Weak Neutral Current Interactions with Alpha-Methyl Amino Acids as a Mechanism for Prebiotic Chiral Symmetry Breaking: A Theoretical Framework and Experimental Proposal

The origin of biological homochirality — the near-universal preference for L-amino acids and D- sugars in living systems — remains one of the most consequential unsolved problems in the chem- istry of life’s origins. Existing hypotheses, including asymmetric photolysis by circularly polarised light and spontaneous ampli1cation via autocatalytic processes, fail to provide a satisfactory ac- count of either the initial symmetry-breaking event or its apparent universality. Here we propose a novel mechanistic framework in which weak neutral current (WNC) interactions between left- handed neutrinos and alpha-methyl amino acid precursors generate a small but consistent L- enantiomeric excess in the prebiotic environment. This initial excess — potentially as small as 0.01% — is then ampli1ed to functional homochirality via well-characterised autocatalytic pro- cesses analogous to the Soai reaction. The proposed mechanism is consistent with the observed L- excess in alpha-methyl amino acids in carbonaceous chondrites, provides a natural account of the universality of biological chirality, and generates speci1c, falsi1able experimental predictions. We outline a two-stage experimental programme for testing the central prediction, including a near- term proposal utilising existing reactor neutrino infrastructure. Parity-violating energy diIerence (PVED) calculations for the speci1c molecular candidates identi1ed here are deferred to future computational work and represent a critical next step in validating this framework.

Keywords: Homochirality, Weak Neutral Current, Alpha-Methyl Amino Acids, Parity Violation, Prebiotic Chemistry, Soai Reaction, Abiogenesis, Neutrino Flux, Chiral Symmetry Breaking