arXiv subjects

Qiang Zhao

Publications and source records attributed to Qiang Zhao.

At least 19 recordsLinked to original sources

arXiv2026

Fully charmed tetraquarks on the Lattice with controlled errors

We introduce the lattice quark potential model (LQPM), which discretizes the nonrelativistic quark potential model on a periodic cubic lattice and diagonalizes the resulting many-body Hamiltonian exactly. Unlike variational approaches, which provide only upper bounds on the energy, LQPM removes this variational bias, and its remaining finite-volume uncertainty is removed by extrapolation. Formulated directly in coordinate space, the method is indifferent to the specific form of the potential and accommodates arbitrary interactions, such as including three-body forces and spin-orbit and tensor couplings, that are difficult to treat in conventional few-body approaches. As a benchmark, the charmonium and $Ω_{ccc}$ spectra are reproduced within a few MeV of experiment. For the fully charmed tetraquark $cc\bar{c}\bar{c}$, we obtain three resonances $J^P = 0^+, 1^+,$ and $2^+$ ground states above the $η_c η_c$, $η_c J/ψ$, $J/ψJ/ψ$ thresholds, respectively. Our results establish exact lattice diagonalization as a controlled, systematically improvable, and broadly applicable route to multiquark spectroscopy, providing a quantitative benchmark for the strong interaction and valuable guidance for future experimental searches for exotic hadrons.

hep-ph↗

arXiv2026

SAGE: Saliency-Annealed Gated Encoder for Universal Vision Recognition

When adapting self-supervised Vision Transformers (ViTs) to dense prediction, existing methods often treat the ViT as a passive feature extractor and may underuse the rich priors encoded in its representations, including saliency, global context, and high-frequency details. We propose SAGE (Saliency-Annealed Gated Encoder), an enhanced ViT-Adapter backbone that explicitly exploits these priors through three complementary innovations: (1) a saliency-guided architecture that extracts DINO-style class-token (CLS) saliency to guide feature gating and high-frequency enhancement, together with dynamic multi-layer aggregation and a local-detail branch; (2) an annealing-based training paradigm designed to improve convergence and feature quality during early training while reducing feature drift later in training; and (3) a two-stage, quality-aware training mechanism that smoothly transitions from focal loss to Varifocal Loss (VFL) within a single training run. Across the evaluated tasks (Fig.~\ref{fig:fig_com}), SAGE achieves state-of-the-art (SOTA) or competitive results on COCO (62.8 box AP and 55.3 mask AP), COCO keypoint estimation (78.5 AP), ADE20K (60.3 mIoU for semantic segmentation and 44.9 mask AP for instance segmentation), TinyImageNet classification (94.76\% Top-1 accuracy), and DIOR-R oriented object detection (78.8 AP$_{50}$). The same backbone is used across tasks, with task-specific decoders. To the best of our knowledge, SAGE is the first framework to achieve multi-task state-of-the-art results on Huawei Ascend NPUs. Code and pretrained models will be released after internal review.

cs.CV↗

arXiv2026

Probing the two-pole structure of the $D_0^*(2300)$ with an $SU(3)$ flavor filter

We propose an $SU(3)$ flavor-filtering strategy to resolve the two-pole structure associated with the $D_0^*(2300)$ and to probe its flavor-sextet component directly in invariant-mass distributions. In unitarized chiral dynamics, the two poles originate predominantly from different irreducible representations of the coupled $\mathcal{D}Φ$ system. We show that the strong decays $Υ\to\barΞ_{c}^{(\prime)}Λ(1520)\mathcal{D}Φ$ and the weak decays $Ξ_{b}^{(\prime)}\toπ^-Λ(1520)\mathcal{D}Φ$ provide approximately antitriplet- and sextet-selective production sources. The predicted $Dπ$, $Dη$, and $D_s\bar K$ spectra exhibit complementary signatures: the higher pole near $2.45~\mathrm{GeV}$ generates a characteristic enhancement between the $Dη$ and $D_s\bar K$ thresholds and a pronounced near-threshold structure in the sextet-favored channels, whereas the lower pole near $2.1~\mathrm{GeV}$ dominates the antitriplet-favored channels. The contrast between these line shapes directly reflects the flavor representation selected by the corresponding cascade-baryon tag. The $Υ$ modes therefore provide experimentally testable observables for establishing the two-pole nature of the $D_0^*(2300)$ and for identifying a charmed-meson resonance with a dominant flavor-sextet component, while the weak-decay analysis tests the robustness of the line-shape pattern against changes in the production mechanism.

