Differential interaction of chiral β-particles with enantiomers

Abstract

VESTER¹ and Ulbricht² invoked the parity-violating weak interaction as the cause of biological homochirality. They postulated that a stereoselective synthesis or decay of chiral molecules could be induced by the left circularly polarized bremsstrahlung; this small effect would then be amplified to full homochirality^3–5. Despite much effort during the past thirty years, experimental results have been inconclusive and contradictory^6–12. The aim of the study described here was more modest; we did not want to demonstrate differential synthesis or the decay of enantiomers bombarded by β-particles. Rather, using pulse-height spectroscopy, we examined the Cerenkov radiation emitted as β-particles pass through liquid chiral enantiomers. Our results show that helical electrons do distinguish between molecules of opposite chirality, and complement results reported in earlier publications in which differential decay^6,13, positron annihilation^14,15, scattering^16,17 or other interactions^18–20 were observed.