arXiv subjects

Yu-Shuai Li

Publications and source records attributed to Yu-Shuai Li.

16 recordsLinked to original sources

arXiv2026

Systematic exploration of triply heavy tetraquarks: spectroscopic and decay characteristics

While hidden, singly, doubly, and fully heavy tetraquark states have been experimentally observed, triply heavy tetraquark states remain experimentally unconfirmed. We systematically investigate the spectroscopic and decay properties of four triply heavy-flavor tetraquark systems ($cc\bar{c}\bar{n}$, $cc\bar{c}\bar{s}$, $bb\bar{b}\bar{n}$, $bb\bar{b}\bar{s}$; $n=u,d$) based on the nonrelativistic quark model. Using an effective Hamiltonian, we employ the Gaussian expansion method to solve the four-body Schr\"{o}dinger equation and incorporate the effect of color-spin configuration mixing. Results show both $cc\bar{c}\bar{q}$ and $bb\bar{b}\bar{q}$ systems have two $J^{P}=0^{+}$, three $J^{P}=1^{+}$, and one $J^{P}=2^{+}$ states, with ground-state masses of 5.2-5.5 GeV and 15.0-15.3 GeV, respectively. Root-mean-square radius analysis supports compact tetraquark configurations. All states are unstable, with rearrangement strong decays dominant and negligible radiative decays. Narrow resonances (e.g., $T_{c^{2}\bar{c}\bar{s}}(5360,0^{+})$, $T_{b^{2}\bar{b}\bar{n}}(15148,2^{+})$) arise from Feynman amplitude cancellation. We propose experimental searches in $J/\psi D^{*}_{s}$/ $\eta_{c}D_{s}$ (5.3-5.4 GeV) and $\Upsilon B^{*}$ (15.1-15.2 GeV) channels, providing key guidance for triply heavy tetraquark identification.

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arXiv2025

The nonleptonic decays of double-charmed baryon $\Omega_{cc}^{+}$ within the nonrelativistic quark model

In this work, we investigate the two-body nonleptonic decays of double-charmed baryon $\Omega_{cc}^{+}$ within a nonrelativistic quark model, in which the nonfactorizable amplitudes contributed by $W$-exchange diagrams are evaluated under pole model assumption. To reduce sensitivity of decay amplitudes to arbitrary choice of baryon wave functions, we adopted charmed baryon wave functions obtained by solving the Schr\"{o}dinger equation with a nonrelativistic quark potential model. Our results show that the branching fractions of CF decays $\Omega_{cc}^{+}\to\Omega_{c}^{0}\pi^{+}$ and $\Xi_{c}^{(\prime)+}\pi^{+}$, as well as the SCS decays $\Omega_{cc}^{+}\to\Omega_{c}^{0}K^{+}$, $\Sigma_{cc}^{++}K^{-}$, $\Xi_{c}^{\prime+}\eta$ and $\Lambda_{c}^{+}\bar{K}^{0}$ can reach up to a few percents. Particularly for the $\Omega_{cc}^{+}\to\Omega_{c}^{0}K^{+}$ mode, owing to the large factorizable amplitude and constructive pole contributions, the branching fraction is comparable to CF decays. These decay modes can serve as the discovery channels for the double-charmed baryon $\Omega_{cc}^{+}$ in future experiments like LHCb and Belle II.

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arXiv2025

Systematic investigation of the spectroscopy and decay behaviors of doubly-charmed pentaquarks

Building upon the discoveries of the $Ξ^{++}_{cc}(3621)$ and $T^{+}_{cc}(3875)$, we undertake a comprehensive investigation into the mass spectra, internal structures, and decay properties of doubly-charmed pentaquarks. By treating the two light quarks as a tightly bound diquark, the five-body system reduces to a four-body heavy quark-heavy quark-diquark-antiquark configuration. Within the constituent quark model framework, we calculate their mass spectra in the range of 4.7-5.4 GeV and corresponding internal mass contributions via the Gaussian expansion method. The root-mean-square radii, typically between 1.1-1.6 fm, indicate compact spatial structures. Furthermore, we also calculate the rearrangement decay widths via the quark-interchange model, finding that all states are unstable and decay into a singly-charmed baryon and a singly-charmed meson. Several narrow resonances have been identified, some of which have a total width even below 10 MeV. We hope that our study could provide valuable guidance for future theoretical investigations and experimental searches targeting doubly-charmed pentaquarks.

