arXiv subjects

Xinmei Zhu

Publications and source records attributed to Xinmei Zhu.

At least 19 recordsLinked to original sources

arXiv2026

Systematic study of baryon-baryon interactions in singly bottomed systems

In this work, we systematically investigate the baryon-baryon interactions in singly bottomed dibaryon systems within the chiral quark model and search for possible bound states. By exploring the baryon-baryon interaction, we find that low-isospin channels tend to generate deeper attractive interactions and are prone to form bound states. We also find that decuplet-decuplet systems tend to show stronger attraction and support a larger number of bound states, whereas octet-octet systems generally exhibit weaker attraction and fewer bound solutions. The binding behavior of octet-decuplet systems generall lies between these two cases. Several bound states are obtained, which are $ΔΣ_b^*$ with $IJ=\frac{1}{2}0$, $\frac{1}{2}1$, $\frac{1}{2}2$, $\frac{1}{2}3$, and $\frac{3}{2}3$, the $ΔΣ_b$ with $IJ=\frac{1}{2}1$, $\frac{1}{2}2$, $\frac{3}{2}1$, and $\frac{3}{2}2$, the $NΣ_b^*$ with $IJ=\frac{1}{2}2$, the $ΣΣ_b$ with $IJ=00$, $01$, and $11$, the $ΣΣ_b^*$ with $IJ=01$ and $02$, the $Σ^*Σ_b$ with $IJ=01$ and $02$, and the $Σ^*Σ_b^*$ with $IJ=00$, $01$, $02$, $03$, and $13$. Further investigations of the corresponding scattering processes are still required to determine whether these bound-state candidates can be identified. These states deserve further experimental investigation.

hep-ph↗

arXiv2026

Investigation of deuteron-like singly bottomed dibaryon resonances

We perform a systematical investigation of the existence of the deuteron-like singly bottomed dibaryon resonance states with strangeness $S=-1,~-3,~-5$ in the chiral quark model. Two resonance states with strangeness $S=-1$ are obtained in the baryon-baryon scattering process. The first candidate is $ΣΣ_b$ in the $ΛΛ_b$ and $NΞ_b^*$ scattering process, with the resonance energy 6974.22 MeV - 6975.37 MeV and the decay width 14.450 MeV, respectively; the other one is $ΣΣ_b^*$ in the $NΞ_b$ and $NΞ'_b$ scattering process, with the resonance energy 6990.69 MeV - 7008.37 MeV and the decay width 43.790 MeV, respectively. The Root Mean Square (RMS) radius calculation shows that the former tends to be in a compact structure, while the latter tends to be in a molecular structure. Both of these resonance states are worthy of experimental exploration. Furthermore, it should be emphasized that the effect of channel-coupling is of great importance in exploring exotic hadron states, and investigating the scattering process may serve as an effective approach to identifying genuine resonances.

hep-ph↗

arXiv2025

Multibaryon states in the framework of an equivparticle model

Within the framework of an equivparticle model employing mean-field approximation, we investigate systematically the mass spectra of color-singlet $N$-quark configurations with $N = 3, 6, 9, 12, 15$, and 18, which are assumed to be spherically symmetric with quarks occupying the 1s$_{1/2}$ state, i.e., compact multibaryon states. At a given quark number $N$, these states collectively form a single irreducible representation under SU(6) symmetry. Our analysis yields comprehensive mass formulae that characterize these SU(6) multiplets, providing a unified description of their mass spectra. In order to effectively constrain the parameter space of the model and improve the prediction accuracy, we carry out a Bayesian parameter inference based on the experimental masses of eight baryons and $D_{03}$. The posterior probability density functions and their correlations of the model parameters are examined, based on which we further predict the masses of various multibaryon states and provide their 68$\%$ and 90$\%$ credible intervals. In our prediction, H-dibaryon, $D_{03}$, and the dibaryon with $S = -6$ are all bound states relative to $ΛΛ$, $ΔΔ$ and $ΩΩ$ thresholds, while slight probabilities of other stable dibaryons (23.64$\%$ more stable than $Ω^- Ξ^0$ for the state wtih $I = \frac{1}{2}$, $S = -5$ and 92.49$\%$ more stable than $Ξ^0Ξ^-$ for the state wtih $I = 0$, $S = -4$) and tribaryons (0.25$\%$ more stable than $Ξ^-Ξ^0Ξ^0$ for the state wtih $S = -6$, $I = 1/2$; 2.19$\%$ more stable than $ΛΞ^0Ξ^-$ for the state wtih $S = -5$, $I = 0$; and 2.21$\%$ more stable than $ΛΛΞ^0$ for the state wtih $S = -4$, $I = 1/2$) are observed as well. For heavier compact multibaryon states, it is unlikely for them to be stable.

