arXiv subjects

Dian-Yong Chen

Publications and source records attributed to Dian-Yong Chen.

At least 19 recordsLinked to original sources

arXiv2026

Radiative decays of the predicted P-wave $D\bar{D}^*$ molecular state: the $0^{-+}$ case

In the present work, we study the radiative decays of the P-wave $D\bar{D}^*$ molecular state $G_0$ with $I^G(J^{PC})=0^+(0^{-+})$ using a phenomenological Lagrangian approach. The molecular coupling is fixed by the compositeness condition with a Gaussian form factor. The partial widths for $G_0\to γγ$, $γJ/ψ$, $γψ(2S)$, $γh_c$, $γρ$, and $γω$ are evaluated. Our results show that the two-photon and $γh_c$ channels are highly suppressed, while $γJ/ψ$, $γψ(2S)$, and $γρ$ are of the order of a few keV, and $γω$ reaches several tens of keV, making it the dominant radiative mode. The ratios $Γ(G_0 \to γψ(2S))/Γ(G_0 \to γJ/ψ)$ and $Γ(G_0 \to γω)/Γ(G_0 \to γρ)$ are predicted to be 1-2.6 and 3.4-5.4, respectively, with mild parameter dependence. We also compare with hadronic decays and find that the total radiative decay width is lower than the hadronic decay widths by about one order of magnitude. We propose searching for $G_0$ in the sequential decay $Y(4230)\to γG_0 \to γωJ/ψ$, which is accessible to further experimental measurements by the BESIII, Belle II and LHCb Collaborations.

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arXiv2026

$P_{c}(4312)$, $P_{c}(4440)$, and $P_{c}(4457)$ productions in $e^{+} e^{-}$ collisions

In the present work, we propose to investigate the productions of $P_{c}(4312)$, $P_{c}(4440)$, and $P_{c}(4457)$ in the $e^{+} e^{-} \rightarrow p \bar{p} J/ψ$ process by utilizing an effective Lagrangian approach, where $P_{c}(4312)$ is considered as $Σ_{c} \bar{D}$ molecular state with $J^{P}=1/2^{-}$, while $P_{c}(4440)$ and $P_{c}(4457)$ are considered as $Σ_{c} \bar{D}^{\ast}$ molecular states with $J^{P}=1/2^{-}$ and $J^{P}=3/2^{-}$, respectively. For the $e^{+} e^{-} \rightarrow \bar{p} P_{c}(4312)$, $e^{+} e^{-} \rightarrow \bar{p} P_{c}(4440)$, and $e^{+} e^{-} \rightarrow \bar{p} P_{c}(4457)$ processes, the cross sections are evaluated to be ($27.8^{+42.2}_{-17.9}$) fb, ($38.7^{+58.6}_{-25.1}$) fb, and ($1.44^{+2.18}_{-0.93}$) fb at $\sqrt{s}=6$ GeV, respectively, where the central values are estimated with $Λ_{r}=2.5$ GeV, and the uncertainties are resulted from the variations of $Λ_{r}$ from 2.0 to 3.0 GeV. Considering that the $P_{c}$ states can decay into $J/ψp$, we estimate the cross sections for $e^{+} e^{-} \rightarrow p \bar{p} J/ψ$ and the differential cross sections depending on the $J/ψp$ invariant mass. At $\sqrt{s}=6$ GeV, the cross sections for $e^{+} e^{-} \rightarrow p \bar{p} J/ψ$ are estimated to be ($14.7^{+22.2}_{-9.50}$) fb. Moreover, our estimations indicate that the cross section resulted from the $P_{c}(4440)$ and $\bar{P}_{c}(4440)$ intermediate states is dominant. In the $J/ψp$ invariant mass spectrum, our estimations reveal that the peak structure between 4.42 and 4.46 GeV primarily originates from $P_{c}(4440)$.

