arXiv subjects

Fu-Lai Wang

Publications and source records attributed to Fu-Lai Wang.

At least 19 recordsLinked to original sources

arXiv2026

Possible hidden-bottom molecular pentaquarks from $P$-wave $\Lambda_bB^{()}/\Sigma_b^{()}B^{(*)}$ interactions

In this work, we perform a systematic investigation of the hidden-bottom molecular pentaquark states, encompassing both bound states and resonances, which originate from the $P$-wave interactions between ground-state bottom baryons ($\Lambda_b$, $\Sigma_b^{(*)}$) and ground-state antibottom mesons ($B^{(*)}$). Adopting the one-boson-exchange model and including the coupled-channel effects, we derive the effective potentials for all allowed quantum numbers $I(J^P) = 1/2(1/2^+)$, $1/2(3/2^+)$, $1/2(5/2^+)$, $1/2(7/2^+)$, $3/2(1/2^+)$, $3/2(3/2^+)$, $3/2(5/2^+)$, and $3/2(7/2^+)$. We then solve the coupled-channel Schr\"odinger equations to search for the bound-state solutions and perform the phase-shift analyses to identify resonance poles. Our results reveal a rich spectrum of positive-parity hidden-bottom molecular pentaquark candidates. In the isospin $I=1/2$ sector, we find several loosely bound states and associated resonances, particularly in the $\Sigma_b B^*$ and $\Sigma_b^* B^*$ channels, where the coupled-channel dynamics plays an essential role in their formation. In the isospin $I=3/2$ sector, the attraction is generally weaker because of the isospin factors. Nevertheless, we still obtain the loosely bound states and resonances, such as the $\Sigma_b^* B^*$ states with $J^P=3/2^+$, $5/2^+$, and $7/2^+$. The prominence of high-spin partial waves, for instance the $^6P_J$ components, underscores the importance of the spin-spin and tensor interactions. Our predictions provide a comprehensive and systematic spectrum of the $P$-wave hidden-bottom molecular pentaquark states and offer clear guidance for future experimental searches at LHCb and Belle~II.

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arXiv2026

Pion radiative decays of excited hidden-charm pentaquark molecules: from $\Sigma_c^{()}\bar{D}^{()}(2S)$ molecules to the reported $P_c$ states

The discovery of the hidden-charm pentaquarks $P_c(4312)$, $P_c(4440)$ and $P_c(4457)$ by the LHCb Collaboration are very likely to identify as the $\Sigma_c^{(*)}\bar{D}^{(*)}$ molecules. A natural and crucial extension is the existence of excited molecular partners built from a ground-state charmed baryon and a radially excited anti-charmed meson, namely $\Sigma_c^{(*)}\bar{D}^{(*)}(2S)$ molecules. In a framework of chiral quark model, we systematic study pion-emission decays of such excited molecules into the known ground-state $P_c$ molecules. Our results show that the decay widths are sensitive to the spin structures and the coupled-channel interferences, i.e., the $\Sigma_c\bar{D}(2S)/\Sigma_c\bar{D}^*(2S)/\Sigma_c^*\bar{D}^*(2S)[1/2(1/2^-)]$ state decays to $P_c(4440)$ with a width of several MeV, while the width to $P_c(4457)$ is suppressed below $0.3$ MeV due to destructive interference. The pion-emission decay can be the key to unveiling the excited molecular spectrum of hidden-charm pentaquarks and provides decisive experimental signatures. We expect the future experiments such as the LHCb and PANDA can verify our predictions.

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arXiv2026

Mass spectra and electromagnetic characteristics of the $K^{()}\bar D^{()}$ and $K^{()}{D}^{()}$ molecular tetraquarks from the coupled-channel dynamics

