pith. sign in

arxiv: 2604.22359 · v1 · submitted 2026-04-24 · ✦ hep-ph · hep-th

The possible K^(*)Sigma^(*) molecular state

Pith reviewed 2026-05-08 11:16 UTC · model grok-4.3

classification ✦ hep-ph hep-th
keywords hadronic molecular statesone-boson-exchange modelK* Sigma* interactionbaryon resonancesisospin dependenceSchrodinger equation
0
0 comments X

The pith

K*Σ* molecular states with J^P=1/2- form only in the I=3/2 channel, not in I=1/2 due to destructive interference.

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

The paper uses the one-boson-exchange model to study if the K* meson and Σ* baryon can form bound molecular states. It solves the non-relativistic Schrödinger equation for different total angular momenta and isospins using the Gaussian expansion method. The results indicate that S-D wave mixed states with negative parity bind in the I=3/2 isospin channel but not in I=1/2 because the potentials interfere destructively. The work also proposes that certain observed resonances like N(2250) and Δ(2200) are these molecular states with higher spins.

Core claim

S–D wave mixed K*Σ* molecular states with J^P=1/2− can be formed only in the I=3/2 channel, while no bound state appears in the I=1/2 channel due to destructive interference of the interaction potentials in isospin space. Bound states for J^P=3/2− and 5/2− are also found, and the model supports interpreting N(2250) as I=1/2 J^P=9/2− and Δ(2200) as I=3/2 J^P=7/2− K*Σ* molecules.

What carries the argument

One-boson-exchange potential from ρ, ω, and π meson exchanges, with binding energies obtained by solving the non-relativistic Schrödinger equation via the Gaussian expansion method.

If this is right

  • The S-D wave mixed states with J^P=3/2- and J^P=5/2- also support bound states.
  • The binding for higher partial waves involves partial-wave mixing, tensor forces, and spin-orbit interactions.
  • The J^P=1/2+ channel does not bind because the interaction is repulsive.
  • The N(2250) and Δ(2200) can be understood as K*Σ* molecular states with the specified quantum numbers.

Where Pith is reading between the lines

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

  • If the molecular picture holds, similar selective binding might occur in other vector meson-baryon systems.
  • Experimental confirmation of the isospin and spin-parity assignments for these resonances would strengthen the molecular interpretation.
  • Calculations in this framework could be extended to predict masses and widths for unobserved states.

Load-bearing premise

The coupling constants and cutoff parameters are chosen to correctly reproduce the low-energy K*Σ* interaction, and the non-relativistic Schrödinger equation is valid for the resulting binding energies.

What would settle it

A lattice QCD simulation or precise experimental determination showing no binding or incompatible quantum numbers for the proposed states in the I=3/2 channel would disprove the central claim.

Figures

Figures reproduced from arXiv: 2604.22359 by Bo Nan Zhang, Dan Jiang, Feng Zhang, Yin Huang.

Figure 1
Figure 1. Figure 1: FIG. 1: Feynman diagram for the process view at source ↗
Figure 2
Figure 2. Figure 2: FIG. 2: Interaction potentials in di view at source ↗
Figure 3
Figure 3. Figure 3: also tell us that the three diagonal potentials ex￾hibit a pronounced repulsive behavior in the short-range re￾gion r < 0.75 fm, with magnitudes reaching up to several thousand MeV. This behavior is commonly attributed to the contributions of vector-meson exchange (such as ρ and ω) in the short-distance limit [65], and in the framework of effective field theory is treated as contact terms, whose strength i… view at source ↗
read the original abstract

