arXiv subjects

Hui-Hua Zhong

Publications and source records attributed to Hui-Hua Zhong.

6 recordsLinked to original sources

arXiv2026

$Ω_c$ baryon spectrum and strong decays in a constituent quark model

In this work, we study the $Ω_c$ baryon spectrum up to the $2P$ excitations within a semi-relativistic constituent quark potential model, where the mixing between different configurations with the same spin-parity numbers is dynamically considered. Furthermore, the strong decay properties for the excited $Ω_c$ states are evaluated within an improved chiral quark model by including the relativistic correction term. In a unified framework, we provide a reasonable explanation of the widths, masses, and mass splittings, for the newly observed $Ω_c$ resonances $Ω_c(3000)$, $Ω_c(3050)$, $Ω_c(3065)$, $Ω_c(3090)$, $Ω_c(3120)$, $Ω_c(3185)$, and $Ω_c(3327)$. It is found that the configuration mixing is crucial for understanding the strong decay properties and mass splittings, while the relativistic correction term of the strong transition operator plays an important role in the states dominated by the radial excitations. We expect our study can provide useful references for establishing a more abundant $Ω_c$ spectrum.

hep-ph↗

arXiv2026

Probing the inner structures of the observed $Ξ_b$ and $Ξ_b'$ resonances

To shed light on the inner structure of the observed single-bottom strange baryons, in this work we systematically study the Okubo-Zweig-Iizuka allowed strong decay properties of $1P$- and $2S$-wave $Ξ_b$ and $Ξ_b'$ baryons within the $j-j$ coupling scheme in the framework of the quark pair creation model. For a comparison, we also give the predictions of the chiral quark model. The calculations indicate that: (i) The $1P$-wave $λ$-mode $Ξ_b$ states $Ξ_b|J^P=1/2^-,1\rangle_λ$ and $Ξ_b|J^P=3/2^-,1\rangle_λ$ are highly promising candidates for the observed state $Ξ_b(6087)$ and $Ξ_b(6095)/Ξ_b(6100)$, respectively. The $1P$-wave $ρ$-mode $Ξ_b$ states $Ξ_b|J^P=3/2^-,2\rangle_ρ$ and $Ξ_b|J^P=5/2^-,2\rangle_ρ$ are likely candidates for the state $Ξ_b(6227)$. Meanwhile, we cannot rule out the possibility that $Ξ_b(6227)$ could be a candidate of the $1P$-wave $λ$-mode $Ξ_b'$ state $Ξ_b'|J^P=3/2^-,2\rangle_λ$ or $Ξ_b'|J^P=5/2^-,2\rangle_λ$. (ii) For the other $1P$-wave $ρ$-mode $Ξ_b$ states and $1P$-wave $λ$-mode $Ξ_b'$ states, they may be moderate states with a width of several tens of MeV. Their main decay channels are $Ξ_bπ$, $Ξ_b'π$, $Ξ_b^*π$ or $Λ_b\bar{K}$. The width of the $1P$-wave $ρ$-mode $Ξ_b'$ states are slightly broader, approximately several tens to over one hundred MeV, and the dominant decay channels are $Ξ_b'π$, $Ξ_b^*π$, $Σ_bK$ or $Σ_b^*K$. (iii) The $2S$-wave $λ$-mode $Ξ_b$ and $Ξ_b'$ states are most likely to be relatively narrow state with a width of only a few to around ten MeV, and they mainly decay into $Ξ_b'π$ or $Ξ_b^*π$. In addition, the $2S$-wave $λ$-mode $Ξ_b'$ states may also mainly decay into the $1P$-wave $Ξ_b$ baryon via the pionic decay processes.

hep-ph↗

arXiv2026

Understanding the 1P- and 2S-wave nucleon resonances within the extended Lee-Friedrichs Model

We present a unified desciption of the low-lying $1P$- and $2S$-wave nucleon resonance within the framework of an extended Lee-Friedrichs scheme. By incorporating the coupled-channel dynamics between bare quark-model states and the $πN$, $πΔ$ and $ηN$ meson-baryon continua, we examine the mass shifts and structural properties of these excited states. We demonstrate that when the model parameters are calibrated to match the $1P$-wave spectrum and their widths, the pole associated with the bare $2S$ state is naturally shifted downward to the mass region of physical Roper resonance--$N(1440)$, thereby offering a dynamical explanation for the long-standing level-inversion problem. An approximate analysis of compositeness and elementariness reveals that the Roper resonance contains a significant meson-baryon continuum states, consistent with the picture of a bare core heavily dressed by meson-baryon cloud. Simultaneously, the pole positions and properties of five $1P$-wave resonances--$N(1535)$, $N(1650)$, $N(1520)$, $N(1700)$ and $N(1675)$ are successfully reproduced. Our results highlight the essential role of coupled-channel effects in shaping the nucleon spectrum and provide a consistent microscopic insight into the interplay between internal quark degrees of freedom and external hadronic fields.

