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Perturbative determination of CP phase in CKM matrix using rephasing invariants of hierarchical mass matrices and their inverses

T0 review · 2 major / 5 minor · reviewed 2026-07-09 · glm-5.2

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Pith's one-line read CKM CP phase reduces to a ratio of mass-matrix elements

desk verdict Compact analytic formula for CKM CP phase via perturbative SVD; internally consistent but numerically unvalidated read the letter →

arxiv 2607.06985 v1 pith:UPHUINEL submitted 2026-07-08 hep-ph

Masaki J. S. Yang This is my paper · ORCID
classification hep-ph
keywords massmatrixdeltamatricesphasesimeqbasisexpressed
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

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

The reading

The paper derives a compact formula for the CP-violating phase in the quark mixing matrix by exploiting the hierarchical structure of quark masses. The method successively integrates out heavier quark generations through a seesaw-like procedure, which naturally produces diagonalization matrices expressed in terms of both the mass matrix and its inverse. In the basis where the up-type quark mass matrix is diagonal, the CP phase in the standard PDG parametrization reduces to a fourth-order rephasing invariant built from the down-type mass matrix and its inverse: δ ≃ arg[−m⁻¹_{d12} m_{d23} / (m⁻¹_{d11} m_{d13})]. In the original Kobayashi–Maskawa parametrization, the corresponding phase is δ_KM ≃ arg[m⁻¹_{d13} m_{d33} / (m⁻¹_{d11} m_{d13})], which evaluates to approximately π/2, consistent with the known near-maximal value. The author shows that next-to-leading-order corrections are suppressed at O(λ²) ~ 4% relative to leading order, making the leading-order formula accurate to roughly the current experimental precision of about 1%.

What carries the argument

The machinery is a perturbative singular value decomposition of 3×3 hierarchical mass matrices, performed via a seesaw-like integration of heavy generations. The left-handed diagonalization matrix U_L factorizes into two unitary matrices (U_L2 U_L1) whose entries are ratios of mass-matrix elements and inverse-mass-matrix elements. The CP phase is then extracted using a rephasing-invariant formula involving the CKM matrix elements and its determinant, which avoids dependence on the choice of phase convention and isolates the physical phase directly.

What would settle it

If the actual quark mass matrices (once reconstructed from flavor-model predictions or lattice data) violate the hierarchy conditions in Eq. (8)—for instance, if off-diagonal elements are comparable to diagonal ones in some sector—then the perturbative SVD breaks down and the compact CP-phase formula no longer holds at the claimed accuracy.

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Extended reading notes

Core claim

The central result is that the CP-violating phase of the CKM matrix, when expressed through rephasing invariants, can be written directly as a ratio of entries drawn from the down-type quark mass matrix and its inverse. This works because a perturbative singular value decomposition of hierarchical mass matrices—achieved by successively integrating out heavier generations—produces left-handed mixing matrices whose entries are naturally given by elements of m and m⁻¹. In the up-diagonal basis, this collapses the CP phase to a single argument of a ratio of four matrix elements, bypassing the need for full diagonalization.

Load-bearing premise

The derivation assumes that both the up- and down-quark mass matrices satisfy a strict hierarchy where off-diagonal elements adjacent to heavier generations are at least ten times smaller than the diagonal heavy-generation elements, and that right-handed mixings are of similar size to CKM mixings. If the actual mass matrices have larger off-diagonal entries or non-trivial right-handed structure, the leading-order formula could receive corrections larger than the claimed 4%.

