Quantum Anomaly in Molecular Physics

TL;DR

This paper demonstrates that the interaction between an electron and a polar molecule exemplifies a quantum anomaly, revealing a critical dipole moment for electron capture, with implications for understanding quantum symmetry breaking.

Contribution

It introduces the concept of quantum anomaly in molecular physics through the electron-polar molecule interaction and analyzes symmetry breaking in different models.

Findings

Existence of a critical dipole moment for electron capture.

Confirmation of the phenomenon through experimental and numerical methods.

Analysis of symmetry breaking in point and finite dipole models.

Abstract

The interaction of an electron with a polar molecule is shown to be the simplest realization of a quantum anomaly in a physical system. The existence of a critical dipole moment for electron capture and formation of anions, which has been confirmed experimentally and numerically, is derived. This phenomenon is a manifestation of the anomaly associated with quantum symmetry breaking of the classical scale invariance exhibited by the point-dipole interaction. Finally, analysis of symmetry breaking for this system is implemented within two different models: point dipole subject to an anomaly and finite dipole subject to explicit symmetry breaking.