Motivated by the observation of numerous charmed-strange hadrons lying close to the $K^{(*)}\bar D^{(*)}$ and $K^{(*)}D^{(*)}$ thresholds, we systematically investigate their mass spectra and electromagnetic characteristics, explicitly incorporating the $S$-$D$ wave mixing and coupled-channel effects. For the mass spectra, we employ the one-boson-exchange model and obtain several promising $K^{(*)}\bar D^{(*)}$ and $K^{(*)}D^{(*)}$ molecular candidates awaiting future experimental confirmation. The coupled-channel dynamics is found to play an essential role: it not only enhances binding in existing channels but also generates new loosely bound states that are absent in the single-channel approximation. Regarding the electromagnetic characteristics, we discuss the M1 radiative decay widths and magnetic moments of these charmed-strange molecular tetraquarks based on our obtained mass spectra and spatial wave functions within the constituent quark model. Our results demonstrate that the electromagnetic observables serve as valuable discriminants for clarifying the nature of these hadronic molecules. We encourage experimental collaborations to focus on such predicted charmed-strange molecular tetraquark candidates, especially the genuinely exotic $K^{(*)}\bar D^{(*)}$ states comprising four different flavors with valence quark content $\bar c \bar s u d$.

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arXiv2026

Prediction of doubly-charm hadronic molecules with double strange quarks

In this work, we investigate whether the $T$-doublet charmed-strange mesons and their antiparticles can form hidden-charm hidden-strangeness molecular tetraquarks by applying the one-boson-exchange model. We identify $D_{s1}\bar D_{s1}$ ($J^{PC}=0^{++},\,1^{+-},\,2^{++}$), $D_{s1}\bar D_{s2}^*$ ($J^{PC}=1^{+\pm},\,2^{+\pm},\,3^{+\pm}$), and $D_{s2}^*\bar D_{s2}^*$ ($J^{PC}=0^{++},\,1^{+-},\,2^{++},\,3^{+-},\,4^{++}$) as promising hidden-charm hidden-strangeness molecular tetraquark candidates. Notably, the $D_{s1}\bar D_{s2}^*$ state with $J^{PC}=2^{+-}$ possesses exotic spin-parity quantum numbers forbidden for conventional mesons, providing a clean experimental signature for exotic hadrons. Moreover, the $D_{s2}^*\bar D_{s2}^*$ state with $J^{PC}=4^{++}$ is a rare high-spin hadronic molecule. We then extend the same framework to discuss the binding properties of the $T_s T_s$ systems and construct the mass spectrum of corresponding doubly-charm doubly-strangeness molecular tetraquarks. The promising candidates are $D_{s1}D_{s1}$ ($J^P=2^+$), $D_{s1}D_{s2}^*$ ($J^P=3^+$), and $D_{s2}^*D_{s2}^*$ ($J^P=4^+$), all of which are absolutely flavor-exotic. We encourage experimental searches for these predicted hadronic molecules, which would be a crucial step toward establishing doubly-charm molecular tetraquarks with strangeness $S=0$ or $2$.

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arXiv2026

Five-flavor molecular pentaquarks in the $\Xi_b^{(\prime,\,)} \bar D^{()}$ and $\Xi_c^{(\prime,\,)} B^{()}$ systems

The discovery of hidden-charm pentaquarks and open-flavor tetraquarks motivates the search for even more exotic hadron configurations. In this work, we investigate genuinely exotic molecular pentaquark candidates comprising five different flavors, focusing on the $\Xi_b^{(\prime,\,*)} \bar D^{(*)}$ and $\Xi_c^{(\prime,\,*)} B^{(*)}$ systems. Employing the one-boson-exchange model with the $S$-$D$ wave mixing and coupled-channel dynamics, we identify the most promising molecular pentaquark candidates comprising five different flavors. These include the $\Xi_b \bar D$, $\Xi_b^{\prime} \bar D$, $\Xi_c B$, and $\Xi_c^{\prime} B$ states with $I(J^P)=0(1/2^-)$, the $\Xi_b \bar D^{*}$, $\Xi_b^{\prime} \bar D^{*}$, $\Xi_c B^{*}$, and $\Xi_c^{\prime} B^{*}$ states with $I(J^P)=0(1/2^-,\,3/2^-)$, the $\Xi_b^{*} \bar D$ and $\Xi_c^{*} B$ states with $I(J^P)=0(3/2^-)$, as well as the $\Xi_b^{*} \bar D^{*}$ and $\Xi_c^{*} B^{*}$ states with $I(J^P)=0(1/2^-,\,3/2^-,\,5/2^-)$. Importantly, these loosely bound states exhibit pronounced spin splittings across different total angular momentum configurations after incorporating the spin-dependent interactions or the channel couplings. In addition, we identify several possible isovector molecular pentaquark candidates within the $\Xi_b^{(\prime,\,*)} \bar D^{(*)}$ and $\Xi_c^{(\prime,\,*)} B^{(*)}$ systems. Our predictions provide clear targets for experimental searches at facilities such as LHCb and Belle II, where the unique five-flavor quark configuration offers a distinctive experimental signature.