Editorial extensions

If this is right

  • The formula provides a direct bridge between observed CP violation and the texture of underlying quark mass matrices, useful for constraining flavor models and grand unified theories.
  • The near-maximal KM phase δ_KM ≃ π/2 is shown to arise naturally from a texture where the relative phase between the first and second generations is maximal, connecting the observed value to a specific structural assumption about mass matrices.
  • The perturbative SVD framework could be applied to the lepton sector, particularly for hierarchical neutrino mass matrices, to derive analogous phase formulae for leptonic CP violation.
  • The O(4%) NLO suppression estimate gives a concrete accuracy budget: any flavor model predicting mass matrices can be tested against the CP phase formula with known theoretical uncertainty.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • If the perturbative SVD approach were extended to scenarios with non-hierarchical or quasi-degenerate mass matrices (e.g., in the neutrino sector with normal ordering near the degenerate limit), the seesaw-like integration would break down and the compact formula would require modification or replacement.
  • The appearance of inverse-matrix elements suggests that CP-phase sensitivity to the (1,1) cofactor of the mass matrix could be exploited to probe texture-zero structures: if specific cofactors vanish or are suppressed, the formula predicts correspondingly suppressed or enhanced CP phases.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

2 major / 5 minor

Summary. This paper derives approximate analytic expressions for the CKM CP phase δ using a perturbative singular value decomposition of hierarchical quark mass matrices. The diagonalization proceeds via a seesaw-like procedure in which heavier generations are successively integrated out, naturally producing mixing matrices expressed in terms of both the mass matrix and its inverse. In the basis where the up-type mass matrix is diagonal, the PDG CP phase reduces to the fourth-order rephasing invariant δ ≃ arg[−m⁻¹_{d12} m_{d23} / (m⁻¹_{d11} m_{d13})] (Eq. 29), and the Kobayashi–Maskawa phase to δ_KM ≃ arg[m⁻¹_{d13} m_{d33} / (m⁻¹_{d11} m_{d13})] ≃ π/2 (Eq. 35). Next-to-leading-order corrections are argued to be suppressed at O(λ²) ~ 4% relative to leading order, provided right-handed mixings are of CKM order.

Significance. The paper provides a novel and direct analytic bridge between the observable CP phases and the structure of hierarchical quark mass matrices, including their inverses. The rephasing invariance of the final expressions (Eqs. 29, 35) is a genuine strength: the formula δ ≃ arg[−m⁻¹_{d12} m_{d23} / (m⁻¹_{d11} m_{d13})] is verified to be invariant under m_d → D_L m_d D_R, since both numerator and denominator acquire the same phase factor. The systematic NLO analysis in Sec. II.B, with explicit correction matrices (Eqs. 21–22), is a useful technical contribution. The connection to the well-known maximal-phase texture (Eqs. 33–37) provides additional physical context. The results are parameter-free and falsifiable by direct numerical comparison with exact diagonalization.

major comments (2)
  1. The paper lacks any numerical validation of the LO formula against exact diagonalization for a concrete hierarchical quark mass matrix. While the analytic derivation from Eqs. (2)–(15) through to Eq. (29) is internally consistent, the practical accuracy of the LO expression—and specifically whether NLO corrections truly remain at O(4%) for realistic mass matrices—cannot be assessed without at least one worked numerical example. A single table comparing the LO, NLO, and exact values of δ for a representative texture (e.g., the maximal-phase texture of Eqs. 34–37 with realistic quark masses) would substantially strengthen the central claim. This is load-bearing because the O(4%) accuracy claim is a main advertised result (abstract; end of Sec. II.B; conclusions).
  2. The NLO suppression argument at the end of Sec. II.B states that corrections are O(λ²) ~ 4% 'if the right-handed mixings are of the order of the CKM matrix.' This is an additional assumption beyond the hierarchy conditions of Eq. (8). The NLO corrections in Eqs. (21)–(22) involve ratios of singular values (e.g., m⁻¹_{11} det m / m²_{33}) whose interplay with right-handed mixing magnitudes for a generic mass matrix is not trivially O(4%). The paper should either (a) state this assumption more prominently as a condition on the validity of the LO formula, or (b) demonstrate that Eq. (8) alone suffices to bound the NLO terms, with an explicit order-of-magnitude estimate for the singular-value ratios involved.
minor comments (5)
  1. Eq. (25) is quite dense and would benefit from being broken into separate display equations for each row, or at least aligned more clearly, to improve readability.
  2. In Eq. (33), the step from the first expression to δ_KM ≃ arg[−m⁻¹_{u11} m⁻¹_{u12} / (m⁻¹_{d12} m⁻¹_{d11})] ≃ π/2 relies on the relative phase between the first and second generations being maximal, but this connection is only made explicit in the subsequent Eqs. (34)–(37). A forward reference or a brief parenthetical would help the reader follow the logic.
  3. The illustrative texture in Eqs. (34)–(37) is presented as an example, but it is not clear how generic this structure is or whether it is the only way to achieve δ_KM ≃ π/2. A brief comment on the generality (or lack thereof) would help the reader.
  4. The phrase 'the only exception is the (1,2) element of Eq. (18)' (Sec. II.B) could be clarified: the exception is that this element becomes third order once m_{13}/m_{33} is treated as second order per the hierarchy (1), but this is not immediately obvious from Eq. (18) itself.
  5. The bibliography contains a large number of self-citations ([17]–[28]) to the author's own recent work. While the rephasing-invariant formula (Eq. 26) is a mathematical identity and not circular, the density of self-citation is unusual and could be noted by the editor.

