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REVIEW 4 major objections 5 minor 98 references

A covariant quark-antiquark model with eight free parameters reproduces the heavy and heavy-light meson spectrum and assigns quantum numbers to newly observed states.

Reviewed by Pith at T0; open to challenge. T0 means a machine referee read the full paper against a public rubric. the ladder, T0–T4 →

T0 review · deepseek-v4-flash

2026-08-01 01:34 UTC pith:TNFVNRB5

load-bearing objection Real formalism extension with over-sold fit quality and J^P claims—worth refereeing but needs statistical backing. the 4 major comments →

arxiv 2607.25747 v1 pith:TNFVNRB5 submitted 2026-07-28 hep-ph nucl-th

Heavy and heavy-light mesons with arbitrary spin and parity in the Covariant Spectator Theory

classification hep-ph nucl-th PACS 11.10.St14.40.Pq12.39.Pn03.65.Ge
keywords heavy mesonsmeson spectrumCovariant Spectator Theoryspin-parity assignmentsquark-antiquark bound statesrunning strong couplingtensor mesonsmass predictions
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved

The pith

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

This paper extends the Covariant Spectator Theory, a relativistic bound-state framework, to mesons of any spin and parity, and adds a momentum-dependent strong coupling to the interaction kernel. The authors' central claim is that a purely scalar confining potential plus a vector one-gluon exchange, with only eight adjustable parameters, reproduces the observed masses of heavy and heavy-light mesons across seven flavor sectors. They find that even a fit to pseudoscalar states alone predicts the other channels, including tensor states, accurately. They then use the model to propose J^P assignments for states with unknown quantum numbers, including the new B_c(1P) peaks, the B_c*+ candidate, and D_s1(2933)+. If right, the model provides a practical tool for classifying newly discovered mesons and for guiding searches for unobserved states.

Core claim

The paper generalizes the one-channel Covariant Spectator Theory from J^P = 0±, 1± to arbitrary spin and parity by expanding the fully relativistic quark-antiquark wave function in a spherical-tensor basis with definite orbital and spin angular momentum. It also replaces the previously constant strong coupling in the one-gluon-exchange kernel with a running alpha_s, which makes a constant potential term redundant and leaves eight fitted parameters. Solving the resulting coupled eigenvalue equations for J^P = 0±, 1±, 2±, and 3± in sectors from bottomonium to charmed non-strange mesons, the authors argue, gives a close global description of the measured spectrum. The standout claim is that the

What carries the argument

The key object is the spherical-tensor basis for the CST wave function, built from 2x2 Pauli spin matrices and orbital partial waves and organized into four operators K^rho_j that correspond to the four possible (L,S) configurations for a given total J and natural or unnatural parity. This basis transforms the one-channel Gross equation into a linear eigenvalue problem whose solutions are meson masses and radial partial waves, thereby handling arbitrary J^P on equal footing. The other essential ingredient is the improved interaction kernel: scalar linear confinement plus vector one-gluon exchange with a momentum-dependent strong coupling and an infrared regulator, which removes the need for

Load-bearing premise

The fit assumes that the confining interaction is purely scalar, the one-gluon exchange purely vector, and quark masses constant; if any of these Lorentz-structure or mass choices is wrong, the computed spin splittings—and the quantum-number assignments built on them—would shift.

What would settle it

Measure the J^P of the two B_c(1P) peaks at 6704.8 and 6752.4 MeV and of the ATLAS state at 6339 MeV; a lower peak assigned as 2+ or a 6339 MeV state with J^P different from 1^- would contradict the model. Likewise, a confirmed D_s1(2933)+ with spin-parity other than 1+ would falsify the prediction.

Watch this falsifier — get emailed when new claim-graph text bears on it.

If this is right

  • If the central claim holds, the model supplies concrete mass predictions for dozens of unobserved heavy and heavy-light meson states in the 0±, 1±, 2±, and 3± channels.
  • The two LHCb B_c(1P) peaks at 6704.8 and 6752.4 MeV would be identified as 0+ or 1+ (lower peak) and 1+ or 2+ (higher peak), respectively, refining the allowed assignments.
  • The ATLAS state at 6339 MeV decaying to B_c+ gamma would be the long-sought B_c*+, the lowest 1^- state in the bottom-charm sector.
  • The new D_s1(2933)+ would be a 2P axial-vector (1+) charm-strange state, matching two predicted states near 2931 and 2936 MeV.
  • Because tensor and axial-tensor states are sensitive to the confining interaction, their accurate reproduction supports the scalar+vector Lorentz structure of confinement used here.

