Parity-Violating Energy Shifts of Murchison L-Amino Acids are Consistent with an Electroweak Origin of Meteorite L-Enantiomeric Excesses

In 1996, four α-methyl amino acids in the Murchison meteorite—L-isovaline, L-α-methylnorvaline, L-α-methyl-allo-isoleucine and L-α-methyl-isoleucine—were found to show significant enantiomeric excesses of the L form, ranging from 2% to 9%. Their deuterium to hydrogen isotope ratios suggest they formed in the pre-solar interstellar gas cloud rather than during a later aqueous processing phase on the asteroid parent body. In this paper we apply the techniques of the preceding two papers to compute the parity-violating energy shifts of these amino acids. We find that, in the gas phase, the PVESs of the neutral L forms of all four Murchison α-methyl amino acids are decisively negative, and there is even some correlation between the magnitudes of the L-excesses and the magnitudes of the PVESs—all of which is at least consistent with an electroweak origin of the Murchison enantiomeric excesses.