Pith. sign in

REVIEW 5 major objections 5 minor 65 references

Radiative decay of $\chi_{c1}$ states in effective Lagrangian approach

T0 review · 5 major / 5 minor · reviewed 2026-08-07 · deepseek-v4-flash

Pith's one-line read The paper predicts a $J/\psi\gamma$ branching fraction for the $\chi_{c1}(3872)$ about thirty times the measured value once its triangle-loop model is calibrated to the $\chi_{c1}(1P)$, and concludes that the 3872 is unlikely a $c\bar{c}$…

desk verdict Clear loop calculation with testable ratio, but the c-cbar exclusion does not follow from the computed quantity. read the letter →

arxiv 2506.08406 v1 pith:5ULO3NRZ submitted 2025-06-10 hep-ph

classification hep-ph
keywords X(3872)chi_c1(3872)radiativedecayeffectiveLagrangianapproachtriangleloopsD/D*mesonscharmoniumradialexcitationbranchingfractionvectormesondominance
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 asks whether the exotic $\chi_{c1}(3872)$ is simply the charmonium radial excitation $\chi_{c1}(2P)$. Its method is to compute radiative decays to $J/\psi\gamma$ and $\psi(2S)\gamma$ from $D$ and $D^{*}$ triangle loops in an effective-Lagrangian model, with two free cutoff parameters fixed to reproduce the measured $\chi_{c1}(1P)\to J/\psi\gamma$ branching fraction of $0.343$. With those parameters held fixed, the model predicts $R(\chi_{c1}(3872)\to J/\psi\gamma)=(3.2\pm 0.6)\times 10^{-1}$, about thirty times the observed $(10\pm 4)\times 10^{-3}$, and predicts the $\psi(2S)\gamma$ to $J/\psi\gamma$ ratio $0.109\pm 0.028$ against the measured $1.67\pm 0.21\pm 0.12\pm 0.04$. The authors therefore conclude that the $\chi_{c1}(3872)$ is unlikely to be a $c\bar{c}$ state and that its internal structure differs from that of the radial excitation $\chi_{c1}(2P)$. If correct, the result sharpens the case that the state must contain non-charmonium components such as a molecular or tetraquark admixture.

What carries the argument

The central machinery is a set of three triangle-loop amplitudes, $M_a$, $M_b$, and $M_c$, constructed from effective Lagrangians for the $\chi DD^{*}$, $\Psi DD$, $\gamma DD^{*}$, $\Psi DD^{*}$, $\gamma D^{*}D^{*}$, and $\Psi D^{*}D^{*}$ vertices, with the $\chi_{c1}DD^{*}$ coupling fixed to $21.52\,\mathrm{GeV}$ for $\chi_{c1}(1P)$ and $23\,\mathrm{GeV}$ for $\chi_{c1}(3872)$. Each loop amplitude is regulated by a monopole form factor $F(q^{2},m)=(\Lambda^{2}-m^{2})/(\Lambda^{2}-q^{2})$ with $\Lambda=m+\alpha\Lambda_{\mathrm{QCD}}$, and the two free parameters $\alpha_D$ and $\alpha_{D^{*}}$ are fixed once by reproducing the $\chi_{c1}(1P)\to J/\psi\gamma$ branching fraction. The same amplitudes with the same parameters then produce the predictions for the 3872 state.

What would settle it

Compute or measure the direct charmonium M1 amplitude, for example through a lattice QCD calculation of the $\chi_{c1}$ to $J/\psi$ radiative transition, and add it to the loop amplitudes with a natural coupling strength; if that addition restores $R(\chi_{c1}(3872)\to J/\psi\gamma)$ to about $10^{-2}$ while still reproducing $\chi_{c1}(1P)\to J/\psi\gamma$, then the paper's exclusion of a $c\bar{c}$ assignment would fail.

Watch

Extended reading notes

Core claim

The paper's central claim is that, once the effective-Lagrangian triangle-loop model is calibrated to the measured $\chi_{c1}(1P)\to J/\psi\gamma$ branching fraction, the same fixed parameters predict $R(\chi_{c1}(3872)\to J/\psi\gamma)=(3.2\pm 0.6)\times 10^{-1}$, which is about thirty times the observed $(10\pm 4)\times 10^{-3}$, and predict the $\psi(2S)\gamma$ to $J/\psi\gamma$ ratio as $0.109\pm 0.028$, about an order of magnitude below the LHCb value of $1.67\pm 0.21\pm 0.12\pm 0.04$. Since the only free parameters encode hadron-size form-factor cutoffs and are not refitted for $\chi_{c1}(3872)$, the disagreement is a structural prediction rather than a parameter artifact. The authors conclude that the $\chi_{c1}(3872)$ is unlikely a $c\bar{c}$ state and that its structure differs from that of the $\chi_{c1}(2P)$ radial excitation.