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arXiv2025

Electromagnetic characteristics as probes into the inner structures of the predicted $\Xi_c^{(',)}D^{()}_s$ molecular states

In this work, we conduct a systematic investigation of the electromagnetic properties, specifically the magnetic moments and the M1 radiative decay behavior, of the predicted $\Xi_c^{(',*)}D^{(*)}_s$-type double-charm hidden-strangeness molecular pentaquarks. The study is carried out within the framework of the constituent quark model to evaluate these electromagnetic observables, and our analysis incorporates three distinct scenarios: single-channel analysis, $S$-$D$ wave mixing analysis, and coupled-channel analysis. The calculated magnetic moments reveal characteristic patterns that reflect their underlying constituent configurations and provide sensitive probes for their quantum number assignments. Furthermore, we identify several M1 radiative decay channels with sizable widths that may offer promising signatures for future experimental detection. These M1 transitions also act as sensitive probes into their inner structures, displaying distinctive features that help differentiate between their constituent configurations and quantum number assignments. We anticipate that this study will stimulate experimental interest in exploring the electromagnetic properties of the $\Xi_c^{(',*)}D^{(*)}_s$ molecular states, thereby advancing our structural understanding of these exotic hadronic states.

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arXiv2025

Predicting charmed-strange molecular tetraquarks with $K^{(*)}$ and $T$-doublet charmed or anticharmed meson

In this work, we first present a systematic investigation of the $T_{\bar{c}\bar{s}}$-type charmed-strange molecular tetraquark candidates composed of a $K^{(*)}$ meson and a $T$-doublet anticharmed meson using the one-boson-exchange model, which exhibit exotic flavor content $\bar{c}\bar{s} q q$. Our results suggest that the $K^* \bar D_1$ states with $I(J^P)=0(0^-,\,1^-)$ and the $K^* \bar D_2^*$ states with $I(J^P)=0(1^-,\,2^-)$ represent the most promising candidates of the $T_{\bar{c}\bar{s}}$-type charmed-strange molecular tetraquarks, while the coupled $K \bar D_1 / K^* \bar D_1 / K^* \bar D_2^*$ system with $I(J^P)=0(1^-)$ and the coupled $K \bar D_2^* / K^* \bar D_1 / K^* \bar D_2^*$ system with $I(J^P)=0(2^-)$ can only be regarded as the possible candidates of the $T_{\bar{c}\bar{s}}$-type charmed-strange molecular tetraquarks. We further extend our analysis to the $K^{(*)} {D}_1/K^{(*)} {D}_2^*$ systems, where our results suggest a series of $T_{c \bar s}$-type charmed-strange molecular tetraquark candidates. These findings provide a comprehensive picture of the molecular spectrum in the charmed-strange tetraquark sector composed of $S$-wave kaons and (anti-)charmed mesons in the $T$-doublet and can be tested in future experimental studies.

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arXiv2025

Electromagnetic properties of possible triple-charm molecular hexaquarks

In this study, we investigate the radiative transitions of predicted triple-charm molecular hexaquarks, which play a significant role in understanding their overall spectroscopic properties. As experimentally measurable quantities, the radiative decay widths provide insights into the internal structures of these triple-charm molecular hexaquarks. Additionally, we calculate their corresponding magnetic moments, which, together with the radiative decay widths, offer a comprehensive picture of the electromagnetic properties of these exotic states. This information is valuable for guiding future experimental searches and advancing our understanding of these unique hadronic systems.

