[Paper Review] Masses by gauge flavor dynamics

P. Beneš, Jiří Hošek+1 more|arXiv (Cornell University)|Jan 18, 2011

Particle physics theoretical and experimental studies3 citations

TL;DR

This paper proposes a gauge-flavored dynamics model based on an asymptotically free SU(3)₆ gauge symmetry that spontaneously breaks to generate fermion masses and triggers electroweak symmetry breaking. With only one free parameter—the flavor coupling—the model uniquely predicts fermion mass ratios, sterile neutrinos, and pseudo-Nambu–Goldstone bosons, all viable dark matter candidates.

ABSTRACT

We gauge the experimentally observed flavor (family) index of chiral lepton and quark fields and argue that the resulting non-vectorial SU(3)_F dynamics completely self-breaks. This breakdown generates fermion masses, which in turn trigger electroweak symmetry breaking (EWSB). Suggested asymptotically free dynamics with an assumed non-perturbative infrared fixed point has just one free parameter and is therefore either right or plainly wrong. Weak point of field theories strongly coupled in the infrared, unfortunately, is that there is no reliable way of computing their spectrum. Because of its rigidity the model provides, however, rather firm theoretically safe experimental predictions without knowing the spectrum: First, anomaly freedom fixes the neutrino sector which contains almost sterile neutrino states. Second, global symmetries of the model, spontaneously broken by fermion masses imply the existence of a fixed pattern of (pseudo-)axions and (pseudo-)majorons. It is gratifying that the predicted both sterile neutrinos and the pseudo-Nambu--Goldstone bosons are the viable candidates for dark matter.

Motivation & Objective

• To explain fermion mass generation and electroweak symmetry breaking through a dynamical mechanism rooted in gauged flavor symmetry.
• To resolve the hierarchy problem by deriving the electroweak scale from top quark mass and critical scaling near an infrared fixed point.
• To ensure anomaly freedom and asymptotic freedom in a strongly coupled, non-abelian gauge theory with minimal new physics.
• To predict viable dark matter candidates—sterile neutrinos and pseudo-axions—through spontaneous global symmetry breaking.

Proposed method

• Gauge the flavor (family) index of chiral fermions to form an SU(3)₆ gauge symmetry with a single coupling constant h.
• Assume the SU(3)₆ dynamics is asymptotically free and self-breaks in the infrared, generating masses for the eight flavor-gluons.
• Use non-perturbative, large effective flavor charge exchanges between left- and right-handed fermions to dynamically generate fermion masses.
• Assign chiral fermions to fundamental or antifundamental representations of SU(3)₆ to break the symmetry and produce mass differences.
• Ensure anomaly cancellation by introducing right-handed neutrinos in specific SU(3)₆ representations, constrained by the condition η_AF < 9.
• Derive electroweak symmetry breaking as a consequence of fermion mass generation, linking the W and Z boson masses to fermion self-energies.

Experimental results

Research questions

• RQ1 Can electroweak symmetry breaking arise dynamically from the spontaneous breaking of a gauged flavor symmetry rather than from a fundamental Higgs scalar?
• RQ2 What is the minimal set of right-handed neutrinos required to cancel anomalies in a non-abelian SU(3)₆ flavor gauge theory with three families?
• RQ3 How can a single-parameter, asymptotically free gauge theory generate the observed fermion mass spectrum and electroweak scale?
• RQ4 What are the implications of global symmetry breaking due to fermion masses for the existence of pseudo-Nambu–Goldstone bosons and their role as dark matter?
• RQ5 Can sterile neutrinos and axion-like particles predicted by this model be viable dark matter candidates?

Key findings

• The model generates all fermion masses dynamically via non-perturbative flavor-gluon exchanges, with the top quark mass setting the electroweak scale.
• Anomaly freedom requires the addition of exactly 3 or 5 triplets of right-handed neutrinos, or equivalent combinations, to cancel the anomaly coefficient.
• The model predicts a finite number of anomaly-free and asymptotically free configurations, with η_AF < 9 constraining the number of new fermions.
• Spontaneous breaking of global symmetries from fermion masses leads to a fixed pattern of (pseudo-)axions and (pseudo-)majorons.
• Sterile neutrinos and pseudo-Nambu–Goldstone bosons are predicted as viable dark matter candidates, consistent with cosmological constraints.
• The model’s only free parameter, the flavor coupling h, uniquely determines all fermion mass ratios, making it falsifiable by precision mass measurements.