arXiv subjects

Qiang Zhao

Publications and source records attributed to Qiang Zhao.

At least 19 recordsLinked to original sources

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 $\eta-\eta'-G-\eta_c$ tetra-mixing scheme and existing experimental results, we analyze the branching ratio of $J/\psi \to P+\gamma$ with pseudoscalar meson $P$ and extract the mixing parameters of the tetra-mixing scheme. We then successfully predict the branching ratio of $\psi(2S) \to P+\gamma$, which is found to be in good agreement with experimental results. We also find that the branching ratios of $J/\psi \to X(2370)+\gamma$ and $\psi(2S) \to X(2370)+\gamma$ are highly sensitive to the Glueball-charmonium mixing angle: the destructive mixing interference in the branching ratio of $J/\psi \to X(2370)+\gamma$ occurs at $\phi_{gc}\approx0.01$, whereas that in $\psi(2S) \to X(2370)+\gamma$ occurs at $\phi_{gc}\approx 0.11$. Moreover, the $J/\psi \to X(2370)+\gamma$ branching ratio exhibits constructive mixing interference when the mixing angle is larger than $\phi_{gc}\approx 0.02$. 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

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

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 $N\Omega$ 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 $N\Omega$ 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 $\Delta m_{np}^*$, we systematically analyze the neutron-skin thicknesses of nuclei from $^{40}$Ca to $^{238}$U together with the electric dipole polarizability $\alpha_D$ of $^{208}$Pb. A combined $\chi^2$ 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 \rho/\rho_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 $S(\rho)$ occurs at 0.28 $\rho_0$, where the symmetry energy within 1$\sigma_{post}$ uncertainty is constrained to be $S(0.28\rho_0) = 13.84\pm 1.31$ 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

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 $\Xi_b^-\to \Lambda_b^0 \pi^-$. With the pole terms included we can make reliable predictions for $\Xi_b^0\to \Lambda_b^0 \pi^0$. A combined study of the HFC hadronic weak decays allows us to make a reasonable prediction for $\Omega_b^-\to\Xi_b^{-(0)}\pi^{0(-)}$, which can be searched for at LHCb and Belle-II experiments.

hep-ph↗

arXiv2026

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

We investigate the lineshape of the $e^{+}e^{-}\to J/\psi\,\pi^{+}\pi^{-}$ 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 $e^{+}e^{-}\to J/\psi\,\pi^{+}\pi^{-}$. As a consequence, a triangle singularity (TS) is fulfilled which can produce nontrivial structures in the $J/\psi\pi$ invariant-mass spectrum. Moreover, the TS transition also allows access to exotic quantum number of $(I,J^{P(C)})=(1,1^{-(-)})$ in the $J/\psi\pi$ invariant-mass spectrum. We present predictions for the $J/\psi\,\pi$ 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 $J/\psi\pi$ invariant mass spectrum. It can provide a theoretical guidance for future experimental search for these exotic candidates.

hep-ph↗

arXiv2026

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

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 $\alpha_D$ and the neutron-skin thickness $\Delta R_{np}$ 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 $\alpha_D$ and $\Delta R_{np}$ 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 $\alpha_D$ and $\Delta R_{np}$ range from 0.2$\rho_0$ to 0.57$\rho_0$, and the corresponding values of the symmetry energy at the lower and upper ends of this sensitive density region are $S(0.2\rho_0)=10.18\pm 1.10$ MeV and $S(0.57\rho_0)=22.31\pm 1.32$ MeV.

nucl-th↗

arXiv2026

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

We study the two-body hadronic weak decays of the $\Omega^-$ hyperon with strangeness $S=-3$, including three singly Cabibbo-suppressed decay modes: $\Xi^0 \pi^-$, $\Xi^-\pi^0$ and $\Lambda K^-$. 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 $\Xi^0 \pi^-$ channel is dominated by the color-allowed direct pion emission process, while the $\Lambda K^-$ channel is well described by one type of pole contribution mediated through intermediate $\Xi$ resonances ($1^2S_{1/2^+}$ and $1^2P_{1/2^-}$ states). However, the contribution from tree-level mechanisms alone to the branching ratio of $\Omega^- \to \Xi^- \pi^0$ is small due to its color-suppressed nature. The discrepancy is resolved by including final state interactions through rescattering processes via intermediate states $\Xi^0\pi^-$ and $\Lambda K^-$. This work demonstrates that a unified description of $\Omega^-$ 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