Where Pith is reading between the lines

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

  • The success of fits restricted to pseudoscalar states suggests that spin splittings in heavy mesons are dominated by the vector one-gluon-exchange structure of the kernel; if this is right, future J^P assignments can be made without relying on spin-dependent data.
  • The disappearance of the constant potential once a running coupling is introduced indicates that the earlier constant term was absorbing the missing momentum dependence, pointing toward a more physically motivated kernel.
  • The same spherical-tensor formalism could be extended by coupling to meson-meson channels above open-flavor thresholds, where the model's deviations are largest, to test whether missing thresholds—not kernel structure—explain the residual discrepancies.
  • The covariant vertex functions derived here relate invariant amplitudes to partial waves, opening the way to compute radiative and strong decay widths; measuring the decay pattern of the B_c(1P) peaks could independently distinguish the proposed 0+/1+ assignments.

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

4 major / 5 minor

Summary. This paper extends the one-channel Covariant Spectator Theory (CST) Gross equation to mesons with arbitrary spin-parity J^P up to J=3. The relativistic wave function is expanded in a spherical-tensor basis of definite L and S, yielding coupled integral equations for the four partial-wave amplitudes. The interaction kernel combines scalar linear confinement, vector one-gluon exchange with running alpha_s, and a constant term; the constant term is reported to vanish when running alpha_s is included, leaving eight adjustable parameters (string tension, alpha_s(0), four quark masses, two Pauli-Villars cutoffs). Global fits are performed to three data sets: 10 pseudoscalar states, 33 non-axial states, and 49 states of all J^P. The best model reproduces many measured masses below threshold and predicts unmeasured states, notably the B_c(1P) candidates, B_c*, and D_s1(2933)+, supporting particular J^P assignments.

Significance. If confirmed, the result is significant: a single covariant kernel with eight parameters describes heavy and heavy-light mesons with J up to 3, and the extension of CST to arbitrary J^P provides a framework for further calculations. The paper's strongest contribution is the derivation of the spherical-tensor basis and the explicit relations between covariant and partial-wave bases (Appendix B), which are nontrivial and clearly presented. The comparison of fits with 10, 33, and 49 states is a useful robustness check and shows that pseudoscalar-only fits already constrain spin-dependent channels. However, the quantitative claims—'excellent global description' and 'likely J^P assignments'—rest entirely on a fit for which no statistical measures are reported. The paper is also candid about limitations (constant quark masses, no coupled channels, approximate C-parity), but these are not propagated into the quoted few-MeV agreements. With added uncertainty quantification and a clearer statement of fitted states, the central claim could be substantiated.

