Absence of Chiral Fermions in the Eichten--Preskill Model

TL;DR

The paper demonstrates that the Eichten--Preskill model cannot produce chiral fermions due to spontaneous symmetry breaking and Dirac-like fermions, challenging its original purpose.

Contribution

It provides a critical analysis showing the Eichten--Preskill model does not yield chiral fermions, contrary to initial expectations.

Findings

Spontaneous symmetry breaking occurs in the model.

Fermions are Dirac-like across the phase diagram.

Related Higgs-Yukawa models also fail to produce chiral fermions.

Abstract

The model proposed by Eichten and Preskill for obtaining theories with chiral fermions from the lattice is shown to undergo spontaneous symmetry breaking. In addition, the fermions appear to be Dirac-like everywhere in the phase diagram with no room for undoubled Weyl fermions. The phase diagram of a closely related Higgs-Yukawa model is similar to that of the Smit--Swift model, which also does not give rise to chiral fermions. These results cast serious doubts on the original scenario for the emergence of chiral fermions.