hep-ph↗

arXiv2026

Nuclear mass table in deformed relativistic Hartree-Bogoliubov theory in continuum, III: nuclei with $8 \leq Z \leq 120$

The mass table in the deformed relativistic Hartree-Bogoliubov theory in continuum (DRHBc) with the PC-PK1 density functional has been established for nuclei with $8 \leq Z \leq 120$, extended from the previous works for even-even nuclei [Zhang et al. (DRHBc mass table collaboration), At. Data Nucl. Data Tables 144, 101488 (2022)] and for even-$Z$ nuclei [Guo et al. (DRHBc mass table collaboration), At. Data Nucl. Data Tables 158, 101661 (2024)]. The calculated binding energies, two- and one-nucleon separation energies, root-mean-square (rms) radii of neutron, proton, matter, and charge distributions, quadrupole deformations, neutron and proton Fermi surfaces, and the blocked neutron (proton) orbitals of odd-$N$ ($Z$) nuclei are tabulated and compared with the available experimental data. A total of 9495 nuclei are predicted to be bound, with an rms deviation of 1.444 MeV from the 2380 mass data. Good agreement with the available experimental pairing gaps, $α$ decay energies, and charge radii is also achieved. The accuracies of the calculated nuclear masses and nucleon separation energies as well as the prediction for drip lines are compared with those obtained by other relativistic and nonrelativistic density functional calculations. It turns out that the DRHBc theory with PC-PK1 provides one of the best microscopic descriptions for nuclear masses. The systematics of nucleon separation energies, pairing gaps, pairing energies, two-nucleon gaps, $α$ decay energies, rms radii, quadrupole deformations, potential energy curves, neutron density distributions, and neutron mean-field potentials are discussed.

nucl-th↗

arXiv2026

Hidden charm pentaquarks and the nature of $P_{c}$ states observed at LHCb

We carry out a unified study of the low-lying $1S$-wave compact states and hadronic molecules composed of hidden charm pentaquarks $qqqc\bar{c}$ ($q=u,d$) within a semirelativistic potential quark model. Apart from the linear confinement and one-gluon exchange potential between quarks and/or antiquarks, one-boson exchange potential is also included for baryon and meson clusters within the pentaquark system. We also evaluate the fall-apart decays by combining the obtained spectra within the quark exchange model. It is found that the $P_c (4312)^+$, $P_c (4440)^+$, and $P_c (4457)^+$ observed by the LHCb Collaboration in 2019 can be well explained by the hadronic molecules of $[Σ_c\bar{D}]_{1/2^-}^{1/2}(4318)$, $[Σ_c\bar{D}^*]_{1/2^-}^{1/2}(4437)$, and $[Σ_c\bar{D}^*]_{3/2^-}^{1/2}(4458)$, respectively. Meanwhile, $P_c(4380)^+$ reported by LHCb in 2015 may be assigned as the molecule $[Σ_c^*\bar{D}]_{3/2^-}^{1/2}(4382)$, except that it turns to be a narrow state other than a broad one shown by the experimental data. Our study shows that the $σ$- and $ρ$-meson exchanges are crucial for the formation of $Σ_c^{(*)}\bar{D}^{(*)}$ bound states with isospin $I=1/2$. Depending on the potential strength of the $σ$ exchange, there may exist very shallow bound states of $Λ_c\bar{D}^{(*)}$ with isospin $I=1/2$ and $Σ_c^{(*)}\bar{D}^{(*)}$ with isospin $I=3/2$. Our study may provide useful information for further exploring the hidden-charm pentaquarks in future experiments.