major comments (4)
  1. [Section IV, Tables II–VIII] The paper reports weighted least-squares fits but provides no chi-square, no parameter uncertainties, no covariance matrix, and no explicit list of the 49 fitted states or their weights. The abstract's 'excellent global description' is therefore unverifiable. The tables themselves show deviations of 36 MeV (chi_b1(3P), Table II), 43 MeV (chi_b2(3P), Table II), 56 MeV (chi_c2(2P), Table VI), and 86 MeV (D*_s1(2860), Table VII). Because this claim is load-bearing for the proposed J^P assignments, the fit should be quantified (chi^2/dof, r.m.s. deviation, per-state residuals) and parameter uncertainties given.
  2. [Section IV.2 and Table III] The statement that the predicted masses 'agree with this interpretation to within 5 MeV' is not supported for all candidates: 3P0 at 6700 vs 6704.8 (4.8 MeV) and 3P1 at 6748 vs 6752.4 (4.4 MeV) agree, but 3P2 at 6779 vs 6752.4 is 27 MeV above. The conclusion that the upper B_c(1P) peak is '1+ or 2+' therefore requires an uncertainty estimate; with a plausible 20–30 MeV model uncertainty, the 2+ assignment would not be distinguishable. This directly affects the proposed J^P identification.
  3. [Section IV (Tables III–VIII)] The fit uses as experimental input states whose J^P assignments are themselves quark-model predictions (e.g., B_c and B_c(2S), B_s1(5830), B*_s2(5840), D*_s2(2573), D*_3(2750)). Since the model is a quark model, this creates a partial circularity when the same model is then used to recommend J^P for unconfirmed states (e.g., D_s1(2933)+, B_c(1P)). The authors should list which of the 49 fitted states have experimentally determined quantum numbers and refit using only those states as a sensitivity check.
  4. [Section V and footnote 1] The acknowledged limitations—constant quark masses, no coupling to meson-meson channels, and only approximate C-parity for J>=1 quarkonia—are not propagated into the quoted predictions. The text repeatedly notes that above-threshold states are less reliable, yet such states are included in the 49-state fit and used in assignments. The three fits (10, 33, and 49 states, Table I and Figs. 1–7) provide a natural estimate of systematic spread; the authors should report the variation of the key predictions (B_c(1P), B_c*, D_s1(2933)) across the three models.
minor comments (5)
  1. [Introduction] Typo: 'we also we refine' should be 'we also refine'.
  2. [Eq. (B30)] Several denominators read 'E1p + E1p' where one factor should presumably be E2p; please correct.
  3. [Table I and Section V] The text says 'only eight adjustable parameters' but the fit also selects N_f=2 among tried values; this should be stated as a model choice, not a fitted parameter, and the matching/threshold prescription for alpha_s at M_Z should be described.
  4. [Eq. (2.7)] Please clarify the sign convention for q^2 in the running coupling and specify whether Lambda_QCD is fixed from PDG or left free; the current description is ambiguous.
  5. [Figures 1–7] The green/blue/red symbols may be hard to distinguish in grayscale; please add explicit labels or patterns.

Circularity Check

0 steps flagged

No circular reduction found; headline predictions are out-of-sample extrapolations, and the pseudoscalar-only fit independently supports the spin-dependence claim.

full rationale

The derivation chain is not circular. Masses are obtained by solving the one-channel Gross equation (2.1) with a fixed kernel (2.3)-(2.7), and parameters are adjusted by weighted least-squares fits. The key predictive claims - B_c(1P) candidates, B_c* at 6.361 GeV, and D_s1(2933)+ - are for states not in the fitted 49-state set and appear in the assignment sections of Tables III and VII. The claim that the covariant kernel encodes spin dependence is tested out-of-sample: the fit to 10 pseudoscalar states alone already yields predictions for vector, scalar, axial-vector, and tensor channels (Sec. IV, Table I and Figs. 1-7). Self-citations to [60,61] supply the kernel form and low-J formalism, but the present paper re-derives and extends the wave functions to arbitrary J^P and reproduces low-J behavior with its own fits, so those citations are not load-bearing. The use of PDG J^P labels that are themselves quark-model assignments as fit input is a data-quality caveat, not a circular reduction, because the fitted quantities are masses, not labels. The acknowledged limitations (constant quark masses, missing coupled channels, approximate C-parity) and the absence of statistical uncertainties are correctness and robustness concerns, not circularity. No equation or prediction was found to reduce to its own input by construction.

Axiom & Free-Parameter Ledger

10 free parameters · 6 axioms · 0 invented entities

The model's central claim rests on a phenomenological kernel (Eqs. 2.3-2.6), constant quark masses, and PDG assignments for input states; these are assumptions rather than derived. The eight fitted parameters carry most of the predictive power; the invented-entities list is empty because no new degrees of freedom are introduced.

