arXiv subjects

Zhong-Yu Wang

Publications and source records attributed to Zhong-Yu Wang.

14 recordsLinked to original sources

arXiv2026

Revealing dipion correlations for the observed substructure near the $π^+π^-$ mass threshold in $ψ(3686)\to J/ψπ^+π^-$

Based on the world's largest $ψ(3686)$ data sample, the BESIII Collaboration recently reported a substructure near the $π^+π^-$ mass threshold in the decay $ψ(3686) \to J/ψπ^+π^-$, challenging the established understanding of the dipion invariant mass spectrum. We propose that this substructure arises directly from dipion correlations. Using a chiral unitary approach, we successfully reproduce the observed anomaly, thereby providing strong evidence of dipion correlation in heavy quarkonium decays. This approach also allows us to predict the corresponding dipion correlation function.

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arXiv2025

Prediction of $QQqq\bar{s}$ molecular pentaquarks within the extended local hidden gauge approach

We investigate hadronic molecular states with the quark contents $ccqq\bar{s}$, $bbqq\bar{s}$, and $bcqq\bar{s}$ $(q=u,d)$ by employing the extended local hidden gauge approach. Considering that the $S$-wave meson-baryon interactions are dominated by vector meson exchange, the coupled channels scattering amplitudes are obtained by solving the Bethe-Salpeter equation in its on-shell form. We find that the poles appearing on the complex Riemann sheet are potential candidates for dynamically generated molecular pentaquark states. The results suggest the existence of a total of fourteen molecular states with quantum numbers $I(J^{P})=0(1/2^{-})$, $0(3/2^{-})$, and $0(5/2^{-})$, which arise from the interactions of the $K^{(*)}Ξ_{cc}^{(*)}$, $K^{(*)}Ξ_{bb}^{(*)}$, $K^{(*)}Ξ_{bc}^{(*)}$, and $K^{(*)}Ξ_{bc}^{'}$ channels, respectively. Their binding energies are calculated to be about $0.1-33$ MeV, and this range depends on the free parameter of the theory. Our research contributes to the spectroscopic studies of hadronic molecular pentaquark states.

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arXiv2025

Scalar resonance contributions in the $D_{s1}(2460)^{+} \rightarrow D_{s}^{+}π^{+}π^{-}$ reaction

Inspired by the newly observed $T_{c\bar{s}}$ state in the $D_{s1}(2460)^{+} \rightarrow D_{s}^{+}π^{+}π^{-}$ reaction by the LHCb Collaboration, we investigate the amplitude of this decay to explore the origins and properties of the open-charm tetraquark state based on the final state interaction. The invariant mass distributions of $D_{s}^{+}π^{+}$ and $π^{+}π^{-}$ are well reproduced by the $S$-wave scattering amplitudes of the coupled channel systems $D_{s}π$ and $ππ$. However, neither the tree-level nor both the tree-level and $ππ$ coupled channel scattering contributions can describe the experimental data well, which indicates that the $D_{s}π$ coupled channel scattering is required. We find that the $T_{c\bar{s}}$ and $f_{0}(500)$ resonances are dynamically generated from the pseudoscalar-pseudoscalar meson interaction within the chiral unitary approach. In addition, we find the corresponding poles and also calculate the $S$-wave scattering length for the $DK$ channel, which is on the same scale as the result extracted from the experiment. We propose that the $T_{c\bar{s}}$ and $f_{0}(500)$ resonances in the $D_{s1}(2460)^{+} \rightarrow D_{s}^{+}π^{+}π^{-}$ reaction are hadronic molecular type particles.

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arXiv2024

Roles of $f_{0}(500)$ and $f_{0}(980)$ in the $D_{(s)}^{+}\rightarrowπ^{+}π^{+}π^{-}$ decays

With the recent measurements of the $D_{s}^{+}\rightarrow π^{+}π^{+}π^{-}$ and $D^{+}\rightarrow π^{+}π^{+}π^{-}$ decays by the LHCb Collaboration, we study these two decay processes by considering the final state interaction formalism. Taking into account the external and internal $W$-emission dominant mechanisms at the quark level, our model can naturally explain why the $D_{s}^{+}$ decay only has a contribution from the $f_{0}(980)$ resonance, while the $D^{+}$ decay has contributions from both the $f_{0}(500)$ and $f_{0}(980)$ states. The magnitudes and phases of $π^{+}π^{-}$ for $S$-wave amplitudes in our model are in agreement with the experimental measurements. These results support the interpretations of $f_{0}(500)$ and $f_{0}(980)$ as the $ππ$ and $K\bar{K}$ resonances, respectively, where they are dynamically generated from the $S$-wave pseudoscalar-pseudoscalar meson interactions within the chiral unitary approach.

