A cornucopia of antineutrons and hyperons from super J/psi factory for next-generation nuclear and particle physics high-precision experiments

In order to study the interactions and structure of various types of matter one typically needs to carry out scattering experiments utilizing many different particles as projectiles. Whereas beams of $e^\pm$, $\mu^\pm$, $\pi^\pm$, $K^\pm$, proton, antiproton, and of various heavy ions have been produced and have enabled many scientific breakthroughs, beams of antineutrons, hyperons ($\Lambda$, $\Sigma$ and $\Xi$) and their antiparticles are typically not easy to obtain. Here we point out and investigate a new high-quality source of these particles: a super $J/\psi$ factory with capability of accumulating trillions of $J/\psi$ decays each year. In the relevant $J/\psi$ decays the desired particle is produced together with other final state particles that can be tagged. This allows accurate determination of the flux and momentum of the projectile, enabling unprecedented precision-study of the corresponding interactions with a broad range of targets. These novel high-statistics sources of baryons and antibaryons with precisely known kinematics open fresh opportunities for applications in particle and nuclear physics, including antinucleon-nucleon interaction, nonvalence $s\bar{s}$ component of the nucleon, (anti)hyperon-nucleon interaction, OZI violation, (multi-strange) hypernuclei, exotic light hadron spectroscopy and many others, as well as calibration of Monte Carlo simulation for hadronic and medical physics.