free parameters (10)
  • sigma (string tension) = 0.1755 GeV^2 (49-state fit)
    Strength of linear confining potential, adjusted to reproduce masses.
  • alpha_s(0) (via regulator tau) = 0.5225 (49-state fit)
    Value of running strong coupling at q^2=0, fitted; determines tau in Eq. (2.7).
  • light quark mass m_q = 0.197 GeV
    Constituent mass of u/d quarks, fitted.
  • strange quark mass m_s = 0.353 GeV
    Fitted.
  • charm quark mass m_c = 1.517 GeV
    Fitted.
  • bottom quark mass m_b = 4.859 GeV
    Fitted.
  • Pauli-Villars cutoff lambda_L = 2.903
    UV cutoff for confining kernel, fitted.
  • Pauli-Villars cutoff lambda_G = 2.243
    UV cutoff for OGE kernel, fitted.
  • constant interaction strength C = ≈0
    Ninth parameter fitted; consistently ≈0 and dropped from Table I.
  • number of active flavors N_f = 2
    Selected by comparing fits with N_f=2..5; not counted among the 'eight adjustable parameters' but is a model choice.
axioms (6)
  • domain assumption Gross equation (one-channel CST) is a valid 3D reduction of the Bethe-Salpeter equation for quark-antiquark bound states.
    Foundational for all calculations; taken from Refs. [52-55] and not re-derived in this paper.
  • ad hoc to paper Interaction kernel form: scalar linear confinement plus vector one-gluon exchange plus constant term (Eqs. 2.3-2.6).
    Phenomenological kernel, not derived from QCD; the Lorentz structure and confining form are assumed.
  • domain assumption Constant constituent quark masses in propagators.
    Stated in footnote 1; known to be an approximation for light/strange quarks; authors expect running masses to affect heavy-light spectra.
  • domain assumption PDG masses and J^P assignments used as fit data are correct for established states.
    Several input J^P assignments are themselves quark-model predictions (B_s, B sectors); if wrong, fit biases results.
  • domain assumption One-channel CST solutions for unnatural-parity quarkonia are approximate C-parity eigenstates.
    Acknowledged in Sec. V; exact C requires two-channel formulation; affects axial-vector and higher unnatural-parity quarkonia.
  • standard math Spherical-tensor orthonormality relations (A15-A16) and Clebsch-Gordan algebra.
    Standard angular momentum algebra; used to project coupled equations (3.22).

pith-pipeline@v1.3.0-alltime-deepseek · 35028 in / 14735 out tokens · 150193 ms · 2026-08-01T01:34:34.636612+00:00 · methodology

0 comments
read the original abstract

This work generalizes the one-channel Covariant Spectator Theory (CST) formalism to describe quark-antiquark mesons of arbitrary spin-parity $J^P$. We also improve the quark-antiquark interaction kernel by incorporating the momentum dependence of the strong coupling. Within this framework, we perform global fits to the masses of experimentally established heavy and heavy-light mesons with $J^P=0^\pm, 1^\pm, 2^\pm,$ and $3^\pm$. With only eight adjustable parameters, the model yields an excellent global description of the observed quark-antiquark spectrum and predicts both unmeasured states and likely $J^P$ assignments for states with unconfirmed quantum numbers. In particular, our results support the identifications of the recently observed $B_c(1P)^+$ candidates as $0^+$, $1^+$, and $2^+$ states, and the $B_c^{*+}$ as the lowest $1^-$ state in the bottom-charm sector, as well as the $D_{s1}(2933)^+$ as axial-vector state in the charm-strange sector.

Figures

Figures reproduced from arXiv: 2607.25747 by Alfred Stadler, Elmar P. Biernat.

Figure 1
Figure 1. Figure 1: FIG. 1: (Color online) Masses of bottomonium with [PITH_FULL_IMAGE:figures/full_fig_p007_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: FIG. 2: (Color online) Masses of [PITH_FULL_IMAGE:figures/full_fig_p009_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: FIG. 3: (Color online) Masses of [PITH_FULL_IMAGE:figures/full_fig_p011_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: FIG. 4: (Color online) Masses [PITH_FULL_IMAGE:figures/full_fig_p013_4.png] view at source ↗
Figure 5
Figure 5. Figure 5: FIG. 5: (Color online) Masses of charmonium with [PITH_FULL_IMAGE:figures/full_fig_p015_5.png] view at source ↗
Figure 6
Figure 6. Figure 6: FIG. 6: (Color online) Masses of [PITH_FULL_IMAGE:figures/full_fig_p017_6.png] view at source ↗
Figure 7
Figure 7. Figure 7: FIG. 7: (Color online) Masses of [PITH_FULL_IMAGE:figures/full_fig_p019_7.png] view at source ↗

discussion (0)

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Reference graph

Works this paper leans on

98 extracted references · 8 linked inside Pith

  1. [1]

    dominant partial wave

    (2.13) and S(k2) = m2 E2k X ρ′=± X λ′ 2=± 1 2 uρ′ 2 (k, λ′ 2)¯uρ′ 2 (k, λ′ 2) ρ′E2k −E 1k +µ−iϵ . (2.14) Substituting these in (2.1) and multiplying from the left with ¯u+ 1 (p, λ1) and from the right withu ρ 2(p, λ2) yields two coupled equations for the projected amplitudes: 4 ¯u+ 1 (p, λ1)Γ(ˆp1, p2)uρ 2(p, λ2) =− X Kρ ′λ′ 1λ′ 2 Z d3k1 (2π)3 m1 E1k m2 E2...