hep-ph↗

arXiv2024

Unified study of nucleon and $Δ$ baryon spectra and their strong decays with chiral dynamics

In this work we systematically study both the mass spectra and strong decays of the nucleon and $Δ$ resonances up to the $N=2$ shell within a unified quark model framework with chiral dynamics. In this framework we achieve a good description of the strong decay properties of the well-established nucleon and $Δ$ resonances. Meanwhile, the mass reversal between $N(1440)1/2^{+}$ as the first radial excitation state and the $1P$-wave nucleon resonances can be explained. We show that the three-body spin-orbit potential arising from the one-gluon exchange can cause a large configuration mixing between $N(1520)3/2^-$ and $N(1700)3/2^-$, and is also responsible for the large splitting between $Δ(1600)1/2^-$ and $Δ(1700)3/2^-$. Some of these baryon resonances turn to weakly couple to the $Nπ$, $Nη$, $KΛ$, and $KΣ$ channels, which may answer the question why they have not been established in these channels via the $πN$ and $γN$ scatterings. It shows that these ``missing resonances" may have large potentials to be established in the $Nππ$ final state due to their large decay rates into either the $Δ(1232)$ or $1P$-wave nucleon resonances via the pionic decays. Further experimental search for their signals in charmonium decays at BESIII is thus strongly recommended.

hep-ph↗

arXiv2024

Running Coupling and Running Quark Mass Effects on the Elastic Form Factors of Nucleons

We study the elastic electric and magnetic form factors of the proton, neutron and the charged roper resonance ($G_E^p$, $G_M^p$, $G_E^n$, $G_M^n$, $G_E^R$ and $G_M^R$) systematically in a constituent quark model. Three ingredients are crucial in this study: i) the mixing between the pure S-wave and other components which produces a nonzero neutron electric form factor. ii) a running coupling constant that soften the form factors. iii) the running quark mass function, $M_q(p^2)$, which is responsible for the decreasing of the $μ_p G_E^p(Q^2)/G_M^p(Q^2)$ as $Q^2$ increases. The produced elastic form factors of the proton and neutron match the corresponding observed values fairly well. Our study shows that $μ_p G_E^p(Q^2)/G_M^p(Q^2) \approx M_q(Q^2/9)/M_q(0)$ upto $Q^2 \approx 4 \text{ GeV}^2$. We give predictions on the elastic form factors of the roper resonance, the electric charge and the magnetic momentum radius ratios of the roper resonance to the proton are $r^R_{E}/r^p_{E} \approx r^R_{M}/r^p_{M} \approx 1.5$.

hep-ph↗

arXiv2022

Further understanding the nature of $Ω(2012)$ within a chiral quark model

In our previous works, we have analyzed the two-body strong decays of the low-lying $Ω$ baryon states within a chiral quark model. The results show that the $Ω(2012)$ resonance favors the three-quark state with $J^P=3/2^-$ classified in the quark model. With this assignment, in the present work we further study the three-body strong decay $Ω(2012)\to Ξ^*(1530)\bar{K} \to Ξπ\bar{K}$ and coupled-channel effects on $Ω(2012)$ from nearby channels $Ξ\bar{K}$, $Ωη$ and $Ξ^*(1530)\bar{K}$ within the chiral quark model as well. It is found that the $Ω(2012)$ resonance has a sizeable decay rate into the three-body final state $Ξπ\bar{K}$. The predicted ratio $R_{Ξ\bar{K}}^{Ξπ\bar{K}}=\mathcal{B}[Ω(2012)\to Ξ^*(1530)\bar{K}\to Ξπ\bar{K}]/\mathcal{B}[Ω(2012)\to Ξ\bar{K}]\simeq 12\%$ is close to the up limit $11\%$ measured by the Belle Collaboration in 2019, however, our predicted ratio is too small to be comparable with the recent data $0.97\pm 0.31$. Furthermore, our results show that the coupled-channel effects on the $Ω(2012)$ is not large, its components should be dominated by the bare three-quark state, while the proportion of the molecular components is only $\sim 16\%$. To clarify the nature of $Ω(2012)$, the ratio $R_{Ξ\bar{K}}^{Ξπ\bar{K}}$ is expected to be tested by other experiments.

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