On the Origin of the Violation of Hara's Theorem for Conserved Current

TL;DR

This paper discusses the reasons behind the violation of Hara's theorem in certain particle decays, emphasizing the role of current localization and challenging common assumptions in weak radiative hyperon decay models.

Contribution

It provides an argument that the violation of Hara's theorem is linked to the non-localization of the conserved current, and questions the applicability of vector meson dominance and quark-model assumptions.

Findings

Violation of Hara's theorem implies non-localized conserved current.

Measured asymmetry challenges the validity of Hara's theorem, vector meson dominance, or quark-model assumptions.

Theoretical analysis of weak radiative hyperon decays and their underlying assumptions.

Abstract

I elaborate on the argument that the violation of Hara's theorem for conserved current requires that the current is not sufficiently well localized. It is also stressed that whatever sign of asymmetry is measured in the $\Xi ^0 \to \Lambda \gamma $ decay, one of the following three statements must be incorrect: 1) Hara's theorem is satisfied, 2) vector meson dominance is applicable to weak radiative hyperon decays, and 3) basic structure of our quark-model description of nuclear parity-violation is correct.