Circularity Check

0 steps flagged · score 1.0 of 10

No significant circularity: the derivation chain is internally self-consistent and the main formula is a parameter-free mathematical identity, not a fitted input renamed as prediction.

full rationale

The paper's central derivation chain proceeds as follows: (1) a perturbative SVD of hierarchical mass matrices via a seesaw-like procedure (Eqs. 2–7), adapted from Akhmedov–Frigerio–Smirnov [29] (an independent citation); (2) identification of the left-handed mixing matrix U_L in terms of the mass matrix and its inverse (Eq. 15), with the key identity m⁻¹₁₃/m⁻¹₁₁ = −(m₁₃m₂₂ − m₂₃m₁₂)/(m⁻¹₁₁ det m) shown explicitly in Eq. (16); (3) construction of the CKM matrix V_CKM = U_Lu U†_Ld (Eq. 24); and (4) evaluation of the CP phase δ using the rephasing invariant formula δ = arg[V_ud V_us V_cb V_tb / (V_ub det V_CKM)] (Eq. 26), drawn from the author's own recent work [17–22]. I checked whether any step reduces to its own inputs by construction. The rephasing invariant formula (Eq. 26) is a parameter-free mathematical identity relating the CKM matrix elements—it does not fit any parameter to data and then 'predict' a related quantity. It is an exact algebraic rearrangement of the definition of δ. The self-citations [17–22] provide the formula but the formula itself is independently verifiable algebra. The perturbative SVD technique is attributed to [29] (independent authors). The δ_KM ≈ π/2 result (Eq. 33) is shown to correspond to a known texture with a maximal relative i-phase between generations (Eqs. 34–37), which is a well-studied ansatz in the literature [56–68] by multiple independent groups. This is presented as an illustrative example, not as a derivation output claimed to be a prediction. The NLO suppression claim (O(λ²) ~ 4%) depends on an assumption about right-handed mixing magnitudes, but this is a modeling assumption about the domain of validity, not a circularity—it does not make the LO formula equivalent to its inputs by definition. No step in the chain is self-definitional, no fitted parameter is renamed as a prediction, and no load-bearing argument reduces to an unverified self-citation. The derivation is self-contained against external mathematical benchmarks.

