Chapter 28 - Experimental Evidences for Parity Violating Energy Differences Between Enantiomers

Abstract

An important consequence of the unified theory of electromagnetic and weak interaction is the existence of a neutral current that generates parity-violating interactions between electrons and electrons and between electrons and neutrons. Experiments involving elementary particles and atoms confirm the theory ofelectroweak interaction. In enantiomeric molecules, the interaction induces a small difference between the energies of different enantiomers. The theory is extended to calculations of the parity-violating energy difference (PVED) between the L- and D-amino acids. The chapter explains the origin of the homochirality of biomolecules―the phenomenon that living systems contain nearly completely L-amino acids and D-sugars. Despite the smallness of PVED, there are the suggestions that PVED is the cause of the homochirality of biomolecules. Although the existence of a PVED between enantiomers is theoretically certain, its experimental confirmation is still missing.