Simulation of ρ^0 Meson Production in the Target of the NA64 Experiment

NA64 is an experiment to search for dark matter particles. Its main goal is to search for the so-called dark photon A^ a vector mediator between ordinary and dark matter. One of the possible channels for the production of A^ is the invisible decay of the ρ⁰ meson formed in the photoproduction process. The article presents a simulation of ρ⁰ meson production and provides an estimate of the number that could be obtained in the NA64 experiment. Possibility of searching for two modes of ρ⁰ meson decay for different tasks discussed.