The T2K ND280 Off-Axis Pi-Zero Detector

Abstract The pi–zero detector (POD) is one of the subdetectors that makes up the off-axis near detector for the Tokai-to-Kamioka (T2K) long baseline neutrino experiment. The primary goal for the POD is to measure the relevant cross-sections for neutrino interactions that generate π 0 's, especially the cross-section for neutral current π 0 interactions, which are one of the dominant sources of background to the ν μ → ν e appearance signal in T2K. The POD is composed of layers of plastic scintillator alternating with water bags and brass sheets or lead sheets and is one of the first detectors to use Multi-Pixel Photon Counters (MPPCs) on a large scale.