  2. [2]

    Bottomonium In theb ¯bsector, the fit to the pseudoscalar states alone already provides an accurate description of all measured states below threshold, including the tensor states, and yields predictions for several yet-to-be-observed states, as shown in Fig. 1. Table II compares the masses obtained from our best model—the fit to all states—with the PDG values

  3. [3]

    We additionally predict several states lying below the lowest open-flavor threshold, as shown in Fig

    Bottom-charm mesons For the two confirmedB c states,B + c andB c(2S)+, theJ P quantum numbers listed in the PDG are quark model predictions which are reproduced by our model. We additionally predict several states lying below the lowest open-flavor threshold, as shown in Fig. 2. LHCb has recently reported the first observation of orbitally excitedB + c st...

  4. [4]

    Bottom-strange mesons In theB s sector, theJ P quantum numbers of the four PDG-listed states are quark-model predictions re- quiring experimental confirmation. TheJ P assignments of the two states below threshold are reproduced by our model, and for theB s1(5830)0 (1+) andB ∗ s2(5840)0 (2+) states above threshold, our predicted masses lie below but close ...

  5. [5]

    Some devia- tion is expected, since these states lie already significantly above threshold, as shown in Fig

    Bottom mesons TheB-meson sector is similar to theB s case: the J P assignments of the PDG-listed states are only quark- model predictions, theB ± andB ∗ states lying below threshold are well described by our model, and our pre- dictions for the lowest 1 + and 2 + states lie a bit above the PDG values ofB 1(5721) andB ∗ 2 (5747). Some devia- tion is expect...

  6. [6]

    5 and Table VI)

    Charmonium In the charmonium sector, the listed states below and slightly above threshold are well described, including the lowest 2 +, 2 − and 3 − tensor states (see Fig. 5 and Table VI). Discrepancies appear higher above thresh- old in the vector, scalar, axial-vector and 2 + channels. For severalJ= 1 states. such as the vector states ψ(4230),ψ(4360), a...

  7. [7]

    By contrast, the sub-thresholdD ∗ s0(2317)± is poorly reproduced, likely owing to a significant non-q¯q component in its wave functions

    Charm-strange mesons In theD s sector, the above-threshold pseudoscalar, vector and tensor (2+ and 3−) states are reasonably well described. By contrast, the sub-thresholdD ∗ s0(2317)± is poorly reproduced, likely owing to a significant non-q¯q component in its wave functions. TheD s1(2460)± is sim- ilarly suspected of carrying a sizeable non-q¯qadmixture...

  8. [8]

    Both masses are well reproduced, whereas our predictions for the above- threshold states lie systematically below the data

    Charmed mesons Finally, in the non-strangeD-meson sector, only the lowest pseudoscalar state lies below the threshold, while the lowest vector state sits right at it. Both masses are well reproduced, whereas our predictions for the above- threshold states lie systematically below the data. The D∗ 0(2300) (0+) shows a particularly large deviation, likely r...

  9. [9]

    (ˆp1, p2), M µνσ

    are Lorentz-invariant, while Γµνσ... (ˆp1, p2), M µνσ... =M µνσ... (p) andN µνσ... =N µνσ... (p) are rank- Jcovariant tensors. Additionally, Γ 5 µνσ... (ˆp1, p2) repre- sents an axial tensor of rankJ. In Section B 2, we provide explicit expressions for the tensorsM µνσ... andN µνσ

  10. [10]

    Rank-Jpolarization tensor The rank-Jspherical polarization tensorζ (J) mJ for an- gular momentumJand projectionm J =−J, . . . , Jcan be constructed from the tensor products ofJirreducible rank-1 tensorsξ (1) λi , which we abbreviate asξ λi in the following: ζ (J) mJ ={ξ λ1 ⊗ξ λ2 ⊗ · · · ⊗ξλJ }(J) mJ ≡ 1X λ1=−1 1X λ2=−1 · · · 1X λJ =−1 2X λ12=−2 3X λ123=−3...

