Asymmetric Positron Annihilation in Chiral Tartrate and Tartaric Acid Crystals

Abstract

Positron annihilation lifetime spectroscopy (PALS) has been used to study the interactions of positrons with chiral tartaric acids and tartrates. Differences in lifetimes of and its intensity I2 were compared between large crystals grown from the D- and L- enantiomers of sodium ammonium tartrate and tartaric acid. A tentative but statistical difference in and I2 between enantiomers is noted with the L- enantiomers exhibiting longer positronium lifetimes and lower intensities, signifying a more stable environment for the positron and positronium. Possible implications for the dominance of L-amino acids in living matter are discussed.