Load-bearing premise

The calculation assumes the $D$ and $D^{*}$ triangle-loop diagrams are essentially the whole story for $\chi_{c1}(3872)\to J/\psi\gamma$, so the direct short-distance charmonium M1/E1 transition is negligible; if that direct term is substantial, the predicted branching fraction could shift enough to remove the contradiction.

Editorial extensions

If this is right

  • The $\chi_{c1}(3872)$ cannot be the pure charmonium excitation $\chi_{c1}(2P)$ if the loop model is right, because the predicted $J/\psi\gamma$ rate would be some thirty times larger than what is observed.
  • The predicted $\psi(2S)\gamma$ branching fraction of $(3.5\pm 0.6)\times 10^{-2}$ is a concrete target that future measurements can confront directly.
  • The predicted ratio $R_{\Psi\gamma}\approx 0.109$ is about an order of magnitude below the measured value, so the same model that fits the $1P$ state fails on both the absolute rate and the relative rate for the 3872 state.
  • Because the two cutoff parameters are fixed once and are not refitted for $\chi_{c1}(3872)$, the mismatch is a structural signal about the state's internal composition rather than a consequence of retuning.

Reading between the lines

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

  • A natural extension the paper does not pursue is to repeat the fit with a mixed wave function containing both a $c\bar{c}$ seed and a $D\bar{D}^{*}$ component; the required admixture might be small enough to bring $R(\chi_{c1}(3872)\to J/\psi\gamma)$ down from about $0.32$ to the observed $\sim 0.01$ while keeping the $\chi_{c1}(1P)$ calibration intact.
  • The same triangle-loop machinery could be applied to related states such as the $\chi_{c2}$ candidates or to isospin-violating channels, providing cross-checks of whether the discrepancy is specific to the $1^{++}$ state.
  • The manuscript states two different values for the cutoff parameters: $\alpha_D=1.65$, $\alpha_{D^{*}}=1.01$ in the results section but $1.97$ and $1.32$ in the summary; the predictions in Table II are attached to the results-section values, so the inconsistency does not alter the reported numbers but should be corrected.
Share X Bluesky LinkedIn Reddit HN

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

5 major / 5 minor

Summary. Using an effective Lagrangian with D/D* triangle loops and a monopole form factor, the authors fit the cutoff parameters α_D=1.65 and α_D*=1.01 to the χ_c1(1P)→J/ψγ branching fraction, then predict R(χ_c1(3872)→J/ψγ)=(3.2±0.6)×10^{-1}, R(χ_c1(3872)→ψ(2S)γ)=(3.5±0.6)×10^{-2}, and R_{Ψγ}=0.109±0.028. The predicted J/ψγ fraction is about two orders of magnitude above the experimental value and the relative fraction about one order below LHCb, leading the authors to conclude that χ_c1(3872) is unlikely to be a c-cbar state.

Significance. The calculation is transparent: the amplitudes in Eqs. (4)-(6) are written out, the calibration target is explicit, and the predictions are falsifiable. If the loop-only model were complete, the disagreement with data would be a useful constraint on the composition of χ_c1(3872). However, because the direct c-cbar M1/E1 amplitude is omitted and the two-parameter fit is underdetermined by a single datum, the central conclusion does not follow from the calculated quantity. With the direct amplitude added and the parameter inconsistencies resolved, this would be a solid phenomenological study.