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arXiv2024

Possible molecules of triple-heavy pentaquarks within the extended local hidden gauge formalism

In this study, we explore the interactions between mesons and baryons in the open heavy sectors to identify potential triple-heavy molecular pentaquarks. We derive the meson-baryon interaction potentials using the vector meson exchange mechanism within the extended local hidden gauge formalism. The scattering amplitudes are computed by solving the coupled-channel Bethe-Salpeter equation, revealing several bound systems. By analyzing the poles of these amplitudes in the complex plane, we determine the masses and widths of these bound states. Additionally, we evaluate the couplings and compositeness of different channels within each bound system to assess their molecular characteristics. Our predictions include four $Ω_{ccc}$-like states, four $Ω_{bbb}$-like states, fourteen $Ω_{bcc}$-like states, and ten $Ω_{bbc}$-like states, which could be targets for future experimental investigations.

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arXiv2024

Molecular-type $QQss\bar{s}$ pentaquarks predicted by an extended hidden gauge symmetry approach

In this work, we investigate the double-heavy molecular pentaquark states with the quark contents $ccss\bar{s}$, $bbss\bar{s}$, and $bcss\bar{s}$ by using the coupled channel approach. The extended local hidden gauge Lagrangians are used to obtain the meson-baryon interactions by exchanging the vector mesons. We predict some candidates for the molecular states with the quantum numbers $I(J^{P}) = 0(1/2^{-}, 3/2^{-}, 5/2^{-})$, whose binding energies are of the order of $20-30$ MeV and whose widths are all less than $8$ MeV. These predicted exotic double-heavy molecular pentaquark states may be accessible in future experiments such as LHCb.

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arXiv2023

The hidden strange $B_{c}$-like molecular states

With the chiral unitary approach, we evaluate the hidden strange $B_{c}$-like molecular states of $b\bar{c}s\bar{s}$ systems $\bar{B}_{s}\bar{D}_{s}$, $\bar{B}_{s}^{*}\bar{D}_{s}$, $\bar{B}_{s}\bar{D}_{s}^{*}$, and $\bar{B}_{s}^{*}\bar{D}_{s}^{*}$ coupled to the non-strange channels. The $S$-wave scattering amplitudes are calculated based on the vector meson exchange, four pseudoscalar mesons contact interactions, and four vector mesons contact interactions obtained from the extended local hidden gauge approach. We find six states below the threshold of the most relevant channel. The binding energies of these states are around $1-10$ MeV and the widths are around $0.2-0.7$ MeV. Our research is a supplement to the mass spectra of $B_{c}$-like states, which may be useful for the experimental search in the future.

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arXiv2023

Are the $a_{0}(1710)$ or $a_{0}(1817)$ resonances in the $D_{s}^{+} \rightarrow K_{S}^{0}K^{+}π^{0}$ decay?

The BESIII Collaboration claimed that a new $a_{0}(1817)$ resonance was found in the recent results of the $D_{s}^{+} \rightarrow K_{S}^{0}K^{+}π^{0}$ decay. For this decay process, we perform a unitary amplitude to analyze the contributions of the states $a_{0}(980)^{+}$ and $a_{0}(1710)^{+}$ with the final state interactions. Considering the Cabibbo-favored external and internal $W$-emission mechanisms at the quark level, and the contributions of the resonances $a_{0}(980)^{+}$, $a_{0}(1710)^{+}$ in the $S$-wave and $\bar{K}^{*}(892)^{0}$, ${K}^{*}(892)^{+}$ in the $P$-wave, the recent experimental data of the $K_{S}^{0}K^{+}$ invariant mass spectrum from the BESIII Collaboration can be described well. In our results, the states $a_{0}(980)$ and $a_{0}(1710)$ are dynamically generated from the final state interactions of $K\bar{K}$ and $K^{*}\bar{K}^{*}$, respectively, which support the molecular nature for them. Moreover, some obtained branching fractions are in agreement with the experimental measurements.

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arXiv2022

Study of the resonance contributions in the $Ξ_{b}^{-} \rightarrow pK^{-}K^{-}$ decay

The decay process $Ξ_{b}^{-} \rightarrow pK^{-}K^{-}$ is studied with the final state interaction approach by considering the contributions from the $S$-wave meson-baryon interactions, and also the intermediate state $Λ(1520)$ in the $D$-wave. The low-lying resonances $Λ(1405)$ and $Λ(1670)$ have significant contributions, which are both dynamically generated from the $S$-wave final state interactions with isospin $I=0$. Furthermore, the $Λ(1520)$ state also has important contributions from $D$-wave. With these resonances contributions, the experimental data of the lower $pK^{-}$ invariant mass distributions are well described. We also discuss the contribution of another resonance in the $S$-wave with isospoin $I=1$, which cannot be ignored. Moreover, some of the branching fractions obtained for the corresponding decay channels are consistent with the experimental measurements.