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arXiv2026

Unquenched Charmonium and Beyond

The year 2024 marked the 50th anniversary of the discovery of the $J/ψ$ particle, which unveiled the charm quark and the charmonium spectrum, instigating the "November Revolution" in particle physics. This discovery catalyzed the development of quenched potential models, most notably the Cornell model, which provided a foundational quantitative description of the hadronic spectrum. However, the landscape of hadron spectroscopy has been profoundly transformed since the turn of the 21st century with the observation of numerous charmonium-like states, such as $X(3872)$, which exhibit properties starkly at odds with quenched model predictions. These discrepancies, exemplified by the "$X(3872)$ low-mass puzzle" and the "$Y$ problem" associated with vector states like $Y(4260)$, underscore the critical limitations of the quenched approximation and signal the necessity for a new theoretical paradigm. This review synthesizes recent advances in hadronic spectroscopy, arguing that the unquenched picture, which incorporates coupled-channel effects such as hadronic loops, is essential for a unified description of these new states and associated anomalies. We demonstrate how unquenched effects provide compelling solutions to long-standing puzzles in charmonium decays (e.g., the "$ρπ$ puzzle" and anomalous dipion transitions), predict and explain the existence of exotic charged states like $Z_c(3900)$ and $Z_b(10610)$ via mechanisms such as Initial Single Pion Emission, and offer a framework for understanding interactions between charmonia and with nucleons. Furthermore, we emphasize the universality of unquenched effects, extending their application to bottomonium and light-flavor sectors. As experimental precision continues to improve, we advocate for the systematic development of unquenched hadronic spectroscopy.

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arXiv2026

Strong decays of the possible $D^{}K$ and $\bar{D}^{}K$ molecules

Inspired by the rich spectrum of structures near the $D^{(*)}K^{(*)}/\bar{D}^{(*)}K^{(*)}$ thresholds, we postulate the existence of $S$-wave $D^{*}K$ and $\bar{D}^{*}K$ molecules, denoted as $T_{c\bar{s}1}^{f}(2460)$ with $I=0$ (corresponding to $D_{s1}(2460)$), $T_{c\bar{s}1}^{a}(2470)$ with $I=1$, $T_{\bar{c}\bar{s}1}^{f}(2460)$ with $I=0$, and $T_{\bar{c}\bar{s}1}^{a}(2470)$ with $I=1$, respectively. Using an effective Lagrangian approach, we investigate the strong decays of these molecular states. Our estimates indicate that the width of $T_{c\bar{s}1}^{a}(2470)$ is roughly three orders of magnitude larger than that of $T_{c\bar{s}1}^{f}(2460)$, while the widths of $T_{\bar{c}\bar{s}1}^{a/f}(2470)$ are of the same orders as that of $T_{c\bar{s}1}^{f}(2460)$. The present study may provide valuable clues for the experimental search for these molecular candidates.

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arXiv2026

$T_{\bar{c}\bar{s}1}^f(2750)$ production in the $B^+$ decays processes

In the present work, we studied the \tcs state production through the meson loop mechanism in the $B^+$ meson decays, where \tcs is considered as a $\bar{D}K^*$ molecular state with $J^P=1^+$. By employing the effective Lagrangian approach, we estimated the branching ratio of the $B^+ \to D^+ T_{\bar{c}\bar{s}1}^0 $ and $B^+ \to D^{*+} T_{\bar{c}\bar{s}1}^0$ processes and found them to be on the order of $10^{-5}\sim 10^{-4}$. The fit fraction of \tcs in different processes was also estimated. We propose to search for \tcs in the $B^+ \to D^{*+}\bar{D}^{*-}K^+$ process, which should be accessible to the Belle II and LHCb Collaborations.