major comments (5)
  1. [Sec. IV vs Sec. V] The values of the fit parameters differ between Sec. IV, Eq. (11) (α_D=1.65, α_D*=1.01) and Sec. V (α_D=1.97, α_D*=1.32). Since all predictions depend on these cutoffs, the manuscript must state which set was used for Table II and reconcile the discrepancy.
  2. [Sec. IV, Eqs. (10)-(11)] Two free parameters are adjusted to a single datum, R(χ_c1(1P)→J/ψγ)=0.343, so the fit has a one-parameter degeneracy. The paper provides no criterion that selects the quoted pair. The predictions for χ_c1(3872), and R_{Ψγ} in particular, may vary along this degeneracy; please show the allowed range or add a second constraint.
  3. [Sec. II and Eqs. (4)-(6)] The amplitudes comprise only D/D* triangle loops; no direct short-distance χ_c1→J/ψγ M1/E1 amplitude is included. For χ_c1(1P) this omission means the fitted loop parameters can absorb what may be a direct c-cbar contribution, and for χ_c1(3872) any c-cbar component's direct radiative amplitude is absent. Consequently the two-order-of-magnitude excess in Table II does not by itself exclude a c-cbar assignment; adding a conventional χ_c1(2P)-like direct width of order 100 keV could remove the discrepancy. The claim in Sec. V should be reworded or the direct amplitude should be added.
  4. [Sec. IV, Eq. (7) and Table II] The branching fraction is defined as R_i=Γ_i/Γ, but no total width Γ for χ_c1(3872) is specified. Without this input, the absolute predictions in Table II are not defined; please state the total width used or quote partial widths instead.
  5. [Sec. II, Eq. (4)] The text says the cutoff Λ is typically set a few MeV above the exchanged-meson mass, but the fitted values give Λ-m=αΛ_QCD≈0.33-0.39 GeV. This inconsistency affects the claimed short-distance suppression; please clarify the intended convention.
minor comments (5)
  1. [Abstract and Sec. I] The term "effective field theory" is used loosely; the calculation is a tree-level hadronic-loop model with form factors, not a systematic EFT expansion.
  2. [Sec. IV, Eq. (10)] The uncertainty quoted as R^t=0.357±0.017 and the uncertainties in Table II are not derived anywhere; please state their source.
  3. [Sec. II, Eq. (1)] The notation for D* fields, such as D†_{αβ} and D_{μν}, is nonstandard and difficult to follow; a brief definition would help the reader.
  4. [Sec. II, Eq. (5)] The expression for M_c is very dense and the printed version has unclear parentheses in several places; please clean up the typesetting for readability.
  5. [Sec. I] The statement that LHCb [64] challenges the purely molecular interpretation should be tied to the specific measured quantity in that reference.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the chi_c1(3872) radiative fractions are genuine model outputs, not recycled fit values; the c-cbar-derived coupling is a fixed external input, and the omitted direct M1 transition is a model-completeness issue rather than a circular step.

full rationale

The derivation chain is not circular: the only parameters fitted to data are the monopole cutoffs alpha_D and alpha_D*, calibrated in Sec. IV to reproduce R(chi_c1(1P) -> J/psi gamma) = 0.343, and the chi_c1(3872) branching fractions and R_Psi_gamma are then computed with the same fixed cutoffs and are never used as fit inputs. The coupling g_chiDD*(3872) = 23 GeV quoted in Eq. (2) is imported from the external c-cbar model of Ref. [61] as a fixed hypothesis-under-test input, so the prediction R(chi_c1(3872) -> J/psi gamma) = (3.2 +/- 0.6) x 10^-1 emerges from the loop amplitudes; its disagreement with the observed (10 +/- 4) x 10^-3 is a genuine model output rather than a recycled fit. The critique that the direct M1/E1 charmonium transition is omitted is a model-completeness and correctness concern, not a circular reduction, because no target quantity is defined in terms of the paper's conclusion. There are no load-bearing self-citations: Refs. [48], [61], and [62] are external sources for the couplings. One non-circular textual inconsistency is that Sec. V restates the calibration as alpha_D = 1.97 and alpha_D* = 1.32, whereas Sec. IV reports alpha_D = 1.65 and alpha_D* = 1.01; this appears to be a typo and does not affect the circularity verdict.

Assumptions & free parameters 2 free parameters · 5 assumptions · 0 invented entities

The central prediction depends on two fitted form-factor cutoffs, the validity of effective couplings from prior literature, the dominance of triangle loops over direct charmonium transitions, and the transfer of fitted cutoffs between two different states. No new particles, fields, or conserved quantities are introduced.