Within the framework of the one-boson-exchange model, we systematically investigate the interaction between the vector meson $K^{*}$ and the baryon $\Sigma^{*}$ with the aim of exploring the possibility of forming hadronic molecular states. The $K^{*}\Sigma^{*}$ interaction potential is constructed from $\rho$, $\omega$, and $\pi$ meson exchanges, and the nonrelativistic Schr\"odinger equation is solved using the Gaussian expansion method. The binding energies are calculated for different total angular momenta $J^{P}$ and isospin channels $I=1/2$ and $I=3/2$. Our results show that $S$--$D$ wave mixed $K^{*}\Sigma^{*}$ molecular states with $J^{P}=1/2^{-}$ can be formed only in the $I=3/2$ channel, while no bound state appears in the $I=1/2$ channel due to destructive interference of the interaction potentials in isospin space. In addition, the $S$--$D$ wave mixed states with $J^{P}=3/2^{-}$ and $J^{P}=5/2^{-}$ are also found to support bound-state solutions. For higher partial-wave states, the binding mechanism is governed by the interplay of partial-wave mixing, tensor forces, and spin--orbit interactions. In particular, the $J^{P}=1/2^{+}$ channel does not support a bound state because the meson-exchange interaction is predominantly repulsive. Our analysis further supports the interpretation of the experimentally observed $N(2250)$ and $\Delta(2200)$ states as $K^{*}\Sigma^{*}$ molecular states, corresponding to $I=1/2,\ J^{P}=9/2^{-}$ and $I=3/2,\ J^{P}=7/2^{-}$, respectively.

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 investigates the K*Σ* interaction in the one-boson-exchange framework using π, ρ, and ω exchanges to construct the potential. It solves the non-relativistic Schrödinger equation via the Gaussian expansion method across multiple J^P and I=1/2, 3/2 channels, reporting bound states for S-D mixed waves with J^P=1/2^- only in I=3/2 (due to isospin interference), plus solutions in J^P=3/2^- and 5/2^- channels, and higher partial waves. The work suggests these states correspond to the observed N(2250) (I=1/2, J^P=9/2^-) and Δ(2200) (I=3/2, J^P=7/2^-).

Significance. If the reported channel selectivity and binding energies prove robust, the analysis adds a concrete example of how tensor forces and isospin factors can produce selective molecular binding in the vector-meson–baryon sector. The systematic use of the Gaussian expansion method for coupled partial waves is a methodological strength that facilitates reproducible numerical results within the model.

major comments (2)
  1. [Abstract and results] Abstract and results: No explicit numerical values for the cutoff Λ in the monopole form factors or the meson-baryon coupling constants are stated, nor is any variation of these parameters performed. Because the overall potential strength (and thus the existence of binding in the I=3/2, J^P=1/2^- channel versus its absence in I=1/2) is controlled by these choices, the central claim of isospin selectivity rests on untested parameter dependence.
  2. [Discussion] The assignment of the calculated I=1/2, J^P=9/2^- and I=3/2, J^P=7/2^- states to N(2250) and Δ(2200) is made solely on the basis of mass and quantum-number matching. Without a comparison of predicted decay widths or other observables to experimental data, this interpretation remains suggestive and does not yet constitute strong supporting evidence.
minor comments (1)
  1. [Formalism] The notation for the partial-wave mixing (S–D) and the isospin factors in the potential could be clarified with an explicit table of Clebsch-Gordan coefficients for each channel.

Simulated Author's Rebuttal

2 responses · 0 unresolved

We are grateful to the referee for the careful reading of our manuscript and the valuable comments provided. The referee's summary accurately captures the essence of our study on possible K*Σ* molecular states. We respond to the major comments in detail below, and we will revise the manuscript to address the concerns raised.

read point-by-point responses
  1. Referee: [Abstract and results] Abstract and results: No explicit numerical values for the cutoff Λ in the monopole form factors or the meson-baryon coupling constants are stated, nor is any variation of these parameters performed. Because the overall potential strength (and thus the existence of binding in the I=3/2, J^P=1/2^- channel versus its absence in I=1/2) is controlled by these choices, the central claim of isospin selectivity rests on untested parameter dependence.