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arXiv2025

The nonleptonic decays $Ξ_{cc}^{++}\toΞ_{c}^{(\prime)+}π^{+}$ within the nonrelativistic quark model

In this work, we study the nonleptonic decays $Ξ_{cc}^{++}\toΞ_{c}^{(\prime)+}π^{+}$ with considering $Ξ_{c}-Ξ_{c}^{\prime}$ mixing. The relevant decay amplitudes are evaluated within the framework of nonrelativistic quark model, combining the baryon spatial wave functions adopted from solving the Schrödinger equation with a nonrelativistic potential. With the mixing angle ranging $θ\in(-18.2^{\circ},-14.3^{\circ})$, we successfully reproduce the measured ratio $R=\mathcal{B}[Ξ_{cc}^{++}\toΞ_{c}^{\prime+}π^{+}]/\mathcal{B}[Ξ_{cc}^{++}\toΞ_{c}^{+}π^{+}]$ reported by the LHCb Collaboration. Furthermore, we estimate the branching fractions as $\mathcal{B}[Ξ_{cc}^{++}\toΞ_{c}^{+}π^{+}]=(3.2\sim4.3)\%$ and $\mathcal{B}[Ξ_{cc}^{++}\toΞ_{c}^{\prime+}π^{+}]=(4.2\sim6.0)\%$, and the asymmetry parameters as $α[Ξ_{cc}^{++}\toΞ_{c}^{+}π^{+}]=(-0.80\sim-0.81)$ and $α[Ξ_{cc}^{++}\toΞ_{c}^{\prime+}π^{+}]=(-0.61\sim-0.62)$. The measurements of absolute branching fractions and asymmetry parameters by the ongoing LHCb and Belle II experiments will be helpful for further testing our numerical results and confirming the mixing angle.

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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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arXiv2025

Revisiting heavy-flavor conserving weak decays of charmed baryons within the nonrelativistic quark model

In this work, we investigate the heavy-flavor conserving weak decays of charmed baryons, specifically the processes $Ξ_{c} \to Λ_{c} π$ and $Ω_{c} \to Ξ_{c} π$, where the pole model is employed to account for the nonfactorizable contributions. Additionally, the nonperturbative parameters involved are determined within the framework of the nonrelativistic quark model, utilizing exact baryon wave functions obtained by solving the Schrödinger equation with a nonrelativistic potential. By considering the mixing angle $θ\in (24.4^\circ, 32.4^\circ)$ for $Ξ_{c}-Ξ_{c}^{\prime}$ mixing, we find that the experimental data can be effectively reproduced. Furthermore, we estimate the branching ratios: $\mathcal{B}(Ξ_{c}^{+} \to Λ_{c}^{+} π^{0}) = (8.69 \sim 9.79) \times 10^{-3}$, $\mathcal{B}(Ω_{c}^{0} \to Ξ_{c}^{+} π^{-}) = (11.3 \sim 12.1) \times 10^{-3}$, and $\mathcal{B}(Ω_{c}^{0} \to Ξ_{c}^{+} π^{0}) = (4.67 \sim 5.23) \times 10^{-3}$. These predictions can be tested in ongoing experiments at LHCb, Belle II, and BESIII.

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arXiv2023

Angular distribution of the FCNC process $B_{c}\to{D}_{s}^{*}(\to{D}_{s}π)\ell^{+}\ell^{-}$

In this work, we study the flavor-changing neutral-current process $B_{c}\to{D}_{s}^{*}(\to{D}_{s}π)\ell^{+}\ell^{-}$ ($\ell$= $e$, $μ$, $τ$). The relevant weak transition form factors are obtained by using the covariant light-front quark model, in which, the main inputs, i.e., the meson wave functions of $B_{c}$ and $D_{s}^{*}$, are adopted as the numerical wave functions from the solution of the Schrödinger equation with the modified Godfrey-Isgur model. With the obtained form factors, we further investigate the relevant branching fractions and their ratios, and some angular observables, i.e., the forward-backward asymmetry $A_{FB}$, the polarization fractions $F_{L(T)}$, and the $CP$-averaged angular coefficients $S_{i}$ and the $CP$ asymmetry coefficients $A_{i}$. We also present our results of the clean angular observables $P_{1,2,3}$ and $P^{\prime}_{4,5,6,8}$, which can reduce the uncertainties from the form factors. Our results show that the corresponding branching fractions of the electron or muon channels can reach up to $10^{-8}$. With more data being accumulated in the LHCb experiment, our results are helpful for exploring this process, and deepen our understanding of the physics around the $b\to{s}\ell^{+}\ell^{-}$ process.