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arXiv2026

Analysis of the semileptonic decays $Σ_b\toΣ_cl\barν_l$, $Ξ'_b\toΞ'_cl\barν_l$ and $Ω_b\toΩ_cl\barν_l$ in QCD sum rules

In this article, the electroweak transition form factors of $Σ_b\toΣ_c$, $Ξ'_b\toΞ'_c$ and $Ω_b\toΩ_c$ are analyzed within the framework of three-point QCD sum rules. In phenomenological side, all possible couplings of interpolating current to hadronic states are considered, and the Dirac structure dependence on the form factors is systematically eliminated. In QCD side, our calculation incorporates both the perturbative part and the contributions from vacuum condensates up to dimension 8. This systematic inclusion of higher-dimensional terms accounts for a broader set of Feynman diagrams, thereby enhancing the comprehensiveness and reliability of the operator product expansion. Using the obtained form factors, we study the partial widths of semileptonic decays $Σ_b\toΣ_cl\barν_l$, $Ξ'_b\toΞ'_cl\barν_l$ and $Ω_b\toΩ_cl\barν_l$ ($l=e$, $μ$ and $τ$). The results indicate that these decay widths approximately satisfy SU(3) flavor symmetry. Next, we calculate the branching ratios for the decay process $Ω_b\toΩ_cl\barν_l$ and compare them with the results from other collaborations. Furthermore, the lepton universality ratios and some asymmetry parameters of these decay processes are also analyzed, which provide information for the study of new physics. We hope that these results will serve as a useful reference for future theoretical and experimental studies of weak decays involving heavy flavor baryons.

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arXiv2026

Finding a clean process $B^- \to K^- D^0 K^0$ to probe absolutely exotic four-quark states

Motivated by the observations of $T_{c\bar{s}0}(2900)^0$ and $T_{c\bar{s}0}(2900)^{++}$, we propose to search for $\tcsbar^0$ in the cleaner process $B^- \to K^- D^0 K^0$. In the $D^*K^*$ molecular picture, our estimates suggest that $T_{c\bar{s}0}(2900)^0$ should contribute significantly to the $D^0 K^0$ invariant mass distribution in $B^- \to K^- D^0 K^0$, as reported by the Belle II Collaboration. The corresponding fit fraction is estimated to be $(9.72\pm 3.92)\%$ or $(7.09\pm 5.88)\%$ in different fitting schemes. Further precise measurements of this process at Belle II and LHCb could be helpful for clarifying the nature of $T_{c\bar{s}0}(2900)$.

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arXiv2026

Systematic analysis of the form factors of $B_{c}$ to $P$-wave charmonia and corresponding weak decays

In this article, the vector, axial vector and tensor form factors of $B_{c}\to χ_{cJ}$ ($J=0,1,2$) and $B_{c}\to h_{c}$ are analyzed within the framework of three-point QCD sum rules. With the calculated vector and axial vector form factors, we directly study the decay widths and branching ratios of semileptonic decays $B_{c}^{-}\to χ_{cJ}l \barν_l, h_{c}l \barν_l$ $(l=e, μ$ and $τ)$ and analyze the nonleptonic decays $B_{c}^{-}\to χ_{cJ}π^{-}, χ_{cJ}K^{-}, χ_{cJ}ρ^{-}, χ_{cJ}K^{*-}$, $B_{c}^{-}\to h_{c}π^{-}, h_{c}K^{-}, h_{c}ρ^{-}, h_{c}K^{*-}$ by using the naive factorization approach (NFA). These results can provide more information to understand the properties of $B_{c}$ meson and $P$-wave charmonia and to study the heavy quark dynamics.