hep-ph↗

arXiv2025

Search for doubly charmed dibaryons in baryon-baryon scattering

We perform a systematical investigation of the doubly charmed dibaryon system with quantum numbers $IJ=01$, and strangeness numbers $S=0$, $-2$ and $-4$ in the framework of the chiral quark model. Two resonance states with strangeness numbers $S=-2$ is obtained in the $ΛΩ_{cc}$ scattering channel, which are $Ξ_{cc}^{\ast}Ξ$ with resonance mass 5081 MeV and decay width 0.3 MeV, and the $Ξ_{c}Ξ_{c}^{\ast}$ state with the mass 5213 MeV and decay width 19.8 MeV, respectively. These two predicted charmed dibaryon candidates are worth searching for experimentally. Besides, we would like to emphasize that the multi-channel coupling calculation is important to confirm the existence of multiquark states. The coupling can shift the energy of the resonance, give the width to the resonance and even destroy the resonance. Therefore, to provide the necessary information for experiments to search for exotic hadron states, the coupling calculation between the bound channels and open channels is indispensable.

hep-ph↗

arXiv2024

Search for singly charmed dibaryons in baryon-baryon scattering

We perform a systematical investigation of the singly charmed dibaryon system with strangeness numbers $S=-1$, $-3$ and $-5$ in the framework of the chiral quark model. Two resonance states with strangeness numbers $S=-1$ are obtained in the baryon-baryon scattering process. In the $ΛΛ_{c}$ scattering phase shifts, the $ΣΣ_{c}$ appears as a resonance state with the mass and width 3591 MeV and 11.1 MeV, respectively. In the $NΞ_{c}$ and $NΞ^{\prime}_{c}$ scattering phase shifts, the $ΣΣ^{\ast}_{c}$ exhibits as a resonance state with the mass and width 3621-3624 MeV and 14.9 MeV, respectively. All these heavy-flavor dibaryons are worth searching for in experiments. Besides, we would like to emphasize that the coupling calculation between the bound channels and open channels is indispensable. The study of the scattering process maybe an effective way to look for the genuine resonances.

hep-ph↗

arXiv2024

Investigating $Ξ$ resonances from pentaquark perspective

We have investigated the $qss\bar{q}q$ ($q = u$ or $d$) system to find possible pentaquark explanations for the $Ξ$ resonances. The bound state calculation is carried out within the framework of the quark delocalization color screening model. The scattering processes are also studied to examine the possible resonance states. The current results indicate that the $Ξ(1950)$ can be interpreted as $Λ\bar{K}^*$ state with $J^P = 1/2^-$. Three states are identified that match the $Ξ(2250)$, which are $Σ^* \bar{K}^*$ state with $J^P = 3/2^-$, $Σ^* \bar{K}^*$ state with $J^P =5/2^-$, and $Ξ^* ρ$ state with $J^P =5/2^-$. This may explain the conflicting experimental values for the width of the $Ξ(2250)$. A new $Ξ$ resonance is predicted, whose mass and width are 2066--2079 MeV and 186--189 MeV, respectively. These results contribute to understanding the nature of the $Ξ$ resonances and to the future search for new $Ξ$ resonances. Moreover, it is meaningful to further investigate the $Ξ$ resonances from an unquenched picture on the basis of pentaquark investigation.

hep-ph↗

arXiv2023

Prediction of $P_{cc}$ states in quark model

Inspired by the observation of hidden-charm pentaquark $P_c$ and $P_{cs}$ states by the LHCb Collaboration, we explore the $qqc\bar{c}c$ ($q~=~u$ or $d$) pentaquark systems in the quark delocalization color screening model. The interaction between baryons and mesons and the influence of channel coupling are studied in this work. Three compact $qqc\bar{c}c$ pentaquark states are obtained, whose masses are 5259 MeV with $I(J^P)$ = $0(1/2^-)$, 5396 MeV with $I(J^P)$ = $1(1/2^-)$, and 5465 MeV with $I(J^P)$ = $1(3/2^-)$. Two molecular states are obtained, which are $I(J^P)$ = $0(1/2^-)$ $Λ_c J/ψ$ with 5367 MeV and $I(J^P)$ = $0(5/2^-)$ $Ξ_{cc}^* \bar{D}^*$ with 5690 MeV. These predicted states may provide important information for future experimental search.