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arXiv2023

Spectroscopic survey of higher-lying states of $B_c$ meson family

In this work, we investigate the spectroscopy of higher $B_c$ mesons, with a special focus on the consideration of the unquenched effects. To account for such effects, we employ the modified Godfrey-Isgur model and introduce a screening potential. The resulting mass spectrum of the concerned higher $B_c$ states is then presented, showing significant deviations after considering the unquenched effects. This emphasizes the importance of considering the unquenched effects when studying of the higher $B_c$ mesons. Furthermore, we determine the corresponding spatial wave functions of these $B_c$ mesons, which have practical applications in subsequent studies of their decays. These decays include two-body Okuba-Zweig-Iizuka allowed strong decays, dipion transitions between $B_c$ mesons, radiative decays, and some typical weak decays. With the ongoing high-luminosity upgrade of the Large Hadron Collider, we expect the discovery of additional $B_c$ states in the near future. The knowledge gained from the mass spectrum and the different decay modes will undoubtedly provide valuable insights for future experimental explorations of these higher $B_c$ mesons.

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arXiv2023

Transition form factors and angular distributions of the $\bm{Λ_b\toΛ(1520)(\to N\bar{K})\ell^+\ell^-}$ decay supported by baryon spectroscopy

We calculate the weak transition form factors of the $Λ_b\toΛ(1520)$ transition, and further calculate the angular distributions of the rare decays $Λ_b\toΛ(1520)(\to N\bar{K})\ell^{+}\ell^{-}$ ($N\bar{K}=\{pK^-,n\bar{K}^0\}$) with unpolarized $Λ_b$ and massive leptons. The form factors are calculated by the three-body light-front quark model with the support of numerical wave functions of $Λ_b$ and $Λ(1520)$ from solving the semirelativistic potential model associated with the Gaussian expansion method. By fitting the mass spectrum of the observed single bottom and charmed baryons, the parameters of the potential model are fixed, so this strategy can avoid the uncertainties arising from the choice of a simple harmonic oscillator wave function of the baryons. With more data accumulated in the LHCb experiment, our result can help for exploring the $Λ_b\toΛ(1520)\ell^+\ell^-$ decay and deepen our understanding on the $b\to s\ell^+\ell^-$ processes.

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arXiv2023

Investigating the transition form factors of $Λ_b\toΛ_c(2625)$ and $Ξ_b\toΞ_c(2815)$ and the corresponding weak decays with support from baryon spectroscopy

We calculate the form factors of the $Λ_b\toΛ_c(2625)$ and $Ξ_b\toΞ_c(2815)$ transitions, and additionally evaluate the corresponding semileptonic decays and the color-allowed two-body nonleptonic decays. In order to obtain the concerned form factors, we use the three-body light-front quark model with the support from baryon spectroscopy. In this work, as important physical inputs, the spatial wave functions of concerned baryons are obtained by the Gaussian expansion method with a semirelativistic potential model. For the semileptonic processes, the branching ratios of the electron and muon channels can reach up to the order of magnitude of $1\%$, where our result $\mathcal{B}(Λ_b^0\toΛ_c^+(2625)μ^-ν_μ)=(1.641\pm0.113)\%$ is consistent with the current experimental data. As for the nonleptonic processes, the decays to $π^-$, $ρ^-$, and $D_s^{(*)-}$ final states have considerable widths. These discussed decay modes could be accessible at the LHCb experiment.

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arXiv2022

Investigating the $\mathbf{Υ(10753)\to Υ(1^3D_J)η}$ transitions

In this work, we investigate the $Υ(10753)\toΥ(1^3D_J)η$ ($J=1,2,3$) processes, where the $Υ(10753)$ is assigned as a conventional bottomonium under the $4S$-$3D$ mixing scheme. Our result shows that the concerned processes have considerable branching ratios, {\it i.e.}, branching ratios $\mathcal{B}[Υ(10753)\toΥ(1^3D_{1})η]$ and $\mathcal{B}[Υ(10753)\toΥ(1^3D_{2})η]$ can reach up to the order of magnitude of $10^{-4}-10^{-3}$, while $\mathcal{B}[Υ(10753)\toΥ(1^3D_{3})η]$ is around $10^{-6}-10^{-5}$. With the running of Belle II, it is a good opportunity for finding out the concerned hidden-bottom hadronic decays.