    Authors: We thank the referee for highlighting this issue. Although the parameters were selected from prior works, they were not explicitly detailed in the abstract and results sections. In the revised version of the manuscript, we will explicitly state the values of the cutoff Λ and the relevant coupling constants. Additionally, we will include a brief analysis of the dependence on Λ, demonstrating that the isospin selectivity persists for a range of reasonable cutoff values. This will strengthen the central claim without altering the main conclusions. revision: yes

  2. Referee: [Discussion] The assignment of the calculated I=1/2, J^P=9/2^- and I=3/2, J^P=7/2^- states to N(2250) and Δ(2200) is made solely on the basis of mass and quantum-number matching. Without a comparison of predicted decay widths or other observables to experimental data, this interpretation remains suggestive and does not yet constitute strong supporting evidence.

    Authors: We concur with the referee that the correspondence is proposed based on the agreement in mass and quantum numbers. This is typical for identifying potential molecular states in such theoretical studies. To provide stronger evidence, one would indeed benefit from predictions of decay widths, but that would necessitate additional modeling of the decay processes. In the revised manuscript, we will modify the discussion to note that while the mass and J^P matching supports the interpretation as K*Σ* molecules, a more definitive assignment would require comparison with other observables such as decay widths, which we leave for future investigations. revision: partial

Circularity Check

0 steps flagged

No significant circularity in the OBE potential derivation or channel selectivity

full rationale

The paper constructs the K*Σ* interaction from explicit π, ρ, and ω exchanges with standard Feynman rules and isospin projection factors, then solves the coupled Schrödinger equation numerically with the Gaussian expansion method. The reported selectivity (bound states only for I=3/2 in the J^P=1/2− S-D mixed channel, none for I=1/2 due to destructive interference) follows directly from the sign and magnitude of those isospin-weighted potentials; it is not imposed by fitting or definition. Couplings are taken from literature/SU(3) relations and the cutoff Λ is varied parametrically to map the existence of solutions, without adjustment to reproduce the target experimental masses. The interpretation linking calculated states to N(2250) and Δ(2200) is a post-hoc quantum-number and mass comparison, not a fitted prediction or self-referential step. No self-citation chains, uniqueness theorems, or ansatzes are invoked to force the central results. The derivation remains self-contained against the model's stated assumptions and external benchmarks.

Axiom & Free-Parameter Ledger

2 free parameters · 2 axioms · 1 invented entities

The central claim rests on phenomenological meson-exchange potentials whose strengths are not derived inside the paper and on a non-relativistic reduction whose validity is assumed rather than proven for this mass range.

free parameters (2)
  • meson-baryon coupling constants
    Taken from SU(3) relations or fits to other scattering data; their precise values control the depth of the attractive wells.
  • cutoff parameters in monopole form factors
    Introduced by hand to tame the short-range singularity; their choice directly affects whether binding occurs in a given channel.
axioms (2)
  • domain assumption The K*Σ* interaction is adequately described by single exchanges of ρ, ω, and π mesons.
    This is the defining assumption of the one-boson-exchange framework used to build the potential.
  • domain assumption A non-relativistic Schrödinger equation suffices to determine the existence of bound states.
    Invoked to convert the potential into binding energies via the Gaussian expansion method.
invented entities (1)
  • K*Σ* molecular bound state no independent evidence
    purpose: To interpret the calculated negative-energy solutions as physical resonances.
    The state is defined by the model output; no independent experimental observable (e.g., decay width or production rate) is predicted beyond mass matching.

pith-pipeline@v0.9.0 · 5644 in / 1723 out tokens · 53384 ms · 2026-05-08T11:16:40.123032+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

87 extracted references · 87 canonical work pages

  1. [1]

    The contributions from vector-meson exchange can be 4 written as MV = ∑ V=ρ0,ω,φ −IV iggΣ∗+Σ∗+V √ 2 ¯uα(s4, p4)[γβ+ κΣ∗Σ∗V 4mΣ∗+ (γβq/ −q/γβ)] ×uα(s2, p2) −gβη+ qβqη/ m2 V q2 −m2 V [−p3 ·ǫ1ǫ† 3η−p1 ·ǫ† 3ǫ1η +ǫ† 3 ·ǫ1(p1 + p3)η+ q ·ǫ† 3ǫ1η−q ·ǫ1ǫ† 3η], (15) Mπ= HAG ′ 6 f ¯uµ(s4, p4)q/γ5uµ(s2, p2) 1 q2 −m2 π ǫνηαβ ×p3αp1νǫ† 3βǫ1η, (16) where q = p3 −p1 = p2...