Combined analysis of the singly-Cabbibo-suppressed decays of $D^{0} \to VP$

We investigate six singly Cabibbo-suppressed decay channels in $D^0\to VP$ ( $V$ and $P$ stand for the ground state vector and pseudoscalar mesons, respectively), i.e. $D^{0}\to \rho^{+}\pi^{-}$, $\rho^{-}\pi^{+}$, $K^{*+}K^{-}$, $K^{*-}K^{+}$, $K^{*0}\bar{K}^{0}$, and $\bar{K}^{*0}K^{0}$. These decay channels share the similar transition mechanisms involving only the direct emission (DE) and internal conversion (IC) processes. We show that a combined analysis of these channels can explicitly highlight the role played by the IC processes which contribute to the amplitudes at the same order of magnitude as the DE processes.

hep-ph↗

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 $\phi\phi$, $\phi\phi(1680)$, $\eta^{(\prime)}\phi$, $\eta^{(\prime)}h_1(1415)$, and $\phi f_2^{\prime}(1525)$, to which they have relatively large couplings.

hep-ph↗

arXiv2026

Automated decision-making by chemical echolocation in active droplets

Motile microorganisms, like bacteria and algae, unify abilities like self-propulsion, autonomous navigation, and decision-making on the micron scale. While recent breakthroughs have led to the creation of synthetic microswimmers and nanoagents that can also self-propel, they still lack the functionality and sophistication of their biological counterparts. This study pioneers a mechanism enabling synthetic agents to autonomously navigate and make decisions, allowing them to solve mazes and transport cargo through complex environments without requiring external cues or guidance. The mechanism exploits chemo-hydrodynamic signals, produced by agents like active droplets or colloids, to remotely sense and respond to their environment - similar to echolocation. Our research paves the way for endowing autonomous, motile synthetic agents with functionalities that have been so far exclusive to biological organisms.

cond-mat.soft↗

arXiv2025

A unified approach for the hadronic weak decays of $\Lambda$ and $\Sigma^{\pm}\to N\pi$

We provide a unified approach for the two-body hadronic weak decays of hyperons with $S=-1$, i.e. $\Lambda$ and $\Sigma^\pm$, in the framework of the non-relativistic constitute quark model (NRCQM). A combined analysis shows that the branching ratios and asymmetry parameters of the decay channels $\Lambda\to p\pi^-$ and $\Sigma^\pm\to N\pi$ can be well described in the same framework with the direct pion emission, color suppressed internal $W$ emission, and pole terms included. However, the channel $\Lambda\to n\pi^0$ indicates significant deviations from the experimental data based on these mentioned transition mechanism. We demonstrate that the final state interactions (FSIs) via the coupled-channel rescatterings play a crucial role in $\Lambda\to n\pi^0$. Namely, the dominant decay channel of $\Lambda\to p\pi^-$ can contribute to $\Lambda\to n\pi^0$ via the $p\pi^-\to n\pi^0$ rescatterings. This is a leading correction effect for $\Lambda\to n\pi^0$ at the one-loop level. We find that such FSIs only become the leading effects in $\Lambda\to n\pi^0$, but contribute as subleading contributions in other channels. We also demonstrate that the pole terms are indispensable in these hyperon decays. In particular, for $\Sigma^-\to n\pi^-$ and $\Sigma^+\to n\pi^+$, it shows that $\Lambda(1405)$ as the intermediate state in the pole term amplitude is necessary for reproducing the experimental data. We also find that a dynamic selection rule forbids the radial excitation state $N(1710)$ of the quark model multiplet $|70, ^28,2,0^+,1/2^+\rangle$ from contribution. To some extent, the hyperon hadronic weak decays serve as a special probe for the underlying transition mechanisms and can provide some constraints on the intermediate $J^P=1/2^\pm$ baryon resonances.