hep-ph↗

arXiv2023

Exotic $Qq\bar{q}\bar{q}$ states in the chiral quark model

In the framework of the chiral quark model, we investigate the $Qq\bar{q}\bar{q}$ ($Q= c, b$ and $q= u, d$) tetraquark system with two structures: $Q\bar{q}$-$q\bar{q}$ and $Qq$-$\bar{q}\bar{q}$. The bound-state calculation shows that for the single channel, there is no evidence for any bound state below the minimum threshold in both $cq\bar{q}\bar{q}$ and $bq\bar{q}\bar{q}$ systems. However, after coupling all channels of two structures, we obtain a bound state below the minimum threshold in the $cq\bar{q}\bar{q}$ system with the energy of $1998$ MeV, and the quantum number is $IJ^{P}=\frac{1}{2}0^{+}$. Meanwhile, in the $bq\bar{q}\bar{q}$ system, two bound states with energies of $5414$ MeV and $5456$ MeV are obtained, and the quantum numbers are $IJ^{P}=\frac{1}{2}0^{+}$ and $IJ^{P}=\frac{1}{2}1^{+}$, respectively. Besides, we also employe the real-scaling method to search for resonance states in the $cq\bar{q}\bar{q}$ and $bq\bar{q}\bar{q}$ systems. Unfortunately, no genuine resonance states were obtained in both systems. We suggest future experiments to search for these three possible bound states.

hep-ph↗

arXiv2023

Is $d^*(2380)$ a compact hexaquark state?

The most fascinating dibaryon in the non-strange quark sector is $d^*(2380)$, which was reported by WASA-at-COSY Collaboration and confirmed by A2@MAMI Collaboration. The reported mass and width are $M\approx2.37$ GeV, $Γ\approx70$ MeV and the quantum numbers $IJ^P=03^+$. The structure of $d^*(2380)$ is still in controversy. In the present calculation, the powerful method in few-body system, Gaussian expansion method is employed to explore the structure of $d^*(2380)$ in the framework of constituent quark models without assuming the presupposed structure. The results show that the radius of $d^*(2380)$ is around 0.7 fm, a very compact object. Because of the compact structure, the color singlet-singlet component has a large overlap with the color octet-octet one, two colorless, large overlapped $Δ$s dominate the state is possible.

hep-ph↗

arXiv2023

Prediction of charmed-bottom pentaquarks in quark model

Inspired by the fully heavy tetraquark states reported by the LHCb, ATLAS and CMS Collaborations, we perform a systemical investigation of the low-lying fully heavy pentaquark systems composed of charm and bottom quarks (anti-quark) in the chiral quark model. With the help of the channel-coupling, we obtain several fully heavy pentaquark candidates, which are $cccc\bar{b}$ and $bbbb\bar{c}$ systems with $J^P = 1/2^-$ and $3/2^-$, $cccb\bar{c}$, $bbbc\bar{b}$, $cccb\bar{b}$ and $bbbc\bar{c}$ systems with $J^P = 5/2^-$. The binding energies of these states are all below 10 MeV and the root mean square (RMS) are around 1.8 fm, which indicates that these states are likely to be molecular states. These predicted exotic states may provide new ideas for experimental searches and we expect more experimental and theoretical researches to study and understand the fully heavy states in future.

hep-ph↗

arXiv2021

Investigation of meson-meson interaction

In the framework of the quark delocalization color screening model, we investigate the meson-meson interaction in the fully light four-quark system . The calculation of the effective potentials of all the $S-$wave states shows that for most states the interaction between two vector mesons is attractive; the one between a pseudoscalar meson and a vector meson is repulsive or weakly attractive; and the one between two pseudoscalar mesons is always repulsive. However, there is still some exception. The interaction of the $IJ=00$ $ππ$ channel is attractive, while the one of the $IJ=02$ $ϕϕ$ channel is repulsive. So it is difficult to use the $S-$wave $ϕϕ$ state to explain the $X(2239)$ at present calculation. The $S-$wave $ρρ$ states are more likely to be resonance states, which are worthy of investigating in future work. The study of the contribution of each interaction term shows that both the one-gluon exchange and the kinetic energy interaction are important in the interaction between two mesons. The study of the variation of the delocalization parameter indicates that the contribution of the kinetic energy relates to the intermediate-range attraction mechanism in QDCSM, which is achieved by the quark delocalization.

hep-ph↗

arXiv2021

Search for doubly-heavy dibaryons in the quark-delocalization color-screening model