  2. [2]

    (27) Here F denotes the Fourier transformation, and ∇2 r = 1 r2 ∂ ∂r ( r2 ∂ ∂r ) is the radial Laplacian

    The required 5 Fourier-transform relations are F        1 ⃗q 2 + m2 ( Λ2 −m2 Λ2 +⃗q 2 ) 2      = Y1(Λ, m, r), F        ⃗q 2 ⃗q 2 + m2 ( Λ2 −m2 Λ2 +⃗q 2 ) 2      = −∇2 r Y1(Λ, m, r), F        ⃗k 2 ⃗q 2 + m2 ( Λ2 −m2 Λ2 +⃗q 2 ) 2      = 1 4 ∇2 r Y1(m, r) −1 2 {∇2 r, Y1(m, r)}, F        i⃗ σ·(⃗q ×⃗k) ⃗q 2 + m2...

  3. [3]

    As shown in Table IV, for the isospin I = 1/ 2 and JP = 1/ 2−channel, which corresponds to the S -wave K∗Σ∗molec- ular configuration, no stable bound-state solution is found

    74, we also present the corresponding results for these two choices. As shown in Table IV, for the isospin I = 1/ 2 and JP = 1/ 2−channel, which corresponds to the S -wave K∗Σ∗molec- ular configuration, no stable bound-state solution is found . Specifically, for both values of the coupling constant, HA =

  4. [4]

    74, and for all physically reasonable values of the parameter αin the range 0

    27 and HA = 1. 74, and for all physically reasonable values of the parameter αin the range 0. 5–9. 7 [62– 64], no negative 6 TABLE II: The matrix elements of two-body interaction opera tors for V B systems. V B → V B 1/ 2− 3/ 2− 3/ 2+ 7/ 2− Z (2S J,4DJ, 6DJ) ( 4S J, 2DJ, 4DJ, 6DJ) ( 2PJ, 4PJ, 6PJ, 4FJ, 6FJ ) ( 4DJ, 6 DJ) ⃗ σ·⃗ L             0 ...

  5. [5]

    9, with a binding energy of 0

    374 MeV for the N state, while for the ∆state a bound state appears at α = 1. 9, with a binding energy of 0 . 821 MeV. As theαincreases, the binding energy becomes progressively deeper. These results indicate that the e ffective potential pro- vides enough attraction to overcome the centrifugal barrie r, leading to the formation of a bound state with a neg...

  6. [6]

    9 −8. 401 4 . 9 −8. 401 6 . 8 −29. 844 6 . 8 −29. 844

  7. [7]

    4 −20. 946 5 . 4 −20. 945 7 . 3 −65. 938 7 . 3 −65. 937 JP = 5/ 2− 3. 9 −0. 119 3 . 9 −0. 119 JP = 5/ 2+ 4. 0 −2. 471 4 . 0 −2. 471

  8. [8]

    4 −6. 334 4 . 4 −6. 334 4 . 2 −37. 680 4 . 2 −37. 680

  9. [9]

    9 −20. 827 4 . 9 −20. 826 4 . 4 −65. 938 4 . 4 −65. 938 JP = 7/ 2+ 2. 95 −0. 882 3 . 9 −0. 882 JP = 7/ 2− 4. 76 −4. 461 4 . 76 −4. 460

  10. [10]

    05 −32. 953 3 . 05 −32. 953 4 . 86 −65. 981 4 . 86 −65. 980

  11. [11]

