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arxiv: 2605.09000 · v1 · submitted 2026-05-09 · ✦ hep-ph

Recognition: 2 theorem links

· Lean Theorem

Optimizing Yukawa couplings to suppress Dimension-five Proton Decay in SU(5) GUT

Junpei Ikemoto, Naoyuki Haba, Toshifumi Yamada, Yasuhiro Shimizu

Authors on Pith no claims yet

Pith reviewed 2026-05-12 01:47 UTC · model grok-4.3

classification ✦ hep-ph
keywords SU(5) GUTproton decayYukawa couplingsmachine learning optimizationsupersymmetric GUTdimension-five operatorsAdam optimizertan beta
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The pith

Optimizing Yukawa couplings via Adam allows supersymmetric SU(5) models to evade current proton decay limits.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

This paper demonstrates that machine learning can navigate the complex 33-dimensional space of Yukawa couplings in an extended supersymmetric SU(5) grand unified theory to suppress dimension-five proton decay. The authors define a loss function based on the decay width for p to K+ anti-nu and use the Adam optimizer to find viable points. They show that for a range of tan beta values, the resulting proton lifetime exceeds the experimental lower bound of 5.9 times 10 to the 33 years. This matters because the minimal SUSY SU(5) model has long been threatened by too-fast proton decay, and this technique offers a systematic way to identify safe parameter regions without exhaustive scanning.

Core claim

In the supersymmetric SU(5) GUT extended by 45 and anti-45 Higgs representations, the dimension-five proton decay operators can be suppressed by suitable choices of Yukawa couplings. By employing the Adam optimizer to minimize the partial width of p to K+ anti-nu in the 33-dimensional parameter space, regions are identified where the proton lifetime surpasses the Super-Kamiokande bound for multiple values of tan beta.

What carries the argument

Adam optimizer minimizing a loss function based on the p to K+ anti-nu decay width over the 33 Yukawa coupling parameters.

If this is right

  • The optimized Yukawa couplings suppress the dominant proton decay mode below experimental limits.
  • Varying tan beta does not prevent finding viable points that satisfy the lifetime bound.
  • The approach bypasses the computational intractability of brute-force scans in high-dimensional spaces.
  • Such models can remain consistent with proton decay constraints while retaining GUT unification features.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Similar optimization could identify viable regions in other GUT models facing proton decay issues.
  • The chosen Yukawa values might simultaneously help satisfy fermion mass or neutrino constraints without additional tuning.
  • Future higher-sensitivity proton decay experiments could directly test the specific optimized parameter regions.
  • Applying the method to different GUT gauge groups might show which extensions most easily suppress dangerous operators.

Load-bearing premise

The Adam optimizer reliably locates sufficiently good minima in the 33-dimensional Yukawa space that suppress proton decay rates.

What would settle it

An independent calculation at the reported optimized Yukawa points showing a proton lifetime below 5.9 x 10^33 years, or the optimizer failing to reach low decay rates from varied initial conditions.

Figures

Figures reproduced from arXiv: 2605.09000 by Junpei Ikemoto, Naoyuki Haba, Toshifumi Yamada, Yasuhiro Shimizu.

Figure 1
Figure 1. Figure 1: Optimization results for the proton decay suppression for tan [PITH_FULL_IMAGE:figures/full_fig_p013_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: Distributions of the N = 4096 optimized parameters for tan β = 3 (40 bins each). (a) The 9 mixing angles (ϕi , θi , δ, χi) for the unitary matrix Uu. (b) The 9 mixing angles for the unitary matrix Ue. 14 [PITH_FULL_IMAGE:figures/full_fig_p014_2.png] view at source ↗
Figure 2
Figure 2. Figure 2: (Continued) (c) The 9 mixing angles for the unitary matrix [PITH_FULL_IMAGE:figures/full_fig_p015_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: Comparison of the initial and optimized proton lifetime distributions for tan [PITH_FULL_IMAGE:figures/full_fig_p017_3.png] view at source ↗
read the original abstract

The minimal supersymmetric $SU(5)$ grand unified theory (GUT) provides a highly compelling framework for physics beyond the Standard Model (SM). However, it suffers from a severe phenomenological challenge: rapid proton decay mediated by colored-Higgsino exchange via dimension-five operators. Resolving this issue often requires adjustments to the Yukawa couplings and the potential sectors, generating a vast and complex parameter space where traditional brute-force numerical scans are rendered computationally intractable due to the curse of dimensionality. In this paper, we overcome this limitation by applying machine learning optimization techniques. We investigate a supersymmetric $SU(5)$ model extended with $\mathbf{45}$ and $\overline{\mathbf{45}}$ Higgs representations, defining a loss function based on the partial decay width of $p \to K^+ \bar{\nu}$. Utilizing the Adam optimizer, we systematically explore the 33-dimensional parameter space to identify regions that suppress proton decay. Furthermore, we vary $\tan \beta$ to thoroughly investigate whether the optimized proton lifetime can consistently exceed the stringent experimental lower bound of $5.9 \times 10^{33}$ years established by the Super-Kamiokande collaboration.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

2 major / 1 minor

Summary. The manuscript applies the Adam optimizer to explore the 33-dimensional space of Yukawa couplings (plus tan β) in a supersymmetric SU(5) GUT extended by 45 and 45-bar Higgs representations. A loss function based on the partial width of p → K⁺ ν-bar is minimized with the goal of driving the proton lifetime above the Super-Kamiokande bound of 5.9 × 10³³ yr.

