Quark mass hierarchy in 3-3-1 models

TL;DR

This paper analyzes the quark mass spectrum in a specific 3-3-1 gauge model, showing how the model naturally explains the hierarchy of quark masses through zero-texture matrices and mixing with heavy quarks.

Contribution

It introduces a particular 3-3-1 model with scalar triplets that produce a realistic quark mass hierarchy via zero-texture matrices and heavy quark mixing.

Findings

Predicts three massless quarks at the electroweak scale.

Generates small masses for u, d, s quarks through mixing with heavy quarks.

Achieves natural quark mass hierarchy consistent with observations.

Abstract

We study the mass spectrum of the quark sector in an special type I-like model with gauge symmetry $SU(3)_c \otimes SU(3)_L \otimes U(1)_X$. By considering couplings with scalar triplets at large ($\sim TeV$) and small ($\sim GeV$) scales, we obtain specific zero-texture mass matrices for the quarks which predict three massless quarks ($u,d,s$) and three massive quarks ($c,b,t$) at the electroweak scale ($\sim$ GeV). Taking into account mixing couplings with three heavy quarks at large scales predicted by the model, the three massless quarks obtain masses at small order that depends on the inverse of the large scale. Thus, masses of the form $m_u \lesssim m_d < m_s \sim MeV$ and $ m_{c,b,t} \sim GeV$ can be obtained naturally from the gauge structure of the model.