hep-ph↗

arXiv2026

Identification of $D_{s1}(2933)$ as the $2P_{1}$ state in the quark model

We investigate the internal structure of the newly observed charm-strange meson $D_{s1}(2933)^{+}$, which was reported by the LHCb Collaboration in $B^{0}\to D^{+}D^{-}K^{+}π^{-}$, in the quark model by treating it as the $2P_{1}$ state of the $c\bar{s}$ system. The coupled-channel corrections to the ${}^{1}P_1$--${}^{3}P_1$ mass matrix are evaluated through the two-point self-energy loops involving the $DK^{*}$, $D^{*}K$, $D^{*}K^{*}$, $D_{s}ϕ$, $D_{s}^{*}ϕ$ and $D_{s}^{*}η$ intermediate channels. Requiring the corrected eigenvalue to reproduce the measured mass yields a cutoff scale of about $0.82~\mathrm{GeV}$, a $2P_{1}^{\prime}$ partner state at $3012~\mathrm{MeV}$, and a mixing angle of $-12.9^{\circ}$ that deviates significantly from the heavy-quark ideal-mixing angle. Moreover, the predicted three-body branching ratio fraction $R_{\text{th}}=1.98$ for $D_{s1}(2933)\to D^{+}K^{+}π^{-}$ via the $DK^{*}$ and $D_{2}^{*}K$ intermediate states is consistent with the experimental value $R_{\text{exp}}=1.27^{+1.29}_{-0.95}$ within uncertainties. These results support the assignment of $D_{s1}(2933)$ as the $2P_{1}$ excited state of the $c\bar{s}$ system with final state interactions.

hep-ph↗

arXiv2026

A new type of skin thickness in high-spin isomers to constrain equation of state of spin-polarized nuclear matter

We explore experimental probes for constraining the equation of state (EOS) of spin-polarized nuclear matter, where spins of nucleons are aligned along a particular direction. For this purpose, we calculate the $12^+$ isomeric state of the \ce{^{52}Fe} nucleus with the relativistic point-coupling model. We argue that the spin skin thickness of this high-spin state, that is, the difference between the radius of the spin-up density and that of the spin-down density, strongly correlates with the spin slope parameter of the EOS. This is in analogy to the well known linear correlation between the slope parameter of the symmetry energy and the neutron skin thickness of finite nuclei. We show that this correlation is retained even when one considers the difference of the radii between the $12^+$ and the ground states, even though the correlation is much weaker than in the case of the difference between the spin-up and the spin-down radii. We also discuss the mean-square charge radii of the $12^+$ state. We find that by taking the square of the radii the dependence on the spin slope parameter becomes much stronger, and thus it can serve as a good probe of the spin slope parameter given a high resolution of laser-spectroscopy experiments.

nucl-th↗

arXiv2026

Probing Glueball content of X(2370) through heavy quarkonium radiative decays and electron-positron annihilation

In this paper, we first analyze the light-cone distribution amplitudes of the pseudoscalar Glueball and point out that the two-gluon and quark-antiquark pair contributions naturally mix at the quantum loop level. Based on the $η-η'-G-η_c$ tetra-mixing scheme and existing experimental results, we analyze the branching ratio of $J/ψ\to P+γ$ with pseudoscalar meson $P$ and extract the mixing parameters of the tetra-mixing scheme. We then successfully predict the branching ratio of $ψ(2S) \to P+γ$, which is found to be in good agreement with experimental results. We also find that the branching ratios of $J/ψ\to X(2370)+γ$ and $ψ(2S) \to X(2370)+γ$ are highly sensitive to the Glueball-charmonium mixing angle: the destructive mixing interference in the branching ratio of $J/ψ\to X(2370)+γ$ occurs at $ϕ_{gc}\approx0.01$, whereas that in $ψ(2S) \to X(2370)+γ$ occurs at $ϕ_{gc}\approx 0.11$. Moreover, the $J/ψ\to X(2370)+γ$ branching ratio exhibits constructive mixing interference when the mixing angle is larger than $ϕ_{gc}\approx 0.02$. Finally, we also study the electroproduction cross sections of pseudoscalar mesons. After excluding the resonance contributions, the theoretical calculations agree with the experimental measurements in order of magnitude, and we also present theoretical predictions for the electroproduction cross section of the $X(2370)$. These theoretical results can be readily tested by current BESIII and Belle-II experiments, and further experimental measurements will reveal the intrinsic nature of the $X(2370)$.