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arXiv2026

$Λ_{c}(2910)$ and $Λ_{c}(2940)$ productions in $p \bar{p}$ annihilation

In this work, we investigate the productions of $Λ_{c}(2910)$ and $Λ_{c}(2940)$ in the $p \bar{p} \rightarrow \barΛ_{c} D^{0} p$ process by utilizing an effective Lagrangian approach, where both $Λ_{c}(2910)$ and $Λ_{c}(2940)$ are considered as $D^{\ast}N$ molecular states with $J^{P}=1/2^{-}$ and $3/2^{-}$, respectively. In addition to the $t$-channel $D$ and $D^{\ast}$ exchanges, the contribution from light-meson exchange is also considered. At $\sqrt{s}=10$ $\mathrm{GeV}$, our estimations indicate that the total cross sections for $p \bar{p} \rightarrow \barΛ_{c} D^{0} p$ are $(130.7^{+397.1}_{-103.9})$ nb, where the central value is estimated with $Λ_{r}=1.1$ GeV, and the uncertainties are resulted from the variation of parameter $Λ_{r}$ from 1.0 GeV to 1.2 GeV. Our results indicate that the light meson exchange diagrams are very important, which provide a very large smooth background. Moreover, the estimations of the $D^{0}p$ invariant mass spectrum reveal that the peak structure between 2.9 and 3.0 GeV primarily originates from $Λ_c(2910)$, while the signal of $Λ_{c}(2940)$ is about one order smaller than that of $Λ_{c}(2910)$. Furthermore, the resulting Dalitz plot is estimated with $\sqrt{s}=8$ GeV. It is expected that our estimations in the present work can be tested by future experiments at $\mathrm{\bar{P}ANDA}$.

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arXiv2026

$d_{N Ω}$ production in $Ωd$ scattering process

In the present work, we propose to investigate the production of $d_{N Ω}$ in the $Ω^{-} d \rightarrow p d_{N Ω}^-$ process by utilizing an effective Lagrangian approach, where $d_{N Ω}$ is identified as $NΩ$ bound state with the binding energy $E_{b}=2.46$ MeV. Experimentally, the J-PARC hadron facility proposed to investigate the $K^{-}p \rightarrow Ω^{-} \bar{K}^{(*)0} K^{+}$ process, which is expected to yield an $Ω$ beam with the momentum of approximately 3 GeV. Additionally, theoretical studies of the $ψ(2S) \rightarrow Ω^{-} \barΩ^{+}$ process at BESIII provided an $Ω$ beam with the momentum of 774 MeV. Considering these two potential $Ω$ beam sources, our estimations show that for the $Ω^{-} d \rightarrow p d_{N Ω}^-$ process, the cross sections are $\Big(329.7^{+26.9}_{-49.6}\Big)$ $μ$b, $\Big(174.0^{+26.5}_{-38.2}\Big)$ $μ$b, $\Big(16.9^{+7.4}_{-7.7}\Big)$ $μ$b, and $\Big(2.0^{+1.8}_{-1.4}\Big)$ $μ$b at $P_Ω =$ 0.7, 0.9, 2.0, and 4.0 GeV, respectively, where the central values are estimated with $Λ_{r}=1.0$ GeV, and the errors come from the variation of $Λ_{r}$ from 0.8 to 1.2 GeV. We also estimate the differential cross sections, which reach the maximum at the forward angle limit. In addition, since the $d_{N Ω}$ dibaryon predominantly decays into $ΞΛ$. Therefore, we further investigate the $Ω^{-} d \rightarrow p Ξ^- Λ$ process and estimate the relevant cross sections. It is expected that the present estimations can be tested by further experimental measurements at J-PARC and STCF in the future.

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arXiv2026

Gluon TMDs for tensor polarized deuteron in a spectator model

We present a model calculation of the transverse-momentum-dependent distributions (TMDs) for gluons in a tensor-polarized deuteron. Our model is based on the assumption that an on-shell deuteron can emit a time-like off-shell gluon, while the remaining system is treated as a single on-shell spectator particle whose mass can take on a continuous range of real values, described by a spectral function. For spin-1 hadrons, the polarization is characterized not only by a spin vector $S$ but also by a symmetric traceless spin tensor $T$. The deuteron-gluon-spectator coupling is described by an effective vertex containing three form factors. We obtain analytical expressions for thirteen T-even gluon TMDs. We also provide numerical results for the $x$-dependence and $\bm{k}_T$-dependence of these TMDs. Our analysis reveals non-negligible results of these gluon TMDs, especially for tensor-polarized hadrons, which could potentially be explored in future experimental measurements.