  11. [11]

    Lorentz-covariant tensors and axial-tensors The covariant vertex functions Γ µνσ...ω (for natu- ral parityP= (−1) J ) and Γ 5,µνσ...ω (for unnatural P= (−1) J+1 ) are symmetric Lorentz and axial ten- sors of rankJ, respectively, withJopen Lorentz indices µνσ . . . ω. For natural-parity states, the vertex func- tion Γ µνσ...ω can be expanded in terms of al...

  12. [12]

    There- fore, only four linearly independent Lorentz structures for J >0 (and two forJ= 0) in the half-off-shell 1CGE ver- tex function

    As a result, Λ(ˆp 1) appears in (2.1) and eliminates all terms in the vertex function that are pro- portional to Λ(−ˆp1), since Λ(ˆp1)Λ(−ˆp1) = 0. There- fore, only four linearly independent Lorentz structures for J >0 (and two forJ= 0) in the half-off-shell 1CGE ver- tex function. If both quark momenta are off-shell, as in the Bethe-Salpeter approach [84...

  13. [13]

    The derivation here generalizes previous calculations forJ= 0 andJ= 1 to arbitrary values ofJ

    Relations between the covariant and spherical-tensor bases Here we derive the relations between the invariant functionsG i defined in the covariant tensor basis and the radial partial wave functionsψ ρ j (p). The derivation here generalizes previous calculations forJ= 0 andJ= 1 to arbitrary values ofJ. We start by taking Diracρ-spinor matrix elements of e...

  14. [14]

    Takahashiet al.(Particle Data Group), Int

    F. Takahashiet al.(Particle Data Group), Int. J. Mod. Phys. A41, 2630011 (2026)

  15. [15]

    ATLAS Collaboration, Observation of aB ∗+ c meson with the ATLAS detector (2026), arXiv:2605.16228 [hep-ex]

  16. [16]

    Aaij et al

    R. Aaij et al. (LHCb Collaboration), Observation of a new excited charm-strange mesonD s1(2933)+ inB 0 → D+D−K +π− decays (2026), arXiv:2604.21257 [hep-ex]

  17. [17]

    Aaijet al.(LHCb), Phys

    R. Aaijet al.(LHCb), Phys. Rev. Lett.135, 231902 (2025), arXiv:2507.02149 [hep-ex]

  18. [18]

    Aaijet al.(LHCb), Phys

    R. Aaijet al.(LHCb), Phys. Rev. D112, 112003 (2025), arXiv:2507.02142 [hep-ex]

  19. [19]

    Aaijet al.(LHCb), Phys

    R. Aaijet al.(LHCb), Phys. Rev. Lett.133, 131902 (2024), arXiv:2406.03156 [hep-ex]

  20. [20]

    Aaijet al.(LHCb), Phys

    R. Aaijet al.(LHCb), Phys. Rev. Lett.126, 122002 (2021), arXiv:2011.09112 [hep-ex]

  21. [21]

    Zhang, Nuclear and Particle Physics Proceedings347, 90 (2024), 27th High-Energy Physics International in Quantum Chromodynamics

    L. Zhang, Nuclear and Particle Physics Proceedings347, 90 (2024), 27th High-Energy Physics International in Quantum Chromodynamics

  22. [22]

    Brambillaet al., Eur

    N. Brambillaet al., Eur. Phys. J. C71(2011)

  23. [23]

    Godfrey and N

    S. Godfrey and N. Isgur, Phys. Rev. D32, 189 (1985)

  24. [24]

    Barnes, S

    T. Barnes, S. Godfrey, and E. S. Swanson, Phys. Rev. D 72, 054026 (2005)

  25. [25]

    Lakhina and E

    O. Lakhina and E. S. Swanson, Phys. Letters B650, 159 (2007)

  26. [26]

    F. J. Llanes-Estrada and S. R. Cotanch, Physical Review Letters84, 1102 (2000)

  27. [27]