hep-ph↗

arXiv2026

Study of the $e^{+}e^{-}\to J/ψ\,π^{+}π^{-}$ lineshape near the $D^{*}\bar{D}+c.c.$ threshold and possible signals for exotic hidden charm states

We investigate the lineshape of the $e^{+}e^{-}\to J/ψ\,π^{+}π^{-}$ cross section in the vicinity of the $D^{*}\bar{D}+c.c.$ threshold, where the ``so-called'' $G(3900)$ is observed in the $e^+e^-\to D\bar{D}$ channel. To take into account the possible $D^{*}\bar{D}+c.c.$ open channel effects or possible contributions from $G(3900)$, we include the intermediate meson loop transitions in $e^{+}e^{-}\to J/ψ\,π^{+}π^{-}$. As a consequence, a triangle singularity (TS) is fulfilled which can produce nontrivial structures in the $J/ψπ$ invariant-mass spectrum. Moreover, the TS transition also allows access to exotic quantum number of $(I,J^{P(C)})=(1,1^{-(-)})$ in the $J/ψπ$ invariant-mass spectrum. We present predictions for the $J/ψ\,π$ invariant-mass spectrum and our results clarify the different manifestations of the kinematic effects and genuine resonances. In particular, we show that resonance structures arising from the $P$-wave $D\bar{D}$ scatterings or hidden charm tetraquark state with $(I,J^{P(C)})=(1,1^{-(-)})$ can be identified by the $J/ψπ$ invariant mass spectrum. It can provide a theoretical guidance for future experimental search for these exotic candidates.

hep-ph↗

arXiv2026

Singly heavy tetraquarks

In this work, we carry out a systematic study of the spectra of the $1S$-wave states for the whole singly-heavy tetraquark systems within a semi-relativistic hybrid quark potential model, in which both the one-gluon exchange (OGE) and one-boson exchange (OBE) interactions are included. Furthermore, the fall-apart decays are evaluated with the quark exchange model by combining the obtained spectra. It is found that besides the OGE potentials, the OBE potentials play crucial roles for describing the spectrum. All of our obtained states lie far above the lowest dissociation meson-meson threshold. They are compact states with relatively narrow fall-apart widths $\sim 1-120$~MeV. The $D_{s0}(2317)$, $D_{s1}(2460)$, $T_{b\bar{s}}(5568)$, and $T_{c\bar{s}}(2327)$ resonances reported from experiments cannot be explained as compact tetraquarks. While the $T_{\bar{c}\bar{s}0}(2870)$ and $T_{c\bar{s}0}(2900)$ favor the tetraquark states with $IJ^P=00^+$ and $10^+$, i.e. $T_{(\bar{c}\bar{s}[ud])0^+}^0(2919)$ and $T_{(cn\{\bar{s}\bar{n}\})0^+}^{1}(2922)$, respectively. More singly-heavy tetraquark states have good potentials to be observed in some of their dominant decay channels in experiments.

hep-ph↗

arXiv2026

Singly Cabibbo-suppressed hadronic weak decays of the $Ω^-$ hyperon

We study the two-body hadronic weak decays of the $Ω^-$ hyperon with strangeness $S=-3$, including three singly Cabibbo-suppressed decay modes: $Ξ^0 π^-$, $Ξ^-π^0$ and $ΛK^-$. The decay amplitudes at the quark level, arising from $s\to ud \bar{u}$ transitions (direct pion emission and color-suppressed processes) and $su\to ud$ transitions (pole terms), are calculated in the framework of the non-relativistic constituent quark model.The theoretical results show that the $Ξ^0 π^-$ channel is dominated by the color-allowed direct pion emission process, while the $ΛK^-$ channel is well described by one type of pole contribution mediated through intermediate $Ξ$ resonances ($1^2S_{1/2^+}$ and $1^2P_{1/2^-}$ states). However, the contribution from tree-level mechanisms alone to the branching ratio of $Ω^- \to Ξ^- π^0$ is small due to its color-suppressed nature. The discrepancy is resolved by including final state interactions through rescattering processes via intermediate states $Ξ^0π^-$ and $ΛK^-$. This work demonstrates that a unified description of $Ω^-$ hadronic weak decays necessitates the interplay of quark-level weak vertices, baryon pole structures, and long-distance final state rescattering dynamics. With these mechanisms, the obtained branching ratios are in agreement with the high-precision experimental data from the BESIII. Furthermore, these above decays are found to be dominated by the parity-conserving $P$-wave transitions, thus the asymmetry parameters are almost zero.

