Buckyballs release electron-positron pairs in forward directions

Commonly known as buckminsterfullerene, or 'buckyballs', C60 is stable, easily synthesised and sustainable at room temperatures. Thanks to these useful properties, Hervieux and Chakraborty's findings could have important implications for fields including astrophysics, materials physics, and pharmaceutical research. In particular, they could offer improvements in tests of how antimatter responds to gravity, which can involve structures including dipositronium and antihydrogen atoms; each of which feature positronium in the first steps of their fabrication processes.

When positrons of certain energies approach buckyballs at angles of up to 10 degrees, the physicists showed that a series of narrow, forward-facing positronium signals resulted from the 'diffraction resonance' of the particles. The effect is comparable to how light is diffracted by microscopic spherical obstructions; showing variation with larger fullerene molecules like C240, and when particles are excited to higher energy levels. Hervieux and Chakraborty modelled these properties through theoretical calculations of how diffraction resonance affected the angles over which positronium is emitted, as a function of positron impact energy. Their results offer important insights for the wide variety of researchers who use these short-lived structures. In future studies, the duo now hopes to further explore their potential for use in real experiments.