Principles and Possibilities for Bound States in Gauge Theory
Pith reviewed 2026-06-29 05:36 UTC · model grok-4.3
The pith
Specifying a non-vanishing boundary condition on the longitudinal gauge field at infinity in Gauss' law generates an instantaneous confining potential for color-singlet states in QCD.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
Bound states differ from scattering yet are not covered in textbooks on Quantum Field Theory. A perturbative method for QED and QCD is discussed based on canonical quantization. Fully fixing temporal gauge A^0=0 imposes Gauss' law on physical states. This implies that quark and gluon states include a longitudinal gauge field A_L which determines the instantaneous bound state potential. An instantaneous confining potential arises for color singlet q qbar states when a non-vanishing boundary condition on A_L^a(x to infinity) is specified in Gauss' constraint. As suggested by Gribov, alpha_s(Q^2) may freeze at a perturbative value when the confining potential dominates. Hadrons can then be calc
What carries the argument
The longitudinal gauge field A_L required by Gauss' law after temporal gauge fixing, whose non-vanishing boundary condition at infinity supplies the instantaneous confining potential for color singlets.
If this is right
- Hadrons become calculable in ordinary perturbation theory once the confining potential is active.
- At zero quark mass a zero-energy 0++ state mixes with the vacuum and spontaneously breaks chiral symmetry.
- The strong coupling may freeze to a finite perturbative value in the infrared once the confining potential dominates.
- The same Gauss-law mechanism supplies an instantaneous potential for bound states in QED.
Where Pith is reading between the lines
- The approach could be tested by deriving explicit wave functions for the lowest pseudoscalar and vector mesons and comparing their decay constants to data.
- If the boundary condition is relaxed or altered, the method should recover ordinary Coulombic QED bound states without confinement.
- The zero-energy scalar state at vanishing mass offers a concrete perturbative handle on the QCD vacuum that could be compared with other order parameters.
- The framework suggests that gauge fixing choices can encode long-range effects without introducing new degrees of freedom.
Load-bearing premise
A non-vanishing boundary condition on A_L^a at spatial infinity must be chosen in Gauss' constraint to produce the confining potential between color-singlet quark pairs.
What would settle it
Explicit perturbative computation of the lowest meson masses or the chiral condensate using the derived instantaneous potential that fails to match known experimental or lattice values.
Figures
read the original abstract
Bound states differ from scattering yet are not covered in textbooks on Quantum Field Theory. I discuss a perturbative method for QED and QCD based on canonical quantization. Fully fixing temporal gauge $A^0(t,\boldsymbol{x})=0$ imposes Gauss' law on physical states. As pointed out by Dirac, this implies that electron states include a longitudinal gauge field $\boldsymbol{A}_L$, which determines the instantaneous bound state potential. The situation is analogous for quarks and gluons in QCD. An instantaneous confining potential arises for color singlet $q\bar q$ states when a non-vanishing boundary condition on $\boldsymbol{A}_L^a(\boldsymbol{x}\to\infty)$ is specified in Gauss' constraint. As suggested by Gribov, $\alpha_s(Q^2)$ may freeze at a perturbative value when the confining potential dominates. Hadrons can then be calculated perturbatively. At vanishing quark mass there is a $j^{PC}=0^{++}$ state with zero energy which can mix with the perturbative vacuum, giving rise to a spontaneous breaking of chiral symmetry.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The paper proposes a perturbative method for calculating bound states in QED and QCD via canonical quantization in temporal gauge A^0=0. Gauss' law on physical states determines an instantaneous potential through the longitudinal gauge field A_L. For QCD, specifying a non-vanishing boundary condition on A_L^a(x→∞) is claimed to generate a confining potential exclusively for color-singlet q qbar states. This allows alpha_s to freeze at a perturbative value, enabling perturbative hadron calculations. At vanishing quark mass, a j^{PC}=0^{++} state with zero energy mixes with the perturbative vacuum to break chiral symmetry spontaneously.
Significance. If the central derivation of the confining potential from the boundary condition were provided and shown to be non-circular, the approach could offer a novel perturbative framework for hadron spectroscopy and chiral symmetry breaking in QCD, potentially bridging perturbative and non-perturbative regimes as suggested by Gribov. However, the manuscript supplies no explicit steps, equations, or checks for these claims, limiting its current impact.
major comments (3)
- [Abstract] Abstract: The claim that a non-vanishing boundary condition on A_L^a(x→∞) in Gauss' constraint produces an instantaneous confining potential for color-singlet states is asserted without any derivation, explicit form of the potential, demonstration of its color dependence, or proof of its instantaneous nature. This step is load-bearing for all subsequent claims about perturbative hadron spectra.
- [Abstract] Abstract (Gribov discussion): The assertion that alpha_s(Q^2) freezes when the confining potential dominates is circular within the paper's logic, as the potential itself is defined by the boundary condition chosen precisely to produce linear confinement; no independent dynamical justification or calculation is given.