Assumptions & free parameters 0 free parameters · 4 assumptions · 0 invented entities

No free parameters are introduced or fitted. No new physical entities are postulated. The axioms are standard domain assumptions about quark mass matrix hierarchy and perturbativity, plus one mathematical identity. The paper is a purely analytic derivation within the Standard Model framework.

assumptions (4)
  • domain assumption Quark mass matrices satisfy the hierarchy |m_{33}| ≫ |m_{23}|, |m_{32}| ≫ |m_{13}|, |m_{31}|, |m_{22}| ≫ |m_{21}|, |m_{12}| (Eq. 1)
    The entire perturbative SVD framework depends on this hierarchy holding for both up- and down-quark mass matrices. Stated in Sec. II.
  • domain assumption Perturbativity conditions |m_{i3}/m_{33}|, |m_{3j}/m_{33}| ≲ 0.1 and |m⁻¹_{12}/m⁻¹_{11}| ≲ 0.1 (Eq. 8), with Cabibbo mixing up to ~0.2
    Required for the truncation of the perturbative expansion. Stated in Sec. II after Eq. 8.
  • domain assumption Right-handed quark mixings are of the same order as CKM matrix elements
    Invoked in Sec. II.B and Sec. IV to justify that NLO corrections are suppressed by λ² ~ 4%. If right-handed mixings are larger, NLO corrections grow.
  • standard math Rephasing-invariant formula δ = arg[V_{ud}V_{us}V_{cb}V_{tb} / (V_{ub} det V)] (Eq. 26)
    Mathematical identity from [17–18]; parameter-free, not fitted. Used as the starting point for evaluating δ.

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Pith. "Pith review of Perturbative determination of CP phase in CKM matrix using rephasing invariants of hierarchical mass matrices and their inverses." pith.science (2026). https://pith.science/paper/UPHUINEL

@misc{pith2026260706985,
  author       = {Pith},
  title        = {Pith review of: Perturbative determination of CP phase in CKM matrix using rephasing invariants of hierarchical mass matrices and their inverses},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/UPHUINEL}},
  note         = {Machine review of arXiv:2607.06985}
}
abstract

In this paper, we derive approximate expressions for the CP phase $\delta$ in the CKM matrix by a perturbative singular value decomposition for hierarchical quark mass matrices $m_{q}$. The diagonalization is achieved through a seesaw-like procedure in which the heavier generations are successively integrated out, naturally leading to mixing matrices expressed in terms of the mass matrix and its inverse $m_{q}^{-1}$. As a result, in the basis where the up-type quark mass matrix is diagonal, $\delta$ is reduced to the fourth-order invariant $\delta \simeq \arg [ - m^{-1}_{d12} m_{d23}^{} / m^{-1}_{d11} m_{d13}^{} ]$, constructed from the down-type mass matrix and its inverse. Furthermore, in the Kobayashi--Maskawa parametrization, the CP phase is likewise expressed in the same basis as the invariant $\delta_{\rm KM} \simeq \arg [ m^{-1}_{d13} m_{d33}^{} / m^{-1}_{d11} m_{d13}^{} ] \simeq \pi/2$.

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Reference graph

Works this paper leans on

79 extracted references · 79 canonical work pages

  1. [1]

    Cabibbo, Phys

    N. Cabibbo, Phys. Rev. Lett.10, 531 (1963), [,648(1963)]

    work page 1963

  2. [2]

    Kobayashi and T

    M. Kobayashi and T. Maskawa, Prog. Theor. Phys.49, 652 (1973)

    work page 1973

  3. [3]

    Wu, Phys

    D.-d. Wu, Phys. Rev. D33, 860 (1986)

    work page 1986

  4. [4]

    Bernabeu, G

    J. Bernabeu, G. C. Branco, and M. Gronau, Phys. Lett. B169, 243 (1986)

    work page 1986

  5. [5]

    Gronau, A

    M. Gronau, A. Kfir, and R. Loewy, Phys. Rev. Lett.56, 1538 (1986)

    work page 1986

  6. [6]

    G. C. Branco and L. Lavoura, Phys. Lett. B208, 123 (1988)

    work page 1988

  7. [7]

    J. D. Bjorken and I. Dunietz, Phys. Rev. D36, 2109 (1987)

    work page 1987

  8. [8]

    J. F. Nieves and P. B. Pal, Phys. Rev. D36, 315 (1987)

    work page 1987

Show all 79 references
  1. [9]