    F. J. Llanes-Estrada and S. R. Cotanch, Nuclear Physics A697, 303 (2002)

  28. [28]

    Di Pierro and E

    M. Di Pierro and E. Eichten, Phys. Rev. D64, 114004 (2001)

  29. [29]

    A. M. Badalian and B. L. G. Bakker, Phys. Rev. D84, 034006 (2011)

  30. [30]

    Li and K.-T

    B.-Q. Li and K.-T. Chao, Phys. Rev. D79, 094004 (2009)

  31. [31]

    Liu and M.-Z

    J.-B. Liu and M.-Z. Yang, Phys. Rev. D91, 094004 (2015)

  32. [32]

    Liu and M.-Z

    J.-B. Liu and M.-Z. Yang, Chinese Phys. C40, 073101 (2016)

  33. [33]

    Llewellyn Smith, Annals of Physics53, 521 (1969)

    C. Llewellyn Smith, Annals of Physics53, 521 (1969)

  34. [34]

    Aotsuka and Y

    T. Aotsuka and Y. Munakata, Prog. Theor. Phys.46, 897 (1971)

  35. [35]

    Huang, H.-Y

    C.-S. Huang, H.-Y. Jin, and Y.-B. Dai, Phys. Rev. D51, 2347 (1995)

  36. [36]

    R. F. Wagenbrunn and L. Y. Glozman, Phys. Rev. D75, 036007 (2007)

  37. [37]

    M. Koll, R. Ricken, D. Merten, B. Metsch, and H. Petry, Eur. Phys. J. A9, 73 (2000)

  38. [38]

    P. C. Tiemeijer and J. A. Tjon, Phys. Rev. C49, 494 (1994)

  39. [39]

    Krassnigg and M

    A. Krassnigg and M. Blank, Phys. Rev. D83, 096006 (2011)

  40. [40]

    C. S. Fischer, S. Kubrak, and R. Williams, Eur. Phys. J. A50(2014)

  41. [41]

    Popovici, T

    C. Popovici, T. Hilger, M. G´ omez-Rocha, and A. Krass- nigg, Few-Body Syst.56, 481 (2014)

  42. [42]

    Hilger, M

    T. Hilger, M. G´ omez-Rocha, and A. Krassnigg, Eur. Phys J. C77(2017)

  43. [43]

    Hagel, C

    S. Hagel, C. S. Fischer, M. Q. Huber, and J. Y. Yigzaw, The European Physical Journal A62, 129 (2026)

  44. [44]

    J. Zeng, J. W. Van Orden, and W. Roberts, Phys. Rev. D52, 5229 (1995)

  45. [45]

    Ebert, R

    D. Ebert, R. N. Faustov, and V. O. Galkin, Eur. Phys. J. C66, 197 (2010)

  46. [46]

    H. W. Crater and J. Schiermeyer, Phys. Rev. D82, 094020 (2010)

  47. [47]

    Giachetti and E

    R. Giachetti and E. Sorace, Phys. Rev. D87, 034021 (2013)

  48. [48]

    Y. Li, P. Maris, and J. P. Vary, Phys. Rev. D96, 016022 (2017)

  49. [49]

    Leit˜ ao, Y

    S. Leit˜ ao, Y. Li, P. Maris, M. T. Pe˜ na, A. Stadler, J. P. Vary, and E. P. Biernat, Eur. Phys. J. C77, 696 (2017)

  50. [50]

    Jafarzadeet al., Phys

    S. Jafarzadeet al., Phys. Rev. D103, 096027 (2021)

  51. [51]

    Jafarzadeet al., Phys

    S. Jafarzadeet al., Phys. Rev. D106, 036008 (2022)

  52. [52]

    van Beveren and G

    E. van Beveren and G. Rupp, Prog. Part. Nucl. Phys. 117, 103845 (2021)

  53. [53]

    Brambilla, A

    N. Brambilla, A. Pineda, J. Soto, and A. Vairo, Rev. Mod. Phys.77, 1423 (2005)

  54. [54]

    Colangelo and F

    P. Colangelo and F. De Fazio, Phys. Rev. D81, 094001 (2010)

  55. [55]