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arXiv2026

Production of $Ξ(1530)$ in the $K^- p$ scattering process

In the present work, we examine the production of $Ξ(1530)$ in the $K^- p \to K^{+} Ξ(1530)^{-}$ and $K^- p \to K^{0} Ξ(1530)^{0}$ reactions utilizing an effective Lagrangian approach. To accurately fit the cross sections for both processes, we include nine $Λ$ and $Σ$ hyperons and their resonances in both $s$- and $u$-channel processes. Considering the discrepancy of the measured cross sections for $K^- p \to K^+ Ξ(1530)^-$ within the range $\sqrt{s}=[2.087, 2.168]\ \mathrm{GeV}$, we employ two distinct fitting strategies: a uniform weighting scheme (model A) and a different weighting approach (model B). A comparative analysis suggests that model A yields a superior global agreement with experimental data compared to model B. Beyond fitting the cross sections, we also estimate the individual contributions from various intermediate states. Our results reveal that the cross section arising from the $Σ(1193)$ intermediate process is dominant. Furthermore, we predict different cross sections for $K^- p\to K^+Ξ(1530)^-$ and $K^- p\to K^0Ξ(1530)^0$ at several representative center-of-mass energies, providing testable predictions for forthcoming J-PARC experiments.

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arXiv2026

Dipion transitions from $X(3872)$ to $χ_{cJ}\ (J=0,1,2)$

In this work, we investigate the dipion transition processes $X(3872)\to ππχ_{cJ} (J=0,1,2)$ within the framework of heavy hadron chiral perturbation theory, treating $X(3872)$ as a molecular state composed of $D\bar{D}^*$+ H.c. components. By analyzing the box and triangle loop diagrams with the nonrelativistic effective field theory power-counting rule, we demonstrate that box diagrams dominate these dipion transition processes. Branching ratios are calculated as functions of the mixing angle $θ$, which parametrizes the neutral and charged meson compositions of the $X(3872)$. Our results indicate that the branching fractions for $X(3872)\toππχ_{c0}$, $X(3872)\to ππχ_{c1}$, and $X(3872)\to ππχ_{c2}$ are of the orders of $10^{-4}$, $10^{-3}$, and $10^{-5}$, respectively. We also predict the ratios ${\mathcal{B}[X(3872)\rightarrow ππχ_{c0/2}]}/{\mathcal{B}[X(3872)\rightarrow ππχ_{c1}]}$ and ${\mathcal{B}[X(3872)\rightarrow π^+π^-χ_{cJ}]}/{\mathcal{B}[X(3872)\rightarrow π^0π^0χ_{cJ}]}$. The latter deviates from isospin-symmetry expectations, revealing various degrees of isospin violation. By studying the $π^+π^-$ and $π^+χ_{cJ}$ invariant mass spectra, we find a double-bump structure in the $π^ + π^-$ invariant mass distributions of the process $X(3872)\to π^+π^-χ_{c1}$ and $π^+χ_{c0}$ invariant mass distribution of the process $X(3872)\to π^+π^-χ_{c0}$, which could be tested by future experimental measurements.

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arXiv2025

Systematic analysis of the transition form factors of $B_c$ to $D$-wave charmonia and corresponding semileptonic decays

In this article, the vector, axial vector and tensor form factors of $B_c$ to $D$-wave charmonia $ψ_J$ ($J=1,2,3$) and $η_{c2}$ are analyzed within the framework of three-point QCD sum rules. With the estimated vector and axial vector form factors, we study the decay widths and branching ratios of semileptonic decays $B_c\toψ_Jl\bar{ν_l}$ and $B_c\toη_{c2}l\bar{ν_l}$. Our results indicate that the semileptonic decay branching ratios of $B_c$ to $D$-wave charmonia decreases as the total angler momentum of the final state $D$-wave charmonia increases. For decay processes $B_c\to ψ_1l\barν_l$, $B_c\to ψ_2[η_{c2}]l\barν_l$ and $B_c\to ψ_3l\barν_l$, the branching ratios can reach the order $10^{-3}$, $10^{-4}$ and $10^{-5}$, respectively, which can provide a valuable reference for future experimental measurements for $B_c$ meson by LHCb collaboration. Furthermore, these results also can provide useful information to study the properties of $B_c$ meson and $D$-wave charmonia.