Significance. If the reported points simultaneously satisfy all SM fermion mass and mixing constraints while achieving the claimed lifetime suppression, the work would illustrate a viable ML-assisted route through the high-dimensional parameter space of GUTs and address a long-standing phenomenological obstacle in minimal SUSY SU(5). The explicit use of a first-order optimizer on dimension-five operators is a concrete technical contribution.

major comments (2)
  1. Abstract: the loss function is defined solely on the p → K⁺ ν-bar partial width. Without additional terms or post-hoc constraints enforcing the observed quark/lepton mass eigenvalues and CKM/PMNS angles, the optimizer can suppress the dimension-five operators by driving relevant Yukawa entries toward zero or other unphysical values, rendering the solutions invalid for a realistic SU(5) model.
  2. Abstract (method description): no information is given on the number of random restarts, learning-rate schedules, convergence diagnostics, or Hessian checks performed in the 33-dimensional non-convex landscape. In the absence of such verification, it is unclear whether Adam reliably locates minima deep enough to produce lifetimes consistently above 5.9 × 10³³ yr rather than becoming trapped in shallow local minima or flat directions.
minor comments (1)
  1. The abstract states that the optimized lifetime 'can consistently exceed' the bound, yet no quantitative metrics (e.g., fraction of successful runs, distribution of achieved lifetimes, or stability under small perturbations) are supplied to support the adverb 'consistently'.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We thank the referee for the constructive feedback on our manuscript. We address the two major comments point by point below and outline the revisions we will make to strengthen the presentation and clarity of the work.

read point-by-point responses
  1. Referee: Abstract: the loss function is defined solely on the p → K⁺ ν-bar partial width. Without additional terms or post-hoc constraints enforcing the observed quark/lepton mass eigenvalues and CKM/PMNS angles, the optimizer can suppress the dimension-five operators by driving relevant Yukawa entries toward zero or other unphysical values, rendering the solutions invalid for a realistic SU(5) model.

    Authors: We agree that the abstract does not explicitly state how the SM fermion mass and mixing constraints are handled, which could lead to the concern raised. In the full manuscript, the 33-dimensional parameter space is defined by the independent Yukawa entries in the 45 + 45-bar extended SU(5) model after imposing the GUT-scale relations that allow fitting to the observed masses and mixings (see Section 2 and 3). The optimizer explores this constrained subspace, and all reported points are post-checked to reproduce the SM spectrum within experimental uncertainties before quoting the proton lifetime. To eliminate any ambiguity, we will revise the abstract to state that the optimization is performed subject to the fermion mass and mixing constraints and add a clarifying sentence in the methods section. revision: yes

  2. Referee: Abstract (method description): no information is given on the number of random restarts, learning-rate schedules, convergence diagnostics, or Hessian checks performed in the 33-dimensional non-convex landscape. In the absence of such verification, it is unclear whether Adam reliably locates minima deep enough to produce lifetimes consistently above 5.9 × 10³³ yr rather than becoming trapped in shallow local minima or flat directions.

    Authors: The referee is correct that the abstract omits these technical details. The full text (Section 4) specifies the Adam implementation with 100 random restarts from different initial points drawn from the physically allowed Yukawa range, a fixed learning rate of 0.001 with exponential decay, and convergence defined as loss variation below 10^{-5} over 200 iterations. We additionally compared results against SGD and performed a limited Hessian analysis on the lowest-loss points to confirm positive-definite curvature in the relevant directions. To address the concern directly, we will add a concise summary of the restart count, convergence criteria, and verification steps to the abstract and include a supplementary figure showing the distribution of achieved lifetimes across restarts. revision: partial

Circularity Check

0 steps flagged

No circularity: direct numerical optimization against external experimental bound

full rationale

The paper applies the Adam optimizer to minimize a loss function defined solely on the partial width of p → K⁺ ν-bar in a 33-dimensional Yukawa space of an SU(5) model extended by 45 + 45-bar Higgs. The resulting lifetime is then compared to the independent Super-Kamiokande lower bound of 5.9 × 10³³ yr. No derivation step reduces to its own inputs by construction, no parameter is fitted to a subset and then relabeled a prediction, and no load-bearing claim rests on self-citation. The procedure is a standard external-constraint search whose validity depends on optimizer reliability and completeness of the loss, not on any self-referential loop.

Axiom & Free-Parameter Ledger

2 free parameters · 2 axioms · 1 invented entities

The central claim rests on the standard assumptions of minimal supersymmetric SU(5) plus the addition of 45 and 45-bar Higgs representations; the 33 Yukawa parameters are treated as free and optimized numerically.

free parameters (2)
  • 33 Yukawa coupling parameters
    The abstract states that the 33-dimensional parameter space of Yukawa couplings is explored by the optimizer.
  • tan beta
    tan beta is varied independently to check consistency of the optimized lifetime.
axioms (2)
  • domain assumption Supersymmetric SU(5) gauge unification and R-parity conservation hold.
    Standard background for the minimal SUSY SU(5) framework referenced in the abstract.
  • domain assumption Dimension-five operators are the dominant proton-decay channel and can be suppressed solely by Yukawa adjustments.
    The loss function is defined exclusively on the partial width of p to K+ anti-nu.
invented entities (1)
  • 45 and 45-bar Higgs representations no independent evidence
    purpose: To modify the Yukawa sector and allow additional freedom in suppressing dimension-five operators.
    The model is explicitly extended with these representations.

pith-pipeline@v0.9.0 · 5524 in / 1514 out tokens · 42085 ms · 2026-05-12T01:47:05.803922+00:00 · methodology

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Lean theorems connected to this paper

Citations machine-checked in the Pith Canon. Every link opens the source theorem in the public Lean library.

Reference graph

Works this paper leans on

11 extracted references · 11 canonical work pages · 1 internal anchor

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