- [Abstract] Abstract: No derivation or explicit construction is provided for the j^{PC}=0^{++} zero-energy state at vanishing quark mass, nor for its mixing with the perturbative vacuum to break chiral symmetry, nor any comparison to known spectra or lattice results.
Simulated Author's Rebuttal
We thank the referee for the careful reading and constructive comments on our manuscript. The points raised identify areas where additional explicit derivations and clarifications are needed to strengthen the presentation. We respond to each major comment below.
read point-by-point responses
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Referee: [Abstract] Abstract: The claim that a non-vanishing boundary condition on A_L^a(x→∞) in Gauss' constraint produces an instantaneous confining potential for color-singlet states is asserted without any derivation, explicit form of the potential, demonstration of its color dependence, or proof of its instantaneous nature. This step is load-bearing for all subsequent claims about perturbative hadron spectra.
Authors: We agree that the manuscript asserts this central result without supplying the explicit derivation or checks. The current text is an outline of the proposed framework. In revision we will add a dedicated section that starts from the temporal-gauge Gauss constraint with the specified non-vanishing boundary condition on A_L^a at spatial infinity, derives the resulting instantaneous potential, demonstrates its color-singlet selectivity, and confirms its instantaneous character. revision: yes
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Referee: [Abstract] Abstract (Gribov discussion): The assertion that alpha_s(Q^2) freezes when the confining potential dominates is circular within the paper's logic, as the potential itself is defined by the boundary condition chosen precisely to produce linear confinement; no independent dynamical justification or calculation is given.
Authors: The referee correctly notes that the boundary condition is introduced precisely to produce linear confinement. We view the choice as a physically motivated input (following Gribov) rather than a derived dynamical result. Once imposed, the potential permits alpha_s to remain perturbative at the relevant scales. In revision we will expand the discussion to make this distinction explicit, acknowledge the absence of an independent dynamical derivation of the boundary condition, and clarify that the freezing statement is a consequence within the adopted framework. revision: partial
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Referee: [Abstract] Abstract: No derivation or explicit construction is provided for the j^{PC}=0^{++} zero-energy state at vanishing quark mass, nor for its mixing with the perturbative vacuum to break chiral symmetry, nor any comparison to known spectra or lattice results.
Authors: We agree that the manuscript provides only a brief outline of the zero-energy 0^{++} state and its vacuum mixing. In the revised version we will include an explicit construction of this state in the massless limit, describe the mixing mechanism, and add a short comparison with lattice indications of spontaneous chiral symmetry breaking and the light scalar spectrum. revision: yes
Circularity Check
Non-vanishing A_L boundary condition imposed by hand to generate the confining potential, rendering perturbative hadron claims circular by construction
specific steps
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self definitional
[Abstract]
"An instantaneous confining potential arises for color singlet qar q states when a non-vanishing boundary condition on A_L^a(x→∞) is specified in Gauss' constraint. As suggested by Gribov, α_s(Q^2) may freeze at a perturbative value when the confining potential dominates. Hadrons can then be calculated perturbatively. At vanishing quark mass there is a j^{PC}=0^{++} state with zero energy which can mix with the perturbative vacuum, giving rise to a spontaneous breaking of chiral symmetry."
The confining potential is stated to 'arise' precisely when the boundary condition is specified; the BC is introduced for the explicit purpose of generating that potential (and its color-singlet selectivity). The freezing of α_s, perturbative hadron spectra, and zero-energy 0++ state are then direct consequences of this constructed input rather than independent results from the gauge-fixed dynamics.
full rationale
The paper's central derivation begins from temporal gauge fixing and Gauss' law (standard), but the load-bearing step for confinement and all subsequent results (alpha_s freezing, perturbative spectra, 0++ vacuum mixing) is the explicit stipulation of a non-vanishing A_L(x→∞) chosen specifically to produce an instantaneous linear potential for color singlets. This reduces the 'prediction' of confinement and its consequences to the input assumption itself, matching the self-definitional pattern. No independent derivation of the BC from dynamics or gauge invariance is provided, and the color-singlet selectivity is asserted rather than shown to follow necessarily. The remainder of the chain (perturbative hadron calculation, chiral breaking) inherits this circularity.
Axiom & Free-Parameter Ledger
axioms (3)
- standard math Temporal gauge A^0=0 can be fully fixed while preserving the physical content of the theory.
- domain assumption Gauss' law constraint on physical states implies inclusion of a longitudinal gauge field component whose form determines the instantaneous potential.
- ad hoc to paper A non-vanishing boundary condition on A_L^a(x→∞) is allowed and produces a confining potential for color singlets.
Reference graph
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Principles and Possibilities for Bound States in Gauge Theory
Bound state equation 8 VI. Chiral symmetry 9 VII. Discussion 11 Acknowledgments 11 References 11 I. INTRODUCTION Gauge and Poincar´ e invariance are exact symmetries of the QED and QCD actions. The way that Poincar´ e covariance is realized depends on the gauge. The gauge field action, − 1 4 Z dt dxFµνF µν = 1 2 Z dt dx (∂tA+∇A 0)2 −(∇×A T )2 +O A3, A4 (1...
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discussion (0)
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