Reconstruction of low-momentum protons with the Fine-Grained Detector of the T2K experiment

Abstract

Low-momentum protons are important in the searches for neutrino interactions with correlated pairs of nucleons, 2p-2h. An attempt using the T2K 0ff-axis near detector data was made to use vertex activity (energy deposited near the vertex of the neutrino interaction) to search for a signature of such low-momentum particles. The analysis is based on extracting a signal of non-reconstructed particles expected to be associated to the vertex activity, which is later used by a neural network to detect the presence of the low-momentum proton in the interaction.