We perform a systemical investigation of the low-lying doubly-heavy dibaryon systems with strange $S=0$, isospin $I=0$, $1$, $2$ and the angular momentum $J=0$, $1$, $2$, $3$ in the quark delocalization color screening model. We find the effect of channel-coupling cannot be neglected in the study of the multi-quark systems. Due to the heavy flavor symmetry, the results of the doubly-charm and doubly-bottom dibaryon systems are similar with each other. Both of them have three bound states, the quantum numbers of which are $IJ=00$, $IJ=02$ and $IJ=13$, respectively. The energies are $4554$ MeV, $4741$ MeV, and $4969$ MeV respectively for the doubly-charm systems and $11219$ MeV, $11416$ MeV, and $11633$ MeV respectively for the doubly-bottom dibaryon systems. Besides, six resonance states are obtained, which are $IJ=00$ $NΞ_{cc}$ and $NΞ_{bb}$ with resonance mass of $4716$ MeV and $11411$ MeV respectively, $IJ=11$ $NΞ^*_{cc}$ and $NΞ^*_{bb}$ with resonance mass of $4757$ MeV and $11432$ MeV respectively, and $IJ=12$ $Σ_{c}Σ^*_{c}$ and $Σ_{b}Σ^*_{b}$ with resonance mass of $4949$ MeV and $11626$ MeV respectively. All these heavy dibaryons are worth searching for on experiments, although it will be a challenging work.

hep-ph↗

arXiv2021

The explanation of some exotic states in the $cs\bar{c}\bar{s}$ tetraquark system

Inspired by the recent observation of $χ_{c0}(3930)$, $X(4685)$ and $X(4630)$ by the LHCb Collaboration and some exotic resonances such as $X(4350)$, $X(4500)$, etc. by several experiment collaborations, the $cs\bar{c}\bar{s}$ tetraquark systems with $IJ^{P}=00^+$, $01^+$ and $02^+$ are systematically investigated in the framework of the quark delocalization color screening model(QDCSM). Two structures, the meson-meson and diquark-antidiquark structures, as well as the channel-coupling of all channels of these two configurations are considered in this work. The numerical results indicate that the molecular bound state $\bar{D}_{s}D_{s}$ with $IJ^{P}=00^+$ can be supposed to explain the $χ_{c0}(3930)$. Besides, by using the stabilization method, several resonant states are obtained. There are four $IJ^{P}=00^{+}$ states around the resonance mass 4035 MeV, 4385 MeV, 4524 MeV, and 4632 MeV, respectively; one $IJ^{P}=01^{+}$ state around the resonance mass 4327 MeV; and two $IJ^{P}=02^{+}$ states around the resonance mass 4419 MeV and 4526 MeV, respectively. All of them are compact tetraquarks. Among these states, $X(4350)$, $X(4500)$ and $X(4700)$ can be explained as the compact tetraquark state with $IJ^{P}=00^{+}$, and the $X(4274)$ is possible to be a candidate of the compact tetraquark state with $IJ^{P}=01^{+}$. More experimental tests are expected to check the existence of all these possible resonance states.

hep-ph↗

arXiv2020

Full heavy dibaryons

The existence of full heavy dibaryons $Ω_{ccc}Ω_{bbb}$, $Ω_{ccc}Ω_{ccc}$ and $Ω_{bbb}Ω_{bbb}$ with $J=0,~1,~2,~3$ and $P=\pm1$ are investigated in the framework of a constituent quark model. The dibaryon composed of six $c$ or $b$ quarks with $J^{P}=0^{+}$ is possible to be bound, while the dibaryon with the $cccbbb$ configuration is difficult to form any bound state. We also study the interaction between two full heavy baryons, and the effective potentials, suggesting the existence of dibaryons $Ω_{ccc}Ω_{ccc}$ and $Ω_{bbb}Ω_{bbb}$, and the absence of binding for $Ω_{ccc}Ω_{bbb}$ system. Besides, the calculation of the low-energy scattering phase shifts of the $Ω_{ccc}Ω_{ccc}$ and $Ω_{bbb}Ω_{bbb}$, as well as the scattering length also confirm the existence of stable full heavy dibaryons $Ω_{ccc}Ω_{ccc}$ and $Ω_{bbb}Ω_{bbb}$.

hep-ph↗

arXiv2020

Are $N\barΩ$ bound states?

