Quark and lepton masses from top loops

TL;DR

This paper proposes a model where all fermion masses, except the top, are generated through loop processes involving the top quark, explaining the mass hierarchy without requiring generational symmetries.

Contribution

The authors construct a renormalizable model that generates realistic fermion mass patterns through loop effects, without needing symmetry-based differentiation of generations.

Findings

Fermion masses arise from loop processes involving the top quark.

The model predicts specific loop orders for different fermion masses.

Potential observable effects in future experiments are identified.

Abstract

Assuming that the leptons and quarks other than top are massless at tree level, we show that their masses may be induced by loops involving the top quark. As a result, the generic features of the fermion mass spectrum arise from combinations of loop factors. Explicitly, we construct a renormalizable model involving a few new particles, which leads to 1-loop bottom and tau masses, a 2-loop charm mass, 3-loop muon and strange masses, and 4-loop masses for first generation fermions. This realistic pattern of masses does not require any symmetry to differentiate the three generations of fermions. The new particles may produce observable effects in future experiments searching for mu to e conversion in nuclei, rare meson decays, and other processes.