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arXiv2025

Analysis of the semileptonic decays $Λ_b\toΛ_cl\barν_l$ and $Ξ_b\toΞ_cl\barν_l$ in QCD sum rules

In this article, the electroweak transition form factors of $Λ_b\toΛ_c$ and $Ξ_b\toΞ_c$ are analyzed within the framework of three-point QCD sum rules. In phenomenological side, all possible couplings of interpolating current to hadronic states are considered. In QCD side, the perturbative part and the contributions of vacuum condensates up to dimension 8 are also included. With the estimated form factors, we study the decay widths and branching ratios of semileptonic decays $Λ_b\toΛ_cl\barν_l$ and $Ξ_b\toΞ_cl\barν_l$ ($l=e,μ$ and $τ$). Our results for the branching ratios of $Λ_b\toΛ_cl\barν_l$ are comparable with experimental data and the results from other collaborations. In addition, our prediction for the branching ratio of $Ξ_b\toΞ_cl\barν_l$ can provide a valuable reference for future experimental measurements.

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arXiv2025

Exploring pion emission properties of (strange) hidden-charm molecular pentaquarks in a chiral quark model

The internal structure of the exotic $P_c$ and $P_{cs}$ pentaquarks remains an open question. To address this, we demonstrate that pion emission serves as a sensitive probe by calculating its properties within a molecular scenario using the chiral quark model and coupled-channel effects. Our results reveal a strong dependence of the decay widths on the internal structure and spatial wave functions. We therefore expect this study to stimulate experimental measurements of these decays, which are crucial for determining the nature of these states and guiding the search for further molecular partners.

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arXiv2025

The $B^-\to J/ψη^\prime K^-$ reaction and the $Y(4710)$ and $K_0^*(1430)$ contributions

Motivated by the recent LHCb Collaboration analysis, we have investigated the process $B^-\to J/ψη^\prime K^-$ by considering the contributions from the resonances $Y(4710)$ and $K_0^*(1430)$. Our results are in good agreement with the measured invariant mass distributions and the Dalitz plot of LHCb, which supports the existence of the $K_0^*(1430)$ and the $Y(4710)$ in the process $B^-\to J/ψη^\prime K^-$. Since the decay mode of $Y(4710)\to J/ψη'$ is Okubo-Zweig-Iizuka (OZI) suppressed for the charmonium state, the measurements of the $\mathcal{B}(Y(4710)\to J/ψη')$ through the process $B^-\to J/ψη' K^-$ or other processes is helpful to understanding the nature of the $Y(4710)$. Thus, we advocate that Belle~II and LHCb Collaborations could perform the more precise analysis to confirm the evidence of the $Y(4710)$ state, which could be helpful to reduce the experimental uncertainties of its mass and width, and to explore its nature.

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arXiv2025

Strong decays of the $DK^\ast$ and $\bar{D}K^{\ast}$ molecular states

Inspired by the abundant structure near the threshold of the $D^{(*)}K^{(*)}/\bar{D}^{(*)}K^{(*)}$, we estimate the strong decay properties of the $T_{c\bar{s}1}^{f/a}$ and $T_{\bar{c}\bar{s}1}^{f/a}$ with $I(J^{P})=0/1(1^{+})$ in $DK^{*}$ and $\bar{D}K^{*}$ molecular scenarios in the present paper. By employing the effective Lagrangian approach, the widths of the processes $T_{c\bar{s}1}^{f}\to D^{*}K, D_{s}^{*}η, DKπ$, $T_{c\bar{s}1}^{a}\to D^{*}K, D_{s}^{*}π, DKπ$, and $T_{\bar{c}\bar{s}1}^{f/a}\to\bar{D}^{*}K, \bar{D}Kπ$ are estimated. Considering the present estimations, we propose to search for $T_{c\bar{s}1}^{f/a}$ states in $D^{*}K$ and $D_{s}^{*}π/D_{s}^{*}η$ mass invariant spectra. Their ratios may serve as an important test of the molecular scenario.

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