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arXiv2022

$\mathbf{Υ(10753)\toΥ(nS)π^+π^-}$ decays induced by hadronic loop mechanism

In this work, we investigate the $Υ(10753)\toΥ(nS)π^+π^-$ ($n=1,2,3$) processes by considering the hadronic loop mechanism, where $Υ(10753)$ is assigned to a conventional bottomonium in the $4S$-$3D$ mixing scheme. Our results of the concerned processes own considerable branching ratios, which can reach up to the order of magnitude of $10^{-4}-10^{-3}$. We should indicate that the measured $Γ_{e^+e^-}\times\mathcal{B}[Υ(10753)\toΥ(nS)π^+π^-]$ values given by Belle can be reproduced well. This fact supports the former bottomonium assignment to the $Υ(10753)$ in the $4S$-$3D$ mixing scheme. Obviously, it is a good opportunity for the ongoing Belle II experiment if the predicted result in this work can be tested further.

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arXiv2022

Restudy of the color-allowed two-body nonleptonic decay of bottom baryons ${Ξ_b}$ and ${Ω_b}$ supported by hadron spectroscopy

In this work, we calculate the branching ratios of the color-allowed two-body nonleptonic decays of the bottom baryons, which include the $Ξ_b\to Ξ_c^{(*)}$ and $Ω_b\to Ω_c^{(*)}$ weak transitions by emitting a pseudoscalar meson ($π^{-}$, $K^{-}$, $D^{-}$, and $D_s^{-}$) or a vector meson ($ρ^{-}$, $K^{*-}$, $D^{*-}$, and $D_s^{*-}$). For achieving this aim, we adopt the three-body light-front quark model with the support of hadron spectroscopy, where the spatial wave functions of these heavy baryons involved in these weak decays are obtained by a semirelativistic potential model associated with the Gaussian expansion method. Our results show that these decays with the $π^-$, $ρ^-$, and $D_s^{(*)-}$-emitted mode have considerable widths, which could be accessible at the ongoing LHCb and Belle II experiments.

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arXiv2021

Role of the newly measured $B\to KD\bar{D}$ process to establish $χ_{c0}(2P)$ state

In this work, the branching ratio $\mathcal{B}[B\to Kχ_{c0}(2P)]$ is extracted for the first time through the fit fractions in the newly measured $B\to KD\bar{D}$ process by LHCb. With the rescattering mechanism, this extracted branching ratio is reproduced well. Our study further enforces the role of the newly measured $B\to KD\bar{D}$ process to establish the $χ_{c0}(2P)$ charmonium state, which is a crucial step when constructing charmonium family.

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arXiv2021

Hidden-bottom hadronic decays of $Υ(10753)$ with a $η^{(\prime)}$ or $ω$ emission

In this work, we propose the $4S$-$3D$ mixing scheme to assign the $Υ(10753)$ into the conventional bottomonium family. Under this interpretation, we further study its hidden-bottom hadronic decays with a $η^{(\prime)}$ or $ω$ emission, which include $Υ(10753)\toΥ(1S)η^{(\prime)}$, $Υ(10753)\to h_{b}(1P)η$ and $Υ(10753)\toχ_{bJ}ω$ ($J$=0,1,2) processes. Since the $Υ(10753)$ is above the $B\bar{B}$ threshold, the coupled-channel effect cannot be ignored, thus, when calculating partial decay widths of these $Υ(10753)$ hidden-bottom decays, we apply the hadronic loop mechanism. Our result shows that these discussed decay processes own considerable branching fractions with the order of magnitude of $10^{-4}\sim 10^{-3}$, which can be accessible at Belle II and other future experiments.

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arXiv2021

Revisiting semileptonic decays of $Λ_{b(c)}$ supported by baryon spectroscopy

The semileptonic decays of $Λ_{b}\toΛ_{c}^{(*)}\ellν_\ell$ and $Λ_{c}\toΛ^{(*)}\ellν_\ell$ are studied in the light-front quark model in this work. Instead of the quark-diquark approximation, we use the three-body wave functions obtained by baryon spectroscopy. The ground states $(1/2^{+})$, the $λ$-mode orbital excited states $(1/2^{-})$, and the first radial excited states $(1/2^{+})$ of $Λ_{(c)}^{(*)}$ are considered. The discussions are given for the form factors, partial widths, branching fractions, leptonic forward-backward asymmetries, hadron polarizations, lepton polarizations, and the lepton flavor universalities. Our results are useful for the inputs of heavy baryon decays and understanding the baryon structures, and helpful for experimental measurements.

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