free parameters (2)
  • alpha_D = 1.65 (Section IV) / 1.97 (Summary)
    Monopole form-factor cutoff parameter for the D meson in Eq. (4), Lambda = m_D + alpha_D Lambda_QCD. Fitted to the observed branching fraction of chi_c1(1P)->J/psi gamma. The two values in the paper are inconsistent.
  • alpha_D* = 1.01 (Section IV) / 1.32 (Summary)
    Form-factor cutoff parameter for the D* meson, fitted together with alpha_D to the same chi_c1(1P) branching fraction. The two values in the paper are inconsistent.
assumptions (5)
  • domain assumption The effective Lagrangians in Eq. (1), with couplings taken from refs [48,61,62], describe the chi_c1 DD*, Psi DD, Psi DD*, and Psi D* D* vertices.
    Section II, Eq. (1). The calculation relies on these vertex structures and coupling constants being correct for both chi_c1(1P) and chi_c1(3872).
  • ad hoc to paper The radiative decay amplitude is dominated by the D/D* triangle-loop diagrams in Fig. 1; the direct short-distance charmonium transition is neglected.
    Section III, only the three loop amplitudes M_a, M_b, M_c are included. This is not stated or tested as an approximation.
  • domain assumption The monopole form factor Lambda = m + alpha Lambda_QCD with Lambda_QCD = 0.2 GeV is the correct regulator for these loops.
    Eqs. (3)-(4). This is standard in the cited literature, but its systematic uncertainty is not assessed in the paper.
  • ad hoc to paper The same alpha_D and alpha_D* values fitted to chi_c1(1P) apply unchanged to chi_c1(3872).
    Section IV uses the same calibrated parameters to compute the chi_c1(3872) modes. This transferability is assumed without justification.
  • domain assumption The total width of chi_c1(3872) needed to convert the computed partial width into a branching fraction is known and correctly used.
    Eq. (7) defines R_i = Gamma_i / Gamma, but no value for Gamma(chi_c1(3872)) is stated in the paper.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Radiative decay of $\chi_{c1}$ states in effective Lagrangian approach." pith.science (2026). https://pith.science/paper/5ULO3NRZ

@misc{pith2026250608406,
  author       = {Pith},
  title        = {Pith review of: Radiative decay of $\chi_c1$ states in effective Lagrangian approach},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/5ULO3NRZ}},
  note         = {Machine review of arXiv:2506.08406}
}
abstract

The $\chi_{c1}(3872)$ state, first observed by the Belle collaboration with its quantum numbers identified as $J^{PC} = 1^{++}$, has been the subject of extensive research due to its intriguing properties. Several theoretical interpretations have been proposed to explain its unique characteristics, including the $\chi_{c1}(2P)$ assignment, a molecular $\bar{D}^{*}D/\bar{D}D^{*}$ configuration, a coupled-channel framework incorporating $c\bar{c}$ and di-meson degrees of freedom, and the compact tetraquark hypothesis. However, challenges remain in reconciling its mass coincidence with the threshold and the observed isospin violation within both the pure $c\bar{c}$ and compact tetraquark models. In this study, we examine the radiative decays of the $\chi_{c1}(1P)$ and $\chi_{c1}(3872)$ states in an effective field theory framework, incorporating triangle loops of $D$ and $D^{*}$ mesons. The model parameters are calibrated based on the observed branching fraction of the radiative decay mode $\chi_{c1}(1P) \to J/\psi \gamma$. Utilizing these fixed parameters, we predict the branching fractions $R_{\chi_{c1}(3872) \to J/\psi \gamma} \sim 10^{-1}$ and $R_{\chi_{c1}(3872) \to \psi(2S) \gamma} \sim 10^{-2}$, and the relative fraction $\mathcal{R}_{\Psi\gamma} \approx 0.109$. The work supports the argument that the $\chi_{c1}(3872)$ is unlikely a $c\bar{c}$ state.

Figures

Figures reproduced from arXiv: 2506.08406 by the authors.

Figure 1
Figure 1. FIG. 1. Feynman diagrams of the radiative decay mode [PITH_FULL_IMAGE:figures/full_fig_p002_1.png] view at source ↗

Discussion (0). Sign in to comment.