    F. J. Botella and J. P. Silva, Phys. Rev. D51, 3870 (1995), arXiv:hep-ph/9411288

    1995 arXiv

  2. [10]

    Kuo and T.-H

    T.-K. Kuo and T.-H. Lee, Phys. Rev. D71, 093011 (2005), arXiv:hep-ph/0504062

    2005 arXiv

  3. [11]

    Farzan and A

    Y. Farzan and A. Yu. Smirnov, JHEP01, 059 (2007), arXiv:hep-ph/0610337

    2007 arXiv

  4. [12]

    E. E. Jenkins and A. V. Manohar, Nucl. Phys. B792, 187 (2008), arXiv:0706.4313

    2008 arXiv

  5. [13]

    G. C. Branco and M. N. Rebelo, Phys. Rev. D79, 013001 (2009), arXiv:0809.2799

    2009 arXiv

  6. [14]

    S. H. Chiu and T. K. Kuo, Phys. Lett. B760, 544 (2016), arXiv:1510.07368

    2016 arXiv

  7. [15]

    Jarlskog, Phys

    C. Jarlskog, Phys. Rev. Lett.55, 1039 (1985)

    1985

  8. [16]

    L. J. Hall and A. Rasin, Phys. Lett.B315, 164 (1993), arXiv:hep-ph/9303303

    1993 arXiv

  9. [17]

    M. J. S. Yang, Phys. Lett. B868, 139784 (2025), arXiv:2507.04720

    2025 arXiv

  10. [18]

    M. J. S. Yang, Nucl. Phys. B1020, 117187 (2025), arXiv:2509.00702

    2025

  11. [19]

    M. J. S. Yang, (2025), arXiv:2508.02058

    2025

  12. [20]

    M. J. S. Yang, PTEP2026, 021B01 (2026), arXiv:2508.10249

    2026

  13. [21]

    M. J. S. Yang, Phys. Lett. B872, 140075 (2026), arXiv:2509.11596

    2026

  14. [22]

    M. J. S. Yang, Chin. Phys.50, 011002 (2026), arXiv:2508.17866

    2026

  15. [23]

    M. J. S. Yang, PTEP2026, 061B01 (2026), arXiv:2512.14074

    2026

  16. [24]

    M. J. S. Yang, (2025), arXiv:2512.20889

    2025

  17. [25]

    M. J. S. Yang, PTEP2026, 031B01 (2026), arXiv:2601.09389

    2026

  18. [26]

    M. J. S. Yang, Nucl. Phys. B1028, 117494 (2026), arXiv:2602.14513

    2026 arXiv

  19. [27]

    M. J. S. Yang, (2026), arXiv:2603.08071

    2026

  20. [28]

    M. J. S. Yang, (2026), arXiv:2606.00980

    2026 arXiv

  21. [29]

    E. K. Akhmedov, M. Frigerio, and A. Y. Smirnov, JHEP09, 021 (2003), arXiv:hep-ph/0305322

    2003 arXiv

  22. [30]

    Di Bari, Nucl

    P. Di Bari, Nucl. Phys. B727, 318 (2005), arXiv:hep-ph/0502082

    2005 arXiv

  23. [31]

    Vives, Phys

    O. Vives, Phys. Rev.D73, 073006 (2006), arXiv:hep-ph/0512160

    2006 arXiv

  24. [32]

    Di Bari and A

    P. Di Bari and A. Riotto, Phys. Lett. B671, 462 (2009), arXiv:0809.2285

    2009 arXiv

  25. [33]

    Bertuzzo, P

    E. Bertuzzo, P. Di Bari, and L. Marzola, Nucl. Phys. B849, 521 (2011), arXiv:1007.1641

    2011 arXiv

  26. [34]

    Di Bari and A

    P. Di Bari and A. Riotto, JCAP04, 037 (2011), arXiv:1012.2343

    2011 arXiv

  27. [35]