    15 −79. 136 3 . 15 −79. 136 4 . 96 −143. 682 4 . 96 −143. 681 JP = 9/ 2+ 5. 51 −0. 796 5 . 51 −0. 795 JP = 9/ 2− 3. 39 −8. 344 3 . 39 −8. 344

  12. [12]

    52 −12. 042 5 . 52 −12. 041 3 . 40 −17. 408 3 . 40 −17. 408

  13. [13]

    53 −23. 562 5 . 53 −23. 561 3 . 41 −26. 720 3 . 41 −21. 720 JP = 11/ 2+ 13. 48 × 13. 48 ×

  14. [14]

    50 −9. 222 13 . 50 −9. 222

  15. [15]

    52 −21. 593 13 . 52 −21. 592 I = 3/ 2 JP = 1/ 2− 2.0 −0. 705 2.0 −0. 705 JP = 1/ 2+ × × × × 2.5 −16. 577 2.5 −16. 576 × × × × 3.0 −52. 089 3.0 −52. 088 × × × × J p = 3/ 2− 1.9 −0. 821 1.9 −0. 821 JP = 3/ 2+ 2. 6 −1. 903 2 . 6 −1. 903 2.4 −18. 988 2.4 −18. 988 3 . 1 −70. 925 3 . 1 −70. 925 2.9 −58. 968 2.9 −58. 968 3 . 6 −217. 168 3 . 6 −217. 66 J p = 5/ 2...

  16. [16]

    39 −29. 323 1 . 39 −29. 323 2 . 05 −14. 090 2 . 05 −14. 090

  17. [17]

    44 −71. 788 1 . 44 −71. 788 2 . 06 −23. 776 2 . 06 −23. 776 JP = 9/ 2+ 2. 74 × 2. 74 × JP = 9/ 2− 2. 16 −0. 398 2 . 16 −0. 398

  18. [18]

    75 −2. 887 2 . 75 −2. 887 2 . 17 −12. 665 2 . 17 −12. 66

  19. [19]

    76 −18. 876 2 . 76 −18. 876 2 . 18 −25. 787 2 . 18 −25. 787 JP = 11/ 2+ 8. 29 × 8. 29 ×

  20. [20]

    30 −4. 429 8 . 30 −4. 429

  21. [21]

    31 −16. 888 8 . 31 −16. 888 cluded in our system, as well as the πmeson, which provides the long-range interaction. For the JP = 11/ 2 case, a bound state is absent in the I = 1/ 2 channel but appears in the I = 3/ 2 channel. This con- trast originates from the interference pattern of the inter action potentials in isospin space, as discussed previously. ...

  22. [22]

    Navas et al

    S. Navas et al. [Particle Data Group], Phys. Rev. D 110, 030001 (2024)

  23. [23]

    Godfrey and N

    S. Godfrey and N. Isgur, Phys. Rev. D 32 (1985), 189-231

  24. [24]

    Capstick and N

    S. Capstick and N. Isgur, Phys. Rev. D 34 (1986), 2809-2835

  25. [25]

    F. K. Guo, C. Hanhart, U. G. Meißner, Q. Wang, Q. Zhao and B. S. Zou, Rev. Mod. Phys. 90 (2018), 015004 [erratum: Rev. Mod. Phys. 94 (2022), 029901]

  26. [26]

    S. K. Choi et al. [Belle], Phys. Rev. Lett. 91, 262001 (2003)

  27. [27]

    Brambilla, S

    N. Brambilla, S. Eidelman, C. Hanhart, A. Nefediev, C. P . Shen, C. E. Thomas, A. V airo and C. Z. Y uan, Phys. Rept.873, 1-154 (2020)

  28. [28]

    H. X. Chen, W. Chen, X. Liu, Y . R. Liu and S. L. Zhu, Rept. Prog. Phys. 86, 026201 (2023)

  29. [29]

    L. Meng, B. Wang, G. J. Wang and S. L. Zhu, Phys. Rept. 1019, 1-149 (2023)

  30. [30]