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arXiv2025

Double-bottom centrifugal-barrier molecules dancing with four quarks

Motivated by the recent Belle II measurement of the open-bottom cross section, we perform a systematic study of the double-bottom molecular tetraquark spectrum, including both $S$-wave and $P$-wave configurations. Using the one-boson-exchange potential and the complex scaling method, we investigate the $B^{(*)}\bar{B}^*$ and $B^{(*)}B^*$ systems and predict several bound states and resonances. Our analysis reveals a rich spectrum, including $B\bar{B}^*$ ($0(1^{++})$, $0(0^{-+})$), $B^*\bar{B}^*$ ($0(2^{++})$, $0(0^{-+})$, $0(1^{--})$), $BB^*$ ($0(1^+)$), and $B^*B^*$ ($0(1^+)$) bound states, as well as $B\bar{B}^*$ ($0(1^{--})$, $0(2^{--})$), $B^*\bar{B}^*$ ($0(3^{--})$), $BB^*$ ($0(0^-)$), and $B^*B^*$ ($0(1^-)$, $0(2^-)$) resonances. Our results provide theoretical support for the existence of double-bottom tetraquarks and deliver key benchmarks for future searches at LHCb, Belle II, and other experiments.

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arXiv2024

Spectroscopic Properties of Double-Strangeness Molecular Tetraquarks

Inspired by recent advances in the study of the $K^{(*)} \bar K^{(*)}$ molecular tetraquarks and the $H$-dibaryon, we focus on the spectroscopic properties of the $\bar K^{(*)} \bar K^{(*)}$ systems, which exhibit exotic flavor quantum number of $ss\bar q \bar q$. A dynamical analysis is performed using the one-boson-exchange model to describe the effective interactions for these systems, accounting for both $S$-$D$ wave mixing and coupled-channel effects. By solving the coupled-channel Schr$\ddot{\rm o}$dinger equation, we identify the $I(J^P)=0(1^+)$ $\bar K \bar K^*$ and $I(J^P)=0(1^+)$ $\bar K^* \bar K^*$ states as the most likely candidates for double-strangeness molecular tetraquarks. Furthermore, we estimate their strong decay behaviors based on the effective Lagrangian approach, with several channels exhibiting considerable decay widths. Meanwhile, we investigate their magnetic moments and M1 radiative decay widths, shedding light on their inner structures, within the constituent quark model. Finally, we encourage experimentalists to focus on these predicted double-strangeness molecular tetraquark candidates, particularly in $B$ meson decays. Such efforts could pave the way for establishing the molecular tetraquark states in the light-quark sector.

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arXiv2024

Finding Interaction Mechanism between Exotic Molecule and Conventional Hadron

An intriguing and important question arises: how do hadronic molecules interact with conventional hadrons? In this work, we propose a novel mechanism to address this issue, focusing on the interactions between hidden-charm molecular pentaquarks ($P_c$) and nucleons ($N$). By applying this mechanism, we derive the corresponding interaction potentials, enabling the prediction of the bound state properties. Our results indicate the possible existence of $P_cN$ bound states-an entirely new form of matter, ripe for exploration in the era of high-precision hadron spectroscopy. Notably, this mechanism extends beyond the $P_cN$ systems and can be applied to any hadronic molecules interacting with conventional hadrons, offering the potential for discovering a variety of novel bound states.

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arXiv2024

Exploring the mass spectrum and the electromagnetic properties of the possible $\Xi_{cc}K^{()}$ and $\Xi_{cc}\bar{K}^{()}$ molecules

Using the one-boson-exchange model, we investigate the interactions between the doubly charmed baryon $\Xi_{cc}(3621)$ and the $S-$wave (anti-)kaon accounting for the $S-D$ wave mixing and coupled-channel effects. We find the coupled $\Xi_{cc}K/\Xi_{cc}K^*$ state with $I(J^P)=0(1/2^-)$, the $\Xi_{cc}K^*$ state with $0(1/2^-)$, the $\Xi_{cc}\bar{K}$ state with $0(1/2^-)$, and the $\Xi_{cc}\bar{K}^*$ states with $0(1/2^-,3/2^-)$ can be recommended as good doubly charmed molecular candidates with strangeness $|S|=1$. We further examine their M1 radiative decay behaviors and magnetic moments within the constituent quark model framework. This information can enhance our understanding of their inner structures, including the distribution of electric charge and the orientation of the constituent quarks' spins.