Reference graph

Works this paper leans on

65 extracted references · 29 canonical work pages

  1. [41]

    S. Y. Yu and X. W. Kang, Phys. Lett. B848, 138404 (2024) doi:10.1016/j.physletb.2023.138404 [arXiv:2308.10219 [hep-ph]]

  2. [1]

    S. K. Choiet al.[Belle], Phys. Rev. Lett.91, 262001 (2003) doi:10.1103/PhysRevLett.91.262001 [arXiv:hep- ex/0309032 [hep-ex]]

  3. [2]

    Abeet al.[Belle], Phys

    K. Abeet al.[Belle], Phys. Rev. Lett.93, 051803 (2004) doi:10.1103/PhysRevLett.93.051803 [arXiv:hep- ex/0307061 [hep-ex]]

  4. [3]

    Gokhrooet al.[Belle], Phys

    G. Gokhrooet al.[Belle], Phys. Rev. Lett.97, 162002 (2006) doi:10.1103/PhysRevLett.97.162002 [arXiv:hep- ex/0606055 [hep-ex]]

  5. [4]

    Study of the $B\to X(3872)(\to D^{*0}\bar D^0)K$ decay

    T. Aushevet al.[Belle], Phys. Rev. D81, 031103 (2010) doi:10.1103/PhysRevD.81.031103 [arXiv:0810.0358 [hep- ex]]

  6. [5]

    S. K. Choiet al.[Belle], Phys. Rev. D84, 052004 (2011) doi:10.1103/PhysRevD.84.052004 [arXiv:1107.0163 [hep- ex]]

  7. [6]

    Bhardwajet al.[Belle], Phys

    V. Bhardwajet al.[Belle], Phys. Rev. Lett.107, 091803 (2011) doi:10.1103/PhysRevLett.107.091803 [arXiv:1105.0177 [hep-ex]]

  8. [7]

    Observation of $X(3872)$ in $B \to X(3872) K\pi$ decays

    A. Balaet al.[Belle], Phys. Rev. D91, no.5, 051101 (2015) doi:10.1103/PhysRevD.91.051101 [arXiv:1501.06867 [hep-ex]]

Show all 65 references
  1. [8]

    J. H. Yinet al.[Belle], Phys. Rev. D107, no.5, 052004 (2023) doi:10.1103/PhysRevD.107.052004 [arXiv:2206.08592 [hep-ex]]

  2. [9]

    Hirataet al.[Belle], Phys

    H. Hirataet al.[Belle], Phys. Rev. D107, no.11, 112011 (2023) doi:10.1103/PhysRevD.107.112011 [arXiv:2302.02127 [hep-ex]]

  3. [10]

    Aubertet al.[BaBar], Phys

    B. Aubertet al.[BaBar], Phys. Rev. Lett.93, 041801 (2004) doi:10.1103/PhysRevLett.93.041801 [arXiv:hep- ex/0402025 [hep-ex]]

  4. [11]

    Aubertet al.[BaBar], Phys

    B. Aubertet al.[BaBar], Phys. Rev. D71, 071103 (2005) doi:10.1103/PhysRevD.71.071103 [arXiv:hep- ex/0406022 [hep-ex]]

  5. [12]

    Aubertet al.[BaBar], Phys

    B. Aubertet al.[BaBar], Phys. Rev. D74, 071101 (2006) doi:10.1103/PhysRevD.74.071101 [arXiv:hep- ex/0607050 [hep-ex]]

  6. [13]

    Aubertet al.[BaBar], Phys

    B. Aubertet al.[BaBar], Phys. Rev. D76, 071102 (2007) doi:10.1103/PhysRevD.76.071102 [arXiv:0707.1633 [hep- ex]]

  7. [14]

    Aubertet al.[BaBar], Phys

    B. Aubertet al.[BaBar], Phys. Rev. D77, 011102 (2008) doi:10.1103/PhysRevD.77.011102 [arXiv:0708.1565 [hep- ex]]

  8. [15]

    Aubertet al.[BaBar], Phys

    B. Aubertet al.[BaBar], Phys. Rev. D77, 111101 (2008) doi:10.1103/PhysRevD.77.111101 [arXiv:0803.2838 [hep- ex]]

  9. [16]

    Aubertet al.[BaBar], Phys

    B. Aubertet al.[BaBar], Phys. Rev. Lett.102, 132001 (2009) doi:10.1103/PhysRevLett.102.132001 [arXiv:0809.0042 [hep-ex]]

  10. [17]

    del Amo Sanchezet al.[BaBar], Phys

    P. del Amo Sanchezet al.[BaBar], Phys. Rev. D82, 011101 (2010) doi:10.1103/PhysRevD.82.011101 [arXiv:1005.5190 [hep-ex]]

  11. [18]

    Acostaet al.[CDF], Phys

    D. Acostaet al.[CDF], Phys. Rev. Lett.93, 072001 (2004) doi:10.1103/PhysRevLett.93.072001 [arXiv:hep- ex/0312021 [hep-ex]]