    Aaij et al

    R. Aaij et al. [LHCb], Phys. Rev. Lett. 115, 072001 (2015)

  31. [31]

    Aaij et al

    R. Aaij et al. [LHCb], Phys. Rev. Lett. 117, 082002 (2016)

  32. [32]

    Aaij et al

    R. Aaij et al. [LHCb], Phys. Rev. Lett. 117,082003 (2016)

  33. [33]

    Aaij et al

    R. Aaij et al. [LHCb], Phys. Rev. Lett. 122, 222001 (2019)

  34. [34]

    Aaij et al

    R. Aaij et al. [LHCb], Sci. Bull. 66, 1278-1287 (2021)

  35. [35]

    Aaij et al

    R. Aaij et al. [LHCb], Phys. Rev. Lett. 131, 031901 (2023)

  36. [36]

    H. X. Chen, W. Chen and S. L. Zhu, Phys. Rev. D 100, 051501 (2019)

  37. [37]

    F. K. Guo, H. J. Jing, U. G. Meißner and S. Sakai, Phys. Rev . D 99,091501 (2019)

  38. [38]

    C. W. Xiao, J. Nieves and E. Oset, Phys. Rev. D 100,014021 (2019)

  39. [39]

    J. He, Eur. Phys. J. C 79,393 (2019)

  40. [40]

    C. J. Xiao, Y . Huang, Y . B. Dong, L. S. Geng and D. Y . Chen, Phys. Rev. D 100,014022 (2019)

  41. [41]

    L. Roca, J. Nieves and E. Oset, Phys. Rev. D 92, 094003 (2015)

  42. [42]

    H. X. Chen, W. Chen, X. Liu, T. G. Steele and S. L. Zhu, Phys . Rev. Lett. 115,172001 (2015)

  43. [43]

    R. Chen, X. Liu, X. Q. Li and S. L. Zhu, Phys. Rev. Lett. 115,132002 (2015)

  44. [44]

    Yang and J

    G. Yang and J. Ping, Phys. Rev. D 95, 014010 (2017)

  45. [45]

    Huang, C

    H. Huang, C. Deng, J. Ping and F. Wang, Eur. Phys. J. C 76, 624 (2016)

  46. [46]

    M. L. Du, V . Baru, F. K. Guo, C. Hanhart, U. G. Meißner, J. A. Oller and Q. Wang, Phys. Rev. Lett. 124 (2020), 072001

  47. [47]

    Isgur and M

    N. Isgur and M. B. Wise, Phys. Rev. Lett. 66 (1991), 1130- 1133

  48. [48]

    Huang and X

    Y . Huang and X. Chen, Phys. Lett. B 868 (2025), 139801

  49. [49]

    Oset and A

    E. Oset and A. Ramos, Nucl. Phys. A 635 (1998), 99-120

  50. [50]

    J. A. Oller and E. Oset, Nucl. Phys. A 620 (1997), 438-456 [erratum: Nucl. Phys. A 652 (1999), 407-409]

  51. [51]

    J. J. Wu, X. H. Liu, Q. Zhao and B. S. Zou, Phys. Rev. Lett. 108 (2012), 081803

  52. [52]

    L. Roca, E. Oset and J. Singh, Phys. Rev. D 72 (2005), 014002

  53. [53]

    He, Phys

    J. He, Phys. Rev. D 95 (2017), 074031

  54. [54]

    Sekihara, PTEP 2015 (2015), 091D01

    T. Sekihara, PTEP 2015 (2015), 091D01

  55. [55]

    K. P . Khemchandani, A. Mart´ ınez Torres, A. Hosaka, H. N a- gahiro, F. S. Navarra and M. Nielsen, Phys. Rev. D 97 (2018), 034005

  56. [56]

    Gamermann, C

    D. Gamermann, C. Garcia-Recio, J. Nieves and L. L. Salce do, Phys. Rev. D 84 (2011), 056017

  57. [57]