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arXiv2021

Study of pion vector form factor and its contribution to the muon $(g-2)$

In the present work, we investigate several theoretical models of the pion vector form factor and aim at getting the best fit for the two-pion cross sections to reduce the uncertainties of the calculation of two-pion contribution to the muon anomalous magnetic moment. Combined with a polynomial description to the pion vector form factor, we obtain the best fit from the Gounaris-Sakurai (or Kühn-Santamaria) model for the experimental data up to 1 GeV. By product, the branching ratio of $ω\to ππ$ can be extracted as $\text{Br}(ω\toππ)=(1.52\pm 0.06) \%$, which is consistent with the one of Particle Data Group. With the best fit of the data, we obtain the muon anomalous magnetic moment from two-pion contribution as $a_μ^{\mathrm{HVP,\; LO}}(π^{+} π^{-} \leq 1\ \text{GeV}) = (497.76\pm3.15) \times 10^{-10}$. Our results are consistent with the other works.

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arXiv2021

Scalar resonances in the final state interactions of the decays $D^{0} \rightarrow π^{0}π^{0}π^{0}, π^{0}π^{0}η,π^{0}ηη$

We investigate the scalar resonances in the processes of $D^{0} \rightarrow π^{0}π^{0}π^{0}, π^{0}π^{0}η, π^{0}ηη$ decays based on the chiral unitary approach for the final state interaction. We start from singly Cabibbo-suppressed production diagrams which provide a primary quark pair to hadronize two pseudoscalar mesons in $D^{0}$ decays. The resonances $f_{0}(500)$, $f_{0}(980)$ and $a_{0}(980)$ are dynamically produced from the final state interactions of the meson pairs. In our results, the experimental data for the $π^{0}η$ invariant mass spectrum of the $D^{0} \rightarrow π^{0}ηη$ decay can be described well. We also make the predictions for the $π^{0}π^{0}$ invariant mass spectrum of the $D^{0} \rightarrow π^{0}π^{0}π^{0}$, where the $f_{0}(980)$ can be found, and for the $π^{0}π^{0}$, $π^{0}η$ invariant mass spectrum of the $D^{0} \rightarrow π^{0}π^{0}η$, where the $f_{0}(500)$, $f_{0}(980)$ and $a_{0}(980)$ appear. Furthermore, the branching ratios of each decay channel are predicted. We expect more accurate measurements of these decays to better understand the nature of the states $f_{0}(500)$, $f_{0}(980)$ and $a_{0}(980)$.

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arXiv2021

Study of $D_{s}^{+} \rightarrow K^{+} K^{-} π^{+}$ decay

We investigate the $D_{s}^{+} \rightarrow K^{+} K^{-} π^{+}$ decay theoretically with the final state interactions, which is based on the chiral unitary approach and takes into account the external and internal $W$-emission mechanisms at the quark level. Only considering three resonances contributions, the $f_0(980)$ in $S$-wave, the $\bar {K}^{*}(892)^{0}$ and $ϕ(1020)$ in $P$-wave, one can make a good description of the recent experimental data from BESIII Collaboration, where the contribution from $S$-wave is found to be small. Besides, we also make a calculation of the corresponding branching fractions, which are consistent with the results of BESIII Collaboration and Particle Data Group.

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arXiv2021

Is two-poles' $Λ(1405)$ one state or two?

To understand the nature of two poles for the $Λ(1405)$ state, we revisit the interactions of $\bar{K}N$ and $πΣ$ with their coupled channels, where two-poles structure is found in the second Riemann sheet. We also dynamically generate two poles in the single channel interaction of $\bar{K}N$ and $πΣ$, respectively. Moreover, we make a further study of two poles' properties by evaluating the couplings, the compositeness, the wave functions, and the radii for the interactions of four coupled channels, two coupled channels and the single channel. Our results show that the nature of two poles is unique. The higher-mass pole is a pure $\bar{K} N$ molecule, and the lower-mass one is a compositeness of mainly $πΣ$ with tiny component $\bar{K} N$. From our results, one can conclude that the $Λ(1405)$ state would be overlapped with two different states of the same quantum number.

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arXiv2020

Study $B^{0}_{(s)}$ decays into $ϕ$ and a scalar or vector meson

In the present work, we investigate the decays of $B^{0}_{s} \rightarrow ϕπ^{+}π^{-}$ and $B^{0} \rightarrow ϕπ^{+}π^{-}$ with the final state interactions based on the chiral unitary approach. In the final state interactions of the $π^+π^-$ with its coupled channels, we study the effects of the $ηη$ channel in the two-body interactions for the reproduction of the $f_{0}(980)$ state. Our results for the $π^+π^-$ invariant mass distributions of the decay $B^{0}_{s} \rightarrow ϕπ^{+}π^{-}$ describe the experimental data up to 1 GeV well, with the resonance contributions from the $f_{0}(980)$ and $ρ$. For the predicted invariant mass distributions of the $B^{0} \rightarrow ϕπ^{+}π^{-}$ decay, we found that the contributions from the $f_{0}(500)$ are significant except for the ones from the $f_{0}(980)$ state. With some experimental branching ratios as input to determine the production vertex factors, we make some predictions for the branching ratios of the other final decay channels, including the vector mesons, in the $B^0_{(s)}$ decays, where some of them are consistent with the experimental ones within the uncertainties.

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