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arXiv2024

The role of electromagnetic interaction in the $X(3872)$ and its analogs

We investigate the role of the electromagnetic interaction in the formation and decay of the $X(3872)$. The binding properties of the $X(3872)$ are studied by assuming the molecular nature and considering the $S$-$D$ wave mixing, isospin breaking, and coupled channel effects, and in particular the correction from the electromagnetic interaction. The radiative decays can better reflect the difference between the charged and neutral $D\bar D^*$ components, since the electromagnetic interaction explicitly breaks the isospin symmetry. We further study the radiative decay widths with the obtained wave functions for different $D\bar D^*$ channels. We also explore other similar hidden-charm molecular states. The electromagnetic interaction can make the molecule tighter. Our result of the radiative decay width for $X(3872)\rightarrow γJ/ψ$ is in agreement with the experiment. The branching ratio $R_{γψ}$ is less than 1 in our framework, which supports the Belle and BESIII measurements.

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arXiv2024

Investigating the M1 radiative decay behaviors and the magnetic moments of the predicted triple-charm molecular-type pentaquarks

In this work, we systematically study the electromagnetic properties including the M1 radiative decay widths and the magnetic moments of the isoscalar $Ξ_{c c} D^{(*)}$, $Ξ_{cc}D_{1}$, and $Ξ_{cc}D_{2}^{*}$ triple-charm molecular-type pentaquark candidates, where we adopt the constituent quark model and consider both the $S$-$D$ wave mixing effect and the coupled channel effect. Our numerical results suggest that the M1 radiative decay widths and the magnetic moments of the isoscalar $Ξ_{c c} D^{(*)}$, $Ξ_{cc}D_{1}$, and $Ξ_{cc}D_{2}^{*}$ triple-charm molecular-type pentaquark candidates can reflect their inner structures, and the study of the electromagnetic properties is the important step to construct the family of the triple-charm molecular-type pentaquarks. With the accumulation of the experimental data during the high-luminosity phase of LHC, we expect that the present work combined with the corresponding mass spectrum information can encourage the experimental colleagues at LHCb to focus on the isoscalar $Ξ_{c c} D^{(*)}$, $Ξ_{cc}D_{1}$, and $Ξ_{cc}D_{2}^{*}$ triple-charm molecular-type pentaquark candidates.

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arXiv2024

Unveiling the Composition of the Single-Charm Molecular Pentaquarks: Insights from Radiative Decay and Magnetic Moment

In order to unravel the composition of the isoscalar $DN$, $D^*N$, $D_1N$, and $D_2^*N$ molecular pentaquarks, we carry out a systematic investigation of their M1 and E1 radiative decays and magnetic moment properties. Using the constituent quark model and taking into account the $S$-$D$ wave mixing effect and the coupled channel effect, our analysis yields numerical results indicating that the M1 and E1 radiative decays and the magnetic moment properties of these molecular pentaquarks provide some insights into their inner structures. These results can provide crucial clues for distinguishing their spin-parity quantum numbers and configurations in experimental studies. In addition, we highlight the importance of the electromagnetic properties as key observables for elucidating the inner structures of the observed $\Lambda_c^{+} (2940)$ and $\Lambda_c^{+} (2910)$. We hope that these findings can inspire our experimental colleagues to further explore the family of the single-charm molecular pentaquarks and to investigate the inner structures of the $\Lambda_c^{+} (2940)$ and $\Lambda_c^{+} (2910)$ in future studies.

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arXiv2024

Surveying the mass spectra and the electromagnetic properties of the $Ξ_c^{(\prime,)} D^{()}$ molecular pentaquarks