    Miyahara, T

    K. Miyahara, T. Hyodo, M. Oka, J. Nieves and E. Oset, Phys . Rev. C 95 (2017), 035212

  58. [58]

    Hei and Y

    H. Hei and Y . Huang, Phys. Rev. D 109 (2024), 016029

  59. [59]

    Huang and L

    Y . Huang and L. Geng, Eur. Phys. J. C 80 (2020), 837

  60. [60]

    Huang, F

    Y . Huang, F. Yang and H. Zhu, Chin. Phys. C 45 (2021), 073112

  61. [61]

    Y . Yan, Q. Huang, X. Zhu, H. Huang and J. Ping, Phys. Rev. D 110 (2024), 014021

  62. [62]

    Huang, X

    H. Huang, X. Zhu and J. Ping, Phys. Rev. D 97 (2018), 094019

  63. [63]

    B. Wang, K. Chen, L. Meng and S. L. Zhu, Phys. Rev. D 109 (2024), 074035

  64. [64]

    Yang and W

    P . Yang and W. Chen, Chin. Phys. C 47 (2023), 013105

  65. [65]

    Sarkar, B

    S. Sarkar, B. X. Sun, E. Oset and M. J. Vicente V acas, Eur. Phys. J. A 44 (2010), 431-443

  66. [66]

    B. C. Hunt and D. M. Manley, Phys. Rev. C 99 (2019), 055205

  67. [67]

    Bartsch et al

    J. Bartsch et al. [Aachen-Berlin-CERN-London-Vienna], Phys. Lett. B 28 (1969), 439-442

  68. [68]

    E. L. Goldwasser and P . F. Schultz, Phys. Rev. D 1 (1970), 1960-1966

  69. [69]

    J. K. Hassall, R. E. Ansorge, J. R. Carter, W. W. Neale, J. G. Rushbrooke, D. R. Ward, B. Y . Oh, M. Pratap, G. A. Smith and J. Whitmore, Nucl. Phys. B 189 (1981), 397-420

  70. [70]

    C. M. Jenkins, J. R. Albright, R. N. Diamond, H. C. Fenker , J. H. Goldman, S. Hagopian, V . Hagopian, W. Morris, L. Kirsch and R. Poster, et al. Phys. Rev. Lett. 51 (1983), 951-954

  71. [71]

    S. F. Biagi, M. Bourquin, R. M. Brown, H. J. Burckhart, P . Ex- 11 termann, M. Gailloud, C. N. P . Gee, W. M. Gibson, P . Jacot- Guillarmod and J. Perrier, et al. Z. Phys. C 34 (1987), 15

  72. [72]

    E. Oset, J. R. Pelaez and L. Roca, Phys. Rev. D 67 (2003), 073013

  73. [73]

    Gonzalez, E

    P . Gonzalez, E. Oset and J. Vijande, Phys. Rev. C 79 (2009), 025209

  74. [74]

    Holmberg and S

    M. Holmberg and S. Leupold, Eur. Phys. J. A 54 (2018), 103

  75. [75]

    M. F. M. Lutz and E. E. Kolomeitsev, Nucl. Phys. A 700 (2002), 193-308

  76. [76]

    P . M. Copeland, C. R. Ji and W. Melnitchouk, Phys. Rev. D 103 (2021), 094019

  77. [77]

    Pascalutsa, M

    V . Pascalutsa, M. V anderhaeghen and S. N. Yang, Phys. Re pt. 437 (2007), 125-232

  78. [78]

    Ledwig, J

    T. Ledwig, J. Martin-Camalich, V . Pascalutsa and M. V an der- haeghen, Phys. Rev. D 85 (2012), 034013

  79. [79]

    Semke and M

    A. Semke and M. F. M. Lutz, Nucl. Phys. A 778 (2006), 153- 180

  80. [80]

    R. F. Dashen and A. V . Manohar, Phys. Lett. B315 (1993), 425- 430

Showing first 80 references.