  12. [19]

    Abulenciaet al.[CDF], Phys

    A. Abulenciaet al.[CDF], Phys. Rev. Lett.96, 102002 (2006) doi:10.1103/PhysRevLett.96.102002 [arXiv:hep- ex/0512074 [hep-ex]]

  13. [20]

    Abulenciaet al.[CDF], Phys

    A. Abulenciaet al.[CDF], Phys. Rev. Lett.98, 132002 (2007) doi:10.1103/PhysRevLett.98.132002 [arXiv:hep- ex/0612053 [hep-ex]]

  14. [21]

    Aaltonenet al.[CDF], Phys

    T. Aaltonenet al.[CDF], Phys. Rev. Lett.103, 152001 (2009) doi:10.1103/PhysRevLett.103.152001 [arXiv:0906.5218 [hep-ex]]

  15. [22]

    V. M. Abazovet al.[D0], Phys. Rev. Lett.93, 162002 (2004) doi:10.1103/PhysRevLett.93.162002 [arXiv:hep- ex/0405004 [hep-ex]]

  16. [23]

    Aaboudet al.[ATLAS], JHEP01, 117 (2017) doi:10.1007/JHEP01(2017)117 [arXiv:1610.09303 [hep- ex]]

    M. Aaboudet al.[ATLAS], JHEP01, 117 (2017) doi:10.1007/JHEP01(2017)117 [arXiv:1610.09303 [hep- ex]]

  17. [24]

    Chatrchyanet al.[CMS], JHEP04, 154 (2013) 5 doi:10.1007/JHEP04(2013)154 [arXiv:1302.3968 [hep- ex]]

    S. Chatrchyanet al.[CMS], JHEP04, 154 (2013) 5 doi:10.1007/JHEP04(2013)154 [arXiv:1302.3968 [hep- ex]]

  18. [25]

    A. M. Sirunyanet al.[CMS], Phys. Rev. Lett.125, no.15, 152001 (2020) doi:10.1103/PhysRevLett.125.152001 [arXiv:2005.04764 [hep-ex]]

  19. [26]

    Aaijet al.[LHCb], Eur

    R. Aaijet al.[LHCb], Eur. Phys. J. C72, 1972 (2012) doi:10.1140/epjc/s10052-012-1972-7 [arXiv:1112.5310 [hep-ex]]

  20. [27]

    Aaijet al.[LHCb], Phys

    R. Aaijet al.[LHCb], Phys. Rev. Lett.110, 222001 (2013) doi:10.1103/PhysRevLett.110.222001 [arXiv:1302.6269 [hep-ex]]

  21. [28]

    Aaijet al.[LHCb], Nucl

    R. Aaijet al.[LHCb], Nucl. Phys. B886, 665-680 (2014) doi:10.1016/j.nuclphysb.2014.06.011 [arXiv:1404.0275 [hep-ex]]

  22. [29]

    Aaijet al.[LHCb], Phys

    R. Aaijet al.[LHCb], Phys. Rev. D92, no.1, 011102 (2015) doi:10.1103/PhysRevD.92.011102 [arXiv:1504.06339 [hep-ex]]

  23. [30]

    Aaijet al.[LHCb], Phys

    R. Aaijet al.[LHCb], Phys. Lett. B769, 305-313 (2017) doi:10.1016/j.physletb.2017.03.046 [arXiv:1607.06446 [hep-ex]]

  24. [31]

    Aaijet al.[LHCb], JHEP09, 028 (2019) doi:10.1007/JHEP09(2019)028 [arXiv:1907.00954 [hep- ex]]

    R. Aaijet al.[LHCb], JHEP09, 028 (2019) doi:10.1007/JHEP09(2019)028 [arXiv:1907.00954 [hep- ex]]

  25. [32]

    Aaijet al.[LHCb], Phys

    R. Aaijet al.[LHCb], Phys. Rev. D102, no.9, 092005 (2020) doi:10.1103/PhysRevD.102.092005 [arXiv:2005.13419 [hep-ex]]

  26. [33]

    Aaijet al.[LHCb], JHEP08, 123 (2020) doi:10.1007/JHEP08(2020)123 [arXiv:2005.13422 [hep- ex]]

    R. Aaijet al.[LHCb], JHEP08, 123 (2020) doi:10.1007/JHEP08(2020)123 [arXiv:2005.13422 [hep- ex]]

  27. [34]

