A Toy Model for Chiral Symmetry Breaking via V(Φ, θ) in Motion Theory
To make the emergence of chiral gauge symmetries (such as SU(2)L for weak interactions) more concrete within Motion Theory, we explore a simplified "toy model" for the potential $V(\Phi, \theta)$. This model aims to demonstrate how Spontaneous Symmetry Breaking (SSB) can occur, driven by the vacuum expectation values (VEVs) of scalar degrees of freedom derived from the fundamental $\Phi_{\mu\nu}$ field and the non-commutativity/torsion field $\theta_{\mu\nu}(x)$. The model will also incorporate Z₃; symmetry, linking it to potential topological structures like Z₃;-Glueballs.
1. Scalar Fields for Symmetry Breaking
To simplify the analysis, we consider effective scalar fields whose VEVs drive the symmetry breaking, rather than the full tensor structure of $\Phi_{\mu\nu}$ and $\theta_{\mu\nu}$.
- Chiral Symmetry Breaking Field ($\phi$): Let $\phi$ be a complex scalar field (or a set of scalar fields) representing the degrees of freedom from $\Phi_{\mu\nu}$ primarily responsible for breaking a larger chiral symmetry (e.g., SU(2)L x SU(2)R). The VEV of $\phi$ will be the primary order parameter for this breaking.
- Z₃; Symmetry and θ-related Field ($\chi$): Let $\chi$ be another complex scalar field related to the dynamics of $\theta_{\mu\nu}$ or its scalar invariants. This field is explicitly assumed to carry Z₃; symmetry, transforming as $\chi \rightarrow e^{i2\pi n/3} \chi$. Its VEV, $\langle\chi\rangle$, will determine if Z₃; symmetry is spontaneously broken and can influence the pattern of chiral symmetry breaking.
2. Proposed Potential $V(\phi, \chi)$
A general potential combining these fields can be written as $V(\phi, \chi) = V_\phi(\phi) + V_\chi(\chi) + V_{int}(\phi, \chi)$.
2.1. Potential for Chiral Symmetry Breaking ($V_\phi(\phi)$)
A standard "Mexican hat" potential can be used for $\phi$ to induce SSB of the larger chiral group:
If $\mu_\phi^2 > 0$, $\phi$ acquires a non-zero VEV: $\langle |\phi| \rangle = v_\phi = \sqrt{\frac{\mu_\phi^2}{2\lambda_\phi}}$.
2.2. Potential for Z₃; Symmetry ($V_\chi(\chi)$)
To incorporate Z₃; symmetry for the $\chi$ field, and allow for its SSB:
The $\delta_\chi (\chi^3 + (\chi^*)^3)$ term explicitly respects Z₃; symmetry. If $\mu_\chi^2 > 0$ and $\delta_\chi \neq 0$, this potential can lead to three distinct degenerate minima for $\chi$, breaking Z₃; symmetry spontaneously. The phase of $\langle\chi\rangle$ would settle into one of three preferred directions (e.g., $0, 2\pi/3, 4\pi/3$).
2.3. Interaction Term ($V_{int}(\phi, \chi)$)
A simple coupling term between $\phi$ and $\chi$ allows their VEVs to influence each other:
The full potential is the sum of these terms. The effective mass-squared term for $\chi$ would be $(-\mu_\chi^2 + \lambda_{\phi\chi} v_\phi^2)$.
3. Vacuum Expectation Values (VEVs) and Symmetry Breaking Pattern
The true vacuum of the theory is found by minimizing the total potential $V(\phi, \chi)$.
- The VEV $\langle\phi\rangle = v_\phi \neq 0$ breaks the initial chiral symmetry (e.g., SU(2)L x SU(2)R). The remaining symmetry (e.g., SU(2)L or SU(2)L x U(1)Y) depends on the specific representation and transformation properties of $\phi$ under the initial group.
- The VEV $\langle\chi\rangle = v_\chi e^{i\alpha_\chi} \neq 0$ (where $\alpha_\chi$ takes one of three values) spontaneously breaks the Z₃; symmetry (or a U(1) down to Z₃; if $\delta_\chi$ term is dominant over a U(1) symmetric part).
The interplay between $v_\phi$ and $v_\chi$ through $\lambda_{\phi\chi}$ can lead to a rich vacuum structure and pattern of symmetry breaking.
4. Conceptual Mass Generation for Gauge Bosons and Fermions
- Gauge Boson Masses: When the chiral symmetry is broken by $\langle\phi\rangle \neq 0$, some gauge bosons associated with the broken generators acquire mass through the standard Higgs mechanism (i.e., via terms like $(D_\mu \langle\phi\rangle)^\dagger (D^\mu \langle\phi\rangle)$). For example, if SU(2)L x SU(2)R breaks to SU(2)L, the SU(2)R gauge bosons become massive.
- Fermion Masses and Chirality via $\langle\theta\rangle$:
In our torsion-based approach, fermion dynamics are modified by $\theta_{\mu\nu}$. If
the VEV
$\langle\chi\rangle$ is related to (or induces) a non-zero VEV for relevant components
of the
$\theta_{\mu\nu}$ field, i.e., $\langle\theta_{\mu\nu}\rangle \neq 0$, this constant
background
$\langle\theta_{\mu\nu}\rangle$ affects fermions.
- As discussed previously, scalar invariants of $\langle\theta_{\mu\nu}\rangle$ (like $\langle\theta_{\alpha\beta}\rangle\langle\theta^{\alpha\beta}\rangle$) can lead to effective mass terms ($\delta m \bar{\psi}\psi$) or pseudo-scalar mass terms ($\delta m_5 \bar{\psi}i\gamma_5\psi$). These explicitly mix left- and right-handed fermions.
- The VEV $\langle\theta_{\mu\nu}\rangle$ itself might possess a chiral structure or induce chiral-specific couplings in the modified Dirac equation's interaction terms. This could be a source for the observed chiral nature of weak interactions, effectively making the "torsional background" experienced by fermions chiral.
5. Topological Defects and Relation to TeV-Scale Resonances
- Z₃; Symmetry Breaking and Defects: The SSB of Z₃; symmetry by $\langle\chi\rangle \neq 0$ can lead to the formation of Z₃; domain walls (if $\chi$ settles into different Z₃; vacua in different regions of space) or Z₃; cosmic strings (if Z₃; is a remnant of a broken continuous symmetry).
- Masses of Defects (1.52 TeV, 1.71 TeV): The energy scale of these defects, and thus the potential masses of localized topological structures like Z₃;-Glueballs, would be determined by the VEVs $v_\phi$, $v_\chi$ and the parameters in $V(\phi, \chi)$ (e.g., $\mu_\chi, \lambda_\chi, \delta_\chi$). The observed 1.52 TeV and 1.71 TeV resonances could be interpreted as such Z₃;-Glueballs, implying that the relevant symmetry breaking scale is in the TeV range.
This toy model, while simplified, provides a conceptual framework for understanding how a potential $V(\Phi, \theta)$ within Motion Theory can achieve spontaneous breaking of both a larger chiral symmetry (leading to chiral gauge interactions like SU(2)L) and Z₃; symmetry. The VEV of the $\theta$-related field $\chi$ can influence fermion masses/chirality via torsion-mediated interactions and set the mass scale for topological Z₃;-Glueball candidates.