Comment on "Observability of the Neutrino Charge Radius"

TL;DR

This paper critically examines a previous claim that the neutrino charge radius is a gauge-independent physical observable, and demonstrates that it is generally gauge-dependent, challenging its physical observability.

Contribution

The paper refutes prior claims by showing that the neutrino charge radius is gauge-dependent, thus questioning its status as a physical observable.

Findings

Neutrino charge radius is gauge-dependent.

Previous claims of gauge independence are incorrect.

The NCR cannot be considered a physical observable.

Abstract

In Phys. Rev. Lett. 89, 101802 (2002); erratum, ibid. 89, 229902(E) (2002), Bernabeu, Papavassiliou, and Vidal claim that they can extract a gauge-independent neutrino charge radius (NCR) which is, therefore, a physical observable. We show here that this claim is incorrect by demonstrating that the NCR is, in general, gauge-dependent.