Inspired by the progress of the experimental search of the $NΩ$ dibaryon by the STAR collaboration, we study $N\barΩ$ systems in the framework of quark delocalization color screening model. Our results show that the attraction between $N$ and $\barΩ$ is a little bit larger than that between $N$ and $Ω$, which indicates that it is more possible for the $N\barΩ$ than the $NΩ$ system to form bound states. The dynamic calculations state that both the $J^{P}=1^{+}$ and $2^{+}$ $N\barΩ$ systems are bound states. The binding energy of these two states are deeper than that of $NΩ$ systems with $J^{P}=2^{+}$, and the $NΩ$ system with $J^{P}=1^{+}$ is unbound. The calculation of the low-energy scattering phase shifts, scattering length and the effective range also supports the existence of the $N\barΩ$ bound states with $J^{P}=1^{+}$ and $2^{+}$. So the $N\barΩ$ states are better hexaquark states and stronger signals are expected in experiments.

nucl-th↗

arXiv2019

Reanalysis of the most strange dibaryon within constituent quark models

The most strange dibaryon $ΩΩ$ with quantum numbers $S=-6$, $I=0$, and $J^{P}=0^{+},~1^{-},~2^{+},~3^{-}$ is reanalyzed in the framework of quark delocalization color screening model (QDCSM) and chiral quark model (ChQM). The $ΩΩ$ dibaryon with $J^{P}=0^{+}$ is bound, and the one with other quantum numbers $J^{P}=1^{-},~2^{+},~3^{-}$ are all unbound in our calculation. The low-energy scattering phase shifts, the scattering length, and the effective range of the $ΩΩ$ dibaryon with $J^{P}=0^{+}$ also support the existence of such strange dibaryon. This dibaryon is showed to be a shallow bound state in QDCSM, while the binding energy becomes much larger in the ChQM by including the effect of the hidden-color channel coupling. And the scalar nonet meson-exchange in the ChQM also provides more attraction for the $ΩΩ$ system. Experimental search for such most strange dibaryon will provide much information for understanding the hadron-hadron interactions in different quark models.

hep-ph↗

arXiv2019

Pion-induced production of hidden-charm pentaquarks $P_{c}(4312),P_{c}(4440)$, and $P_{c}(4457)$

The production of the hidden-charm pentaquarks $P_{c}$ via pion-induced reaction on a proton target is investigated within an effective Lagrangian approach. Three experimentally observed states, $P_c(4312)$, $P_c(4440)$, and $P_c(4457)$, are considered in the calculation, and the Reggeized $t$-channel meson exchange is considered as main background for the reaction $π^{-}p\rightarrow J/ψn$. The numerical results show that the experimental data of the total cross section of the reaction $π^{-}p\rightarrow J/ψn$ at $W\simeq 5$ GeV can be well explained by contribution of the Reggeized $t$ channel with reasonable cutoff. If the branching ratios $Br[P_{c}\rightarrow J/ψN]\simeq 3\%$ and $Br[P_{c}\rightarrow πN]\simeq 0.05\%$ are taken, the average value of the cross section from the $P_{c}(4312)$ contribution is about 1.2 nb/100 MeV, which is consistent with existing rude data at near-threshold energies. The results indicate that the branching ratios of the $P_{c}$ states to the $J/ψN$ and $πN$ should be small. The shape of differential cross sections shows that the Reggeized $t$-channel provides a sharp increase at extreme forward angles, while the differential cross sections from the $P_{c}$ states contributions are relatively flat. High-precision experimental measurements on the reaction $π^{-}p\rightarrow J/ψn$ at near-threshold energies are suggested to confirm the LHCb hidden-charm pentaquarks as genuine states, and such experiments are also helpful to understand the origin of these resonance structures.

hep-ph↗

arXiv2018

Hidden-strange molecular states and the $Nϕ$ bound state via a QCD van der Waals force

In this work, we study the hidden-strange molecular states composed of a baryon and a vector meson in a coupled-channel $Nρ-Nω-Nϕ-ΛK^*-ΣK^*$ interaction. With the help of the effective Lagrangians which coupling constants are determined by the SU(3) symmetry, the interaction is constructed and inserted into the quasipotential Bethe-Salpeter equation to search for poles in the complex plane, which correspond to molecular states. Two poles are found with a spin parity $3/2^-$ near the $Nρ$ and the $ΣK^*$ thresholds, which can be related to the $N(1700)$ and the $N(2100)$, respectively. No pole near the $Nϕ$ threshold can be found if direct interaction between a nucleon and $ϕ$ meson is neglected according to the OZI rule. After introducing the QCD van der Waals force between a nucleon and $ϕ$ meson, a narrow state can be produced near the $Nϕ$ threshold. Inclusion of the QCD van der Waals force changes the line shape of the invariant mass spectrum in the $Nϕ$ channel leading to a worse agreement with the present low-precision data. Future experiments at BelleII, JLab, and other facilities will be very helpful to clarify the existence of these possible hidden-strange molecular states.

hep-ph↗