    Di Bari and L

    P. Di Bari and L. Marzola, Nucl. Phys. B877, 719 (2013), arXiv:1308.1107

    2013 arXiv

  28. [36]

    Di Bari, S

    P. Di Bari, S. King, and M. Re Fiorentin, JCAP03, 050 (2014), arXiv:1401.6185

    2014 arXiv

  29. [37]

    Di Bari, L

    P. Di Bari, L. Marzola, and M. Re Fiorentin, Nucl. Phys. B893, 122 (2015), arXiv:1411.5478

    2015 arXiv

  30. [38]

    Di Bari and M

    P. Di Bari and M. Re Fiorentin, JHEP10, 029 (2017), arXiv:1705.01935

    2017 arXiv

  31. [39]

    Chianese and P

    M. Chianese and P. Di Bari, JHEP05, 073 (2018), arXiv:1802.07690

    2018 arXiv

  32. [40]

    Di Bari, Prog

    P. Di Bari, Prog. Part. Nucl. Phys.122, 103913 (2022), arXiv:2107.13750

    2022 arXiv

  33. [41]

    Koide, Phys

    Y. Koide, Phys. Lett.B607, 123 (2005), arXiv:hep-ph/0411280

    2005 arXiv

  34. [42]

    Koide and H

    Y. Koide and H. Nishiura, Phys. Rev. D79, 093005 (2009), arXiv:0811.2839

    2009 arXiv

  35. [43]

    Hocker and Z

    A. Hocker and Z. Ligeti, Ann. Rev. Nucl. Part. Sci.56, 501 (2006), arXiv:hep-ph/0605217

    2006 arXiv

  36. [44]

    P. H. Frampton and X.-G. He, Phys. Lett. B688, 67 (2010), arXiv:1003.0310

    2010 arXiv

  37. [45]

    Dueck, S

    A. Dueck, S. Petcov, and W. Rodejohann, Phys. Rev. D82, 013005 (2010), arXiv:1006.0227

    2010 arXiv

  38. [46]

    P. H. Frampton and X.-G. He, Phys. Rev. D82, 017301 (2010), arXiv:1004.3679

    2010 arXiv

  39. [47]

    Li and B.-Q

    S.-W. Li and B.-Q. Ma, Phys. Lett. B691, 37 (2010), arXiv:1003.5854. 9

    2010 arXiv

  40. [48]

    Qin and B

    N. Qin and B. Q. Ma, Phys. Lett. B702, 143 (2011), arXiv:1106.3284

    2011 arXiv

  41. [49]

    Zhou, Phys

    Y.-L. Zhou, Phys. Rev. D84, 113012 (2011), arXiv:1110.5023

    2011 arXiv

  42. [50]

    Qin and B.-Q

    N. Qin and B.-Q. Ma, Phys. Rev. D83, 033006 (2011), arXiv:1101.4729

    2011 arXiv

  43. [51]

    Qin and B.-Q

    N. Qin and B.-Q. Ma, Phys. Lett. B695, 194 (2011), arXiv:1011.6412

    2011 arXiv

  44. [52]

    Zhang and B.-Q

    X. Zhang and B.-Q. Ma, Phys. Lett. B713, 202 (2012), arXiv:1203.2906

    2012 arXiv

  45. [53]

    Li, H.-H

    G.-N. Li, H.-H. Lin, D. Xu, and X.-G. He, Int. J. Mod. Phys. A28, 1350014 (2013), arXiv:1204.1230

    2013 arXiv

  46. [54]

    Zhang and B.-Q

    X. Zhang and B.-Q. Ma, The Universe1, 16 (2013), arXiv:1204.6604

    2013 arXiv

  47. [55]

    Bonaet al., Rend

    UTfit, M. Bonaet al., Rend. Lincei Sci. Fis. Nat.34, 37 (2023), arXiv:2212.03894

    2023 arXiv

  48. [56]

    Shin, Phys

    M. Shin, Phys. Lett. B160, 411 (1985)

    1985

  49. [57]