    Gayer, S

    L. Gayer, S. M. Ryan, D. J. Wilson, and for the Hadron Spectrum collaboration, Journal of High Energy Physics 2025, 123 (2025)

  56. [56]

    Burchet al.(Fermilab Lattice and MILC Collabora- tions), Phys

    T. Burchet al.(Fermilab Lattice and MILC Collabora- tions), Phys. Rev. D81, 034508 (2010)

  57. [57]

    R. J. Dowdallet al.(HPQCD Collaboration), Phys. Rev. D85, 054509 (2012). 27

  58. [58]

    A. Gray, I. Allison, C. T. H. Davies, E. Gulez, G. P. Lepage, J. Shigemitsu, and M. Wingate (HPQCD and UKQCD Collaborations), Phys. Rev. D72, 094507 (2005)

  59. [59]

    Lewis and R

    R. Lewis and R. M. Woloshyn, Phys. Rev. D85, 114509 (2012)

  60. [60]

    C. B. Lang, L. Leskovec, D. Mohler, S. Prelovsek, and R. M. Woloshyn, Phys. Rev. D90, 034510 (2014)

  61. [61]

    J. J. Dudek, R. G. Edwards, N. Mathur, and D. G. Richards, Phys. Rev. D77, 034501 (2008)

  62. [62]

    Liuet al.(Hadron Spectrum), J

    L. Liuet al.(Hadron Spectrum), J. High Energy Phys. 2012(126), 126

  63. [63]

    J. J. Dudek, R. G. Edwards, P. Guo, and C. E. Thomas, Physical Review D88(2013)

  64. [64]

    J. J. Dudek, R. G. Edwards, B. Jo´ o, M. J. Peardon, D. G. Richards, and C. E. Thomas (Hadron Spectrum Collab- oration), Phys. Rev. D83, 111502 (2011)

  65. [65]

    Gross, Phys

    F. Gross, Phys. Rev.186, 1448 (1969)

  66. [66]

    Gross, Phys

    F. Gross, Phys. Rev. C26, 2203 (1982)

  67. [67]

    E. P. Biernat, F. Gross, M. T. Pe˜ na, and A. Stadler, Phys. Rev. D89, 016005 (2014)

  68. [68]

    E. P. Biernat, M. T. Pe˜ na, J. E. Ribeiro, A. Stadler, and F. Gross, Phys. Rev. D90, 096008 (2014)

  69. [69]

    Gross and J

    F. Gross and J. Milana, Phys. Rev. D43, 2401 (1991)

  70. [70]

    Gross and J

    F. Gross and J. Milana, Phys. Rev. D45, 969 (1992)

  71. [71]

    Gross and J

    F. Gross and J. Milana, Phys. Rev. D50, 3332 (1994)

  72. [72]

    Savkli and F

    C. Savkli and F. Gross, Phys. Rev. C63, 035208 (2001)

  73. [73]

    Leit˜ ao, A

    S. Leit˜ ao, A. Stadler, M. Pe˜ na, and E. P. Biernat, Phys. Letters B764, 38 (2017)

  74. [74]

    Leit˜ ao, A

    S. Leit˜ ao, A. Stadler, M. T. Pe˜ na, and E. P. Biernat, Phys. Rev. D96, 074007 (2017)

  75. [75]

    Leit˜ ao, A

    S. Leit˜ ao, A. Stadler, M. T. Pe˜ na, and E. P. Biernat, Few Body Syst.58, 91 (2017)

  76. [76]

    Stadler, S

    A. Stadler, S. Leit˜ ao, M. T. Pe˜ na, and E. P. Biernat, Few Body Syst.59, 32 (2018)

  77. [77]

    E. P. Biernat, F. Gross, M. T. Pe˜ na, and A. Stadler, Phys. Rev. D89, 016006 (2014)

  78. [78]

    E. P. Biernat, F. Gross, M. T. Pe˜ na, and A. Stadler, Phys. Rev. D92, 076011 (2015)

  79. [79]

    Uzzo and F

    M. Uzzo and F. Gross, Phys. Rev. C59, 1009 (1999)

  80. [80]

    Aaijet al.(LHCb), Eur

    R. Aaijet al.(LHCb), Eur. Phys. J. C81, 601 (2021), arXiv:2010.15931 [hep-ex]

Showing first 80 references.