    Aaijet al.[LHCb], Phys

    R. Aaijet al.[LHCb], Phys. Rev. Lett.126, no.9, 092001 (2021) doi:10.1103/PhysRevLett.126.092001 [arXiv:2009.06619 [hep-ex]]

  28. [35]

    Aaijet al.[LHCb], JHEP01, 131 (2022) doi:10.1007/JHEP01(2022)131 [arXiv:2109.07360 [hep- ex]]

    R. Aaijet al.[LHCb], JHEP01, 131 (2022) doi:10.1007/JHEP01(2022)131 [arXiv:2109.07360 [hep- ex]]

  29. [36]

    Aaijet al.[LHCb], Phys

    R. Aaijet al.[LHCb], Phys. Rev. D108, no.1, L011103 (2023) doi:10.1103/PhysRevD.108.L011103 [arXiv:2204.12597 [hep-ex]]

  30. [37]

    Aaijet al.[LHCb], JHEP04, 046 (2022) doi:10.1007/JHEP04(2022)046 [arXiv:2202.04045 [hep- ex]]

    R. Aaijet al.[LHCb], JHEP04, 046 (2022) doi:10.1007/JHEP04(2022)046 [arXiv:2202.04045 [hep- ex]]

  31. [38]

    Aaijet al.[LHCb], Phys

    R. Aaijet al.[LHCb], Phys. Rev. Lett.132, no.24, 242301 (2024) doi:10.1103/PhysRevLett.132.242301 [arXiv:2402.14975 [hep-ex]]

  32. [39]

    Barnes and S

    T. Barnes and S. Godfrey, Phys. Rev. D69, 054008 (2004) doi:10.1103/PhysRevD.69.054008 [arXiv:hep- ph/0311162 [hep-ph]]

  33. [40]

    Y. S. Kalashnikova and A. V. Nefediev, Phys. Rev. D82, 097502 (2010) doi:10.1103/PhysRevD.82.097502 [arXiv:1008.2895 [hep-ph]]

  34. [42]

    N. A. Tornqvist, Phys. Lett. B590, 209-215 (2004) doi:10.1016/j.physletb.2004.03.077 [arXiv:hep- ph/0402237 [hep-ph]]

  35. [43]

    Y. R. Liu, X. Liu, W. Z. Deng and S. L. Zhu, Eur. Phys. J. C56, 63-73 (2008) doi:10.1140/epjc/s10052-008-0640- 4 [arXiv:0801.3540 [hep-ph]]

  36. [44]

    X. Liu, Z. G. Luo, Y. R. Liu and S. L. Zhu, Eur. Phys. J. C61, 411-428 (2009) doi:10.1140/epjc/s10052-009-1020- 4 [arXiv:0808.0073 [hep-ph]]

  37. [45]

    Li and S

    N. Li and S. L. Zhu, Phys. Rev. D86, 074022 (2012) doi:10.1103/PhysRevD.86.074022 [arXiv:1207.3954 [hep- ph]]

  38. [46]

    F. K. Guo, C. Hanhart, U. G. Meißner, Q. Wang and Q. Zhao, Phys. Lett. B725, 127-133 (2013) doi:10.1016/j.physletb.2013.06.053 [arXiv:1306.3096 [hep-ph]]

  39. [47]

    F. K. Guo, C. Hanhart, Y. S. Kalashnikova, U. G. Meißner and A. V. Nefediev, Phys. Lett. B 742, 394-398 (2015) doi:10.1016/j.physletb.2015.02.013 [arXiv:1410.6712 [hep-ph]]

  40. [48]

    P. Chen, Z. W. Liu, Z. L. Zhang, S. Q. Luo, F. L. Wang, J. Z. Wang and X. Liu, Phys. Rev. D109, no.9, 094002 (2024) doi:10.1103/PhysRevD.109.094002 [arXiv:2401.05989 [hep-ph]]

  41. [49]

    Braaten and M

    E. Braaten and M. Kusunoki, Phys. Rev. D69, 074005 (2004) doi:10.1103/PhysRevD.69.074005 [arXiv:hep- ph/0311147 [hep-ph]]

  42. [50]

    Y. S. Kalashnikova, Phys. Rev. D72, 034010 (2005) doi:10.1103/PhysRevD.72.034010 [arXiv:hep- ph/0506270 [hep-ph]]

  43. [51]