hep-ph↗

arXiv2026

Constraining the nuclear symmetry energy with electric dipole polarizability and neutron skin characteristics in \texorpdfstring{$^{208}\mathrm{Pb}$}{208Pb} within antisymmetrized molecular dynamics

The electric dipole polarizability $α_D$ and the neutron-skin thickness $ΔR_{np}$ of $^{208}\mathrm{Pb}$ are two powerful and clean probes for constraining the symmetry energy at subsaturation densities. Within the framework of the antisymmetrized molecular dynamics (AMD) model, the width of the strength function and its dynamical origins are understood, and the $α_D$ and $ΔR_{np}$ data favor effective interaction parameter sets with $S_0\approx32$-34 MeV and $L=64$-87 MeV. In addition, our calculations show that the sensitive densities of $α_D$ and $ΔR_{np}$ range from 0.2$ρ_0$ to 0.57$ρ_0$, and the corresponding values of the symmetry energy at the lower and upper ends of this sensitive density region are $S(0.2ρ_0)=10.18\pm 1.10$ MeV and $S(0.57ρ_0)=22.31\pm 1.32$ MeV.

nucl-th↗

arXiv2026

Superconducting dome and field-enhanced superconductivity of PLD synthesized Nd1-xEuxNiO2 thin films

We report on the synthesis of infinite-layer Nd1-xEuxNiO2 (0<x<0.7) thin films using pulsed laser deposition (PLD) followed by topotactic reduction with CaH2. Resistivity measurements on these films reveal a superconducting dome within the doping range 0.2<x<0.5, which is wider than that achieved by molecular beam epitaxy and comparable to that obtained by chemical synthesis. The x=0.3 PLD film exhibits the optimal superconducting transition temperature Tc~31 K, much higher than those grown by other vacuum epitaxial techniques. This result indicates that PLD is an ideal approach for fabricating high-quality, high-Tc Nd1-xEuxNiO2 superconducting films. Magneto-transport measurements reveal robust field-enhanced and re-entrant superconductivity in both underdoped and overdoped regimes. At low temperatures just above the onset Tc, the Hall resistance exhibits nonlinear behavior, which may originate from magnetic impurity scattering. These results highlight the crucial role of magnetic rare-earth Eu2+ ions in producing the exotic physical properties of the infinite-layer nickelates.

cond-mat.supr-con↗

arXiv2026

Near-threshold scattering of proton and Omega baryon and possible bound states

We study the near-threshold scattering and bound-state structure of the $NΩ$ system by solving the Lippmann-Schwinger (L-S) equation within the framework of the meson exchange model and the Pomeron exchange model. The numerical results indicate that after incorporating the Pomeron exchange mechanism, the observables of the ${^5}S{_2}$ channel, such as the binding energy, scattering length, and effective range, agree better with the experimental measurements. In addition, The Pomeron exchange can provide an extra attractive interaction to make the hadronic state more compact. We also predict the scattering behavior of the ${^3}S{_1}$ channel and confirm that a weak quasi-bound state exists in this channel. Future experimental measurements on the ${^3}S{_1}$ channel will provide an important criterion for verifying the dynamic role played by the Pomeron exchange mechanism within the $NΩ$ system.

hep-ph↗

arXiv2026

Revisiting neutron-skin thickness and dipole polarizability constraints on the symmetry energy in Antisymmetrized Molecular Dynamics