Motivated by the observed $P_{ψs}^Λ(4459)/P_{ψs}^Λ(4338)$ and $T_{cc}(3875)^+$ states as the $Ξ_c \bar D^{*}/Ξ_c \bar D$ and $DD^{*}$ molecular candidates, respectively, in this work we investigate the $Ξ_c^{(\prime,*)} D^{(*)}$ molecular systems. We obtain the mass spectra and the corresponding spatial wave functions of the $Ξ_c^{(\prime,*)} D^{(*)}$-type double-charm molecular pentaquark candidates with single strangeness, where we utilise the one-boson-exchange model and take into account both the $S$-$D$ wave mixing effect and the coupled channel effect. Our results show that the most promising candidates of the double-charm molecular pentaquarks with single strangeness include the $Ξ_c D$ state with $I(J^P)=0(1/2^-)$, the $Ξ_c^{\prime} D$ state with $I(J^P)=0(1/2^-)$, the $Ξ_c D^{*}$ states with $I(J^P)=0(1/2^-,3/2^-)$, the $Ξ_c^{*} D$ state with $I(J^P)=0(3/2^-)$, the $Ξ_c^{\prime} D^{*}$ states with $I(J^P)=0(1/2^-,3/2^-)$, and the $Ξ_c^{*} D^{*}$ states with $I(J^P)=0(1/2^-,3/2^-,5/2^-)$. To gain further insight into the inner structures and the properties of the isoscalar $Ξ_c^{(\prime,*)} D^{(*)}$ molecular candidates, we utilize the constituent quark model to analyze their M1 radiative decay behaviors and magnetic moments based on the obtained mass spectra and spatial wave functions, which can offer the significant information to determine their spin-parity quantum numbers and configurations in the forthcoming experiments. We suggest that our experimental colleagues search for the predicted $Ξ_c^{(\prime,*)} D^{(*)}$ molecular states.

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arXiv2023

Probing exotic $J^{PC}$ resonances from deeply bound charmoniumlike molecules: Insights for identifying exotic hadrons

We investigate the resonance phenomenon in deeply bound charmoniumlike states. By interpreting the $Y(4220)$, $Y(4360)$, and $\psi(4415)$ states as deeply $S$-wave bound $D \bar D_1$, $D^* \bar D_1$, and $D^* \bar D_2^*$ molecules, respectively, we robustly predict the existence of $4$ $S$-wave deeply bound $C$-parity partner states and $13$ $P$-wave charmoniumlike molecular resonances. These states, formed by exchanging the light mesons and pinpointed through the complex scaling method, include $3$ $S$-wave bound states with exotic quantum numbers $I(J^{PC})$= $0(1^{-+})$ and $5$ $P$-wave resonances with exotic $0(0^{-+})$ and $0(2^{+-})$. We expect future experiments to search for such exotic molecular resonances, which will not only enrich the ongoing construction of ``Particle Zoo 2.0" but also help to scrutinize the hadronic molecular assignments of the $Y$-family particles including the $Y(4220)$, $Y(4360)$, and $\psi(4415)$ states.

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arXiv2023

New type of doubly charmed molecular pentaquarks containing most strange quarks: Mass spectra, radiative decays, and magnetic moments

In this work, we first predict the mass spectra of the $Ω_{c}^{(*)}{D}_s^{(*)}$-type doubly charmed molecular pentaquark candidates, where the one-boson-exchange model is adopted by considering both the $S$-$D$ wave mixing effect and the coupled channel effect. Our findings indicate that the $Ω_{c}{D}_s^*$ state with $J^P={1}/{2}^{-}$, the $Ω_{c}^*{D}_s^*$ state with $J^P={1}/{2}^{-}$, and the $Ω_{c}^*{D}_s^*$ state with $J^P={3}/{2}^{-}$ can be considered as the most promising doubly charmed molecular pentaquark candidates, and the $Ω_{c}{D}_s$ state with $J^P={1}/{2}^{-}$, the $Ω_{c}^*{D}_s$ state with $J^P={3}/{2}^{-}$, and the $Ω_{c}{D}_s^*$ state with $J^P={3}/{2}^{-}$ are the possible doubly charmed molecular pentaquark candidates. Furthermore, we further explore the radiative decays and the magnetic moments of the most promising doubly charmed molecular pentaquark candidates in the constituent quark model. As a crucial aspect of spectroscopy, the information of the radiative decays and the magnetic moments can provide the valuable clues to reflect their inner structures. With the accumulation of higher statistical data at the Large Hadron Collider, we propose that the LHCb Collaboration should focus on the problem of searching for these predicted doubly charmed molecular pentaquark candidates containing most strange quarks in the coming years.

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