    Barnes and E

    T. Barnes and E. S. Swanson, Phys. Rev. C 77, 055206 (2008) doi:10.1103/PhysRevC.77.055206 [arXiv:0711.2080 [hep-ph]]

  44. [52]

    B. Q. Li, C. Meng and K. T. Chao, Phys. Rev. D80, 014012 (2009) doi:10.1103/PhysRevD.80.014012 [arXiv:0904.4068 [hep-ph]]

  45. [53]

    P. G. Ortega, J. Segovia, D. R. Entem and F. Fernandez, Phys. Rev. D81, 054023 (2010) doi:10.1103/PhysRevD.81.054023 [arXiv:0907.3997 [hep- ph]]

  46. [54]

    V. Baru, C. Hanhart, Y. S. Kalashnikova, A. E. Kudryavtsev and A. V. Nefediev, Eur. Phys. J. A44, 93-103 (2010) doi:10.1140/epja/i2010-10929-7 [arXiv:1001.0369 [hep-ph]]

  47. [55]

    Cardoso, G

    M. Cardoso, G. Rupp and E. van Beveren, Eur. Phys. J. C75, no.1, 26 (2015) doi:10.1140/epjc/s10052-014-3254- z [arXiv:1411.1654 [hep-ph]]

  48. [56]

    Yamaguchi, A

    Y. Yamaguchi, A. Hosaka, S. Takeuchi and M. Takizawa, J. Phys. G47, no.5, 053001 (2020) doi:10.1088/1361- 6471/ab72b0 [arXiv:1908.08790 [hep-ph]]

  49. [57]

    Takeuchi, Y

    S. Takeuchi, Y. Yamaguchi, A. Hosaka and M. Takizawa, Few Body Syst.62, no.4, 77 (2021) doi:10.1007/s00601- 021-01663-8 [arXiv:2405.16794 [hep-ph]]

  50. [58]

    Maiani, F

    L. Maiani, F. Piccinini, A. D. Polosa and V. Riquer, Phys. Rev. D71, 014028 (2005) doi:10.1103/PhysRevD.71.014028 [arXiv:hep- ph/0412098 [hep-ph]]

  51. [59]

    Maiani, A

    L. Maiani, A. D. Polosa and V. Riquer, Phys. Rev. Lett. 99, 182003 (2007) doi:10.1103/PhysRevLett.99.182003 [arXiv:0707.3354 [hep-ph]]

  52. [60]

    Accardi, P

    A. Accardi, P. Achenbach, D. Adhikari, A. Afanasev, C. S. Akondi, N. Akopov, M. Albaladejo, H. Albataineh, M. Albrecht and B. Almeida-Zamora,et al.Eur. Phys. J. A60, no.9, 173 (2024) doi:10.1140/epja/s10050-024- 01282-x [arXiv:2306.09360 [nucl-ex]]

  53. [61]

    Meng and K

    C. Meng and K. T. Chao, Phys. Rev. D75, 114002 (2007) doi:10.1103/PhysRevD.75.114002 [arXiv:hep- ph/0703205 [hep-ph]]

  54. [62]

    Y. b. Dong, A. Faessler, T. Gutsche and V. E. Lyubovitskij, Phys. Rev. D77, 094013 (2008) doi:10.1103/PhysRevD.77.094013 [arXiv:0802.3610 [hep-ph]]

  55. [63]

    X. Liu, B. Zhang and S. L. Zhu, Phys. Lett. B 645, 185-188 (2007) doi:10.1016/j.physletb.2006.12.031 [arXiv:hep-ph/0610278 [hep-ph]]. 6

  56. [64]

    From these analyses, the internal structure ofχ c1(3872) may differ from that of the radial excitationχ c1(2P) state

    and result from our study are R(e) Ψγ = 1.67±0.21±0.12±0.04, R(t) Ψγ = 0.109±0.028,(12) where our prediction is about one order of magnitude below the observed value ofR Ψγ. From these analyses, the internal structure ofχ c1(3872) may differ from that of the radial excitationχ...

  57. [65]

    Bezshyikoet al.[LHCb], JHEP11, 121 (2024) doi:10.1007/JHEP11(2024)121 [arXiv:2406.17006 [hep- ex]]

    I. Bezshyikoet al.[LHCb], JHEP11, 121 (2024) doi:10.1007/JHEP11(2024)121 [arXiv:2406.17006 [hep- ex]]

Pith tools

Reviewed August 7, 2026 · model on record in the stance chip above.