The neutron-skin thickness and electric dipole polarizability are among the most sensitive probes of the symmetry energy at subsaturation densities. Motivated by the tension raised by recent analyses of PREX-II and CREX data within density-functional-based approaches, we perform a unified study of static and dynamical isovector observables within the antisymmetrized molecular dynamics (AMD) framework. Using thirty interaction parameter sets that span different values of the symmetry-energy coefficient $S_0$, slope parameter $L$, and neutron-proton effective-mass splitting $Δm_{np}^*$, we systematically analyze the neutron-skin thicknesses of nuclei from $^{40}$Ca to $^{238}$U together with the electric dipole polarizability $α_D$ of $^{208}$Pb. A combined $χ^2$ analysis of neutron-skin thicknesses and the electric dipole polarizability yields preferred values of $L$ that increase with $S_0$, reflecting the joint constraint from the static and dynamical observables. Furthermore, we identify the density region mainly probed by these observables as 0.019 $\le ρ/ρ_0\le $0.60, where the relative narrowing strength function varies by less than 10% compared to its maximum narrowing strength. The maximum reduction of the uncertainty of $S(ρ)$ occurs at 0.28 $ρ_0$, where the symmetry energy within 1$σ_{post}$ uncertainty is constrained to be $S(0.28ρ_0) = 13.84\pm 1.31$ MeV. These results demonstrate that a unified AMD analysis of neutron-skin systematics and dipole polarizability provides a complementary constraint on the symmetry energy below saturation density.

nucl-th↗

arXiv2026

Fully-strange tetraquarks: fall-apart decays and experimental candidates

We presents a systematic analysis of the fall-apart decays for the $1S$, $1P$, and $2S$-wave fully-strange tetraquark states. It shows that most of the fully-strange tetraquark states have a relatively narrow fall-apart decay width of $\mathcal{O}(10)$ MeV. The newly observed axial-vector state $X(2300)$ at BESIII may favor the low-lying $1S$-wave $1^{+-}$ state $T_{(4s)1^{+-}}(2323)$, while the $X(2500)$ resonance observed in the earlier BESIII experiment may favor the low-lying $1P$-wave $0^{-+}$ state $T_{(4s)0^{-+}}(2481)$. Some fully-strange tetraquark states predicted in theory can be searched for in their dominant fall-apart decay channels in experiment, such as $ϕϕ$, $ϕϕ(1680)$, $η^{(\prime)}ϕ$, $η^{(\prime)}h_1(1415)$, and $ϕf_2^{\prime}(1525)$, to which they have relatively large couplings.

hep-ph↗

arXiv2026

The heavy flavor conserving hadronic weak decay of the ground-state bottom baryons

In this work the heavy flavor conserving (HFC) hadronic weak decays of bottom baryons are studied in the framework of the nonrelativistic constituent quark model (NRCQM). We show that the pole terms play an indispensable role in the description of the branching ratio of $Ξ_b^-\to Λ_b^0 π^-$. With the pole terms included we can make reliable predictions for $Ξ_b^0\to Λ_b^0 π^0$. A combined study of the HFC hadronic weak decays allows us to make a reasonable prediction for $Ω_b^-\toΞ_b^{-(0)}π^{0(-)}$, which can be searched for at LHCb and Belle-II experiments.

hep-ph↗

arXiv2026

Nature of $K^*(1680)$ and $q\bar{q}$-hybrid mixing as the SU(3) partner of $η_{1}(1855)$ in the strange sector

We presents an investigation of the $K^*(1680)$ state in its strong decays into two-body finial states within the flux-tube model and quark pair creation model. Since the charge conjugation parity is not conserved in the strange sector, the conventional $q\bar{q}$ states of $J^{P(C)}=1^{-(-)}$ can mix with the lowest hybrid states with $J^{P(C)}=1^{-(+)}$. Our analysis of the $K^*(1680)$ two-body strong decays indicates that the decay pattern of $K^*(1680)$ cannot be explained by the conventional $q\bar{q}$ scenario. Meanwhile, strong evidence shows the $q\bar{q}$-hybrid mixing mechanism in the strange sector. The phenomenological consequences of such a mixing are also discussed. Our study can provide a guidance for the future search for hybrid multiplets in experiment at BESIII, LHCb, and Belle-II.

hep-ph↗