subsystems of the T2K near detectors, ND280 and INGRID, will continue their operation as a part of the Hyper-Kamiokande experiment. The two near detectors are primarily composed of plastic scintillators of different shapes and origin. The data they have collected provides an opportunity to perform comprehensive studies of scintillator ageing. This talk will cover the light yield change study.
David Muñoz Pérez