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Gauge Coupling Unification via A Novel Technicolor Model

Sven Bjarke Gudnason, Thomas A. Ryttov, Francesco Sannino

TL;DR

This work addresses gauge coupling unification without low-energy supersymmetry by replacing the SM Higgs sector with a technicolor dynamic, focusing on Minimal Walking Technicolor (MWT) and minimal fermion-content modifications. Using one-loop RG analysis, the authors demonstrate improved unification for MWT and related variants, compare them to the MSSM, and propose mechanisms to align the technicolor and SM couplings at a common high scale. A key result is that adjoint Weyl fermions and a bino-like state can raise the unification scale to $M_{GUT}\approx 2.65\times10^{15}$ GeV while keeping $B_{\rm theory}$ near the experimental target $B_{\rm exp}\approx0.72$, thereby mitigating proton decay constraints. They also present a simple GUT embedding and discuss dark matter candidates arising from the extended fermion sector, highlighting a rich phenomenology and a viable non-SUSY route to high-scale unification with testable predictions.

Abstract

We show that the recently proposed minimal walking technicolor theory together with a small modification of the Standard Model fermionic matter content leads to an excellent degree of unification of the gauge couplings. We compare the degree of unification with various time-honored technicolor models and the minimal supersymmetric extension of the Standard Model. We find that, at the one-loop level, the new theory provides a degree of unification higher than any of the other extensions above. The phenomenology of the present model is very rich with various potential dark matter candidates.

Gauge Coupling Unification via A Novel Technicolor Model

TL;DR

This work addresses gauge coupling unification without low-energy supersymmetry by replacing the SM Higgs sector with a technicolor dynamic, focusing on Minimal Walking Technicolor (MWT) and minimal fermion-content modifications. Using one-loop RG analysis, the authors demonstrate improved unification for MWT and related variants, compare them to the MSSM, and propose mechanisms to align the technicolor and SM couplings at a common high scale. A key result is that adjoint Weyl fermions and a bino-like state can raise the unification scale to GeV while keeping near the experimental target , thereby mitigating proton decay constraints. They also present a simple GUT embedding and discuss dark matter candidates arising from the extended fermion sector, highlighting a rich phenomenology and a viable non-SUSY route to high-scale unification with testable predictions.

Abstract

We show that the recently proposed minimal walking technicolor theory together with a small modification of the Standard Model fermionic matter content leads to an excellent degree of unification of the gauge couplings. We compare the degree of unification with various time-honored technicolor models and the minimal supersymmetric extension of the Standard Model. We find that, at the one-loop level, the new theory provides a degree of unification higher than any of the other extensions above. The phenomenology of the present model is very rich with various potential dark matter candidates.

Paper Structure

This paper contains 14 sections, 17 equations, 5 figures, 3 tables.

Table of Contents

  1. Introduction
  2. Notation and Conventions
  3. Studying SU(3)$\times$SU(2)$\times$U(1) Unification in Technicolor
  4. Minimal Walking Technicolor (MWT)
  5. Traditional Walking and Non-Walking One Family Model
  6. Partially Electroweak-Gauged Technicolor
  7. The Technicolor Coupling Constant
  8. Proton Decay
  9. Constructing a Simple Unifying Group
  10. Providing Mass to the fermions
  11. A New Extension of the Standard Model
  12. Unifying Technicolor as Well
  13. Comparing with the MSSM and Hint of Dark Matter
  14. Conclusions

Figures (5)

  • Figure 1: The running of the three standard model gauge couplings.
  • Figure 2: The running of the SM gauge couplings in the presence of adjoint technifermions (the technicolor coupling is not included here).
  • Figure 3: The running of the three SM gauge couplings in the new model with also adjoint fermionic matter for the SM gauge groups.
  • Figure 4: Left Panel: A zoom around the unification point of the running of the three SM gauge couplings in the new model with extra fermionic adjoint matter for the SM gauge groups. Right Panel: A zoom around the unification point for the couplings in the MSSM.
  • Figure 5: The running of the three SM gauge couplings as well as the technicolor one. MWT is made to unify with the other three couplings by enhancing the gauge group from ${SU(2)}$ of technicolor to ${SU(3)}$ while keeping the same fermionic matter content. We see that the scale where this enhancement of the gauge group should dynamically occur to obtain complete unification is around $10^8$ GeV.