Hadron Production Measurements for Long-Baseline Neutrino Experiments with NA61/SHINE

A precise prediction of the neutrino flux is a key ingredient for achieving the physics goals of long-baseline neutrino experiments. In modern accelerator-based neutrino experiments, neutrino beams are created from the decays of secondary hadrons produced in hadron-nucleus interactions. Hadron production is the leading systematic uncertainty source on the neutrino flux prediction; therefore, its precise measurement is essential. The NA61/SHINE is a fixed-target experiment at the CERN Super Proton Synchrotron, which studies hadron production in hadron-nucleus and nucleus-nucleus collisions for various physics goals. For neutrino physics, light hadron beams (protons, pions, and kaons) are collided with a light nuclear target (carbon, aluminum, and beryllium) and spectra of outgoing hadrons are measured. These proceedings will review the recent results and ongoing hadron production measurements with NA61/SHINE for the precise neutrino flux predictions in the T2K and Fermilab long-baseline neutrino experiments. It will also discuss the prospects for future hadron production measurements with NA61/SHINE beyond 2020, after the Long Shutdown 2 of the accelerator complex at CERN.