    Gronau, R

    M. Gronau, R. Johnson, and J. Schechter, Phys. Rev. Lett.54, 2176 (1985)

    1985

  50. [58]

    Fritzsch, Phys

    H. Fritzsch, Phys. Rev.D32, 3058 (1985)

    1985

  51. [59]

    Kang and M

    K. Kang and M. Shin, Phys. Lett. B165, 383 (1985)

    1985

  52. [60]

    Lehmann, C

    H. Lehmann, C. Newton, and T. T. Wu, Phys. Lett. B384, 249 (1996)

    1996

  53. [61]

    Kang and S

    K. Kang and S. K. Kang, Phys. Rev.D56, 1511 (1997), arXiv:hep-ph/9704253

    1997 arXiv

  54. [62]

    Fritzsch and Z.-z

    H. Fritzsch and Z.-z. Xing, Phys. Rev. D61, 073016 (2000), arXiv:hep-ph/9909304

    2000 arXiv

  55. [63]

    Xing and H

    Z.-z. Xing and H. Zhang, J. Phys. G30, 129 (2004), arXiv:hep-ph/0309112

    2004 arXiv

  56. [64]

    Antusch, S

    S. Antusch, S. F. King, M. Malinsky, and M. Spinrath, Phys. Rev. D81, 033008 (2010), arXiv:0910.5127

    2010 arXiv

  57. [65]

    Tanimoto and K

    M. Tanimoto and K. Yamamoto, JHEP04, 037 (2015), arXiv:1501.07717

    2015 arXiv

  58. [66]

    M. J. S. Yang, Phys. Lett. B806, 135483 (2020), arXiv:2002.09152

    2020 arXiv

  59. [67]

    M. J. S. Yang, Chin. Phys. C45, 043103 (2021), arXiv:2003.11701

    2021 arXiv

  60. [68]

    M. J. S. Yang, Nucl. Phys. B972, 115549 (2021), arXiv:2103.12289

    2021 arXiv

  61. [69]

    P. B. Denton, S. J. Parke, T. Tao, and X. Zhang, Bull. Am. Math. Soc.59, 31 (2022), arXiv:1908.03795

    2022 arXiv

  62. [70]

    A. M. Abdullahi and S. J. Parke, Eur. Phys. J. C84, 707 (2024), arXiv:2212.12565

    2024 arXiv

  63. [71]

    S.-F. Ge, D. A. Dicus, and W. W. Repko, Phys. Rev. Lett.108, 041801 (2012), arXiv:1108.0964

    2012 arXiv

  64. [72]

    S. T. Petcov, Nucl. Phys. B892, 400 (2015), arXiv:1405.6006

    2015 arXiv

  65. [73]

    P. P. Novichkov, S. T. Petcov, and M. Tanimoto, Phys. Lett. B793, 247 (2019), arXiv:1812.11289

    2019 arXiv

  66. [74]

    Ge, C.-F

    S.-F. Ge, C.-F. Kong, and J. P. Pinheiro, (2025), arXiv:2511.15442

    2025

  67. [75]

    Dutta, S

    D. Dutta, S. Goswami, M. Kashav, and K. M. Patel, (2026), arXiv:2601.18397

    2026

  68. [76]

    Ecker, W

    G. Ecker, W. Grimus, and H. Neufeld, Nucl. Phys. B247, 70 (1984)

    1984

  69. [77]

    Gronau and R

    M. Gronau and R. N. Mohapatra, Phys. Lett. B168, 248 (1986)

    1986

  70. [78]

    Feruglio, C

    F. Feruglio, C. Hagedorn, and R. Ziegler, JHEP07, 027 (2013), arXiv:1211.5560

    2013 arXiv

  71. [79]

    Holthausen, M

    M. Holthausen, M. Lindner, and M. A. Schmidt, JHEP04, 122 (2013), arXiv:1211.6953

    2013 arXiv

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