hep-ph↗

arXiv2025

Huizhou Hadron Spectrometer -- a Proposed High-rate Experimental Setup at the High Intensity Heavy-ion Accelerator Facility

The High-Intensity Heavy-Ion Accelerator Facility (HIAF), currently under construction in Huizhou, Guangdong Province, China, is projected to be completed by 2025. This facility will be capable of producing proton and heavy-ion beams with energies reaching several GeV, thereby offering a versatile platform for advanced fundamental physics research. Key scientific objectives include exploring physics beyond the Standard Model through the search for novel particles and interactions, testing fundamental symmetries, investigating exotic hadronic states such as di-baryons, pentaquark states and multi-strange hypernuclei, conducting precise measurements of hadron and hypernucleus properties, and probing the phase boundary and critical point of nuclear matter. To facilitate these investigations, we propose the development of a dedicated experimental apparatus at HIAF - the Huizhou Hadron Spectrometer (HHaS). This paper presents the conceptual design of HHaS, comprising a solenoid magnet, a five-dimensional silicon pixel tracker, a Low-Gain Avalanche Detector (LGAD) for time-of-flight measurements, and a Cherenkov-scintillation dual-readout electromagnetic calorimeter. The design anticipates an unprecedented event rate of 1-100 MHz, extensive particle acceptance, a track momentum resolution at 1% level, an electromagnetic energy resolution of ~3% @ 1 GeV and multi-particle identification capabilities. Such capabilities position HHaS as a powerful instrument for advancing experimental studies in particle and nuclear physics. The successful realization of HHaS is expected to significantly bolster the development of medium- and high-energy physics research within China.

hep-ex↗

arXiv2025

Threshold effects as the origin of $Y(4500)$ observed in $e^+e^-\to J/ψK^+K^-$

The BESIII collaboration has recently observed a resonant structure $Y(4500)$ in $e^{+}e^{-}\to J/ψK^{+}K^{-}$, whose origin remains unresolved. In this study, we analyze the cross section line shape of $e^{+}e^{-}\to J/ψK^{+}K^{-}$ by taking into account the $ψ(4415)$ state and intermediate charmed meson loops. By treating $ψ(4415)$ as both a pure $S$-wave state and $S$-$D$ mixed states, and introducing the $Z_{cs}^{(\prime)}$ resonance, we find that the $Y(4500)$ peak at $\sqrt{s}=4.5~\text{GeV}$ arises from the triangle singularity mechanism in the $Z_{cs}^{(\prime)}$-mediated rescattering processes, supporting its interpretation as a threshold effect rather than a conventional resonance.

hep-ph↗

arXiv2025

A short review of the vector charmonium-like state $ψ(4230)$

We present a concise review of the vector charmonium state $ψ(4230)$, which was originally labelled as $Y(4260)$ in the literature. As one of the earliest candidates for a QCD exotic states, its interpretation has initiated various ideas about possible manifestations of non-perturbative mechanisms in the charmonium mass regime. In this short article we briefly review the experimental status of $ψ(4230)$ and discuss possible theoretical interpretations. We will focus on four broadly investigated scenarios, i.e. tetraquark, hybrid, hadro-quarkonium, and hadronic molecule, and highlight the key issues based on these approaches. Crucial experimental observables, e.g. mass position, lineshapes, di-lepton decay width $Γ_{ee}$, production rates in $B$ meson decays, dominant hadronic decay patterns, and the potential $1^{-+}$ and $0^{--}$ exotic partners, are assessed, which can provide crucial structure information for understanding this mysterious state.

hep-ph↗

arXiv2025

Predictions for the isospin-violating decays of $B_{c}(1P)^{+}\to B_{c}^{(*)+}π^{0}$

In this work we study the isospin-violating decays of $B_{c}(1P)^{+}\to B_{c}^{(*)+}π^{0}$, which may provide additional information for the determination of the properties of the first orbital excitation states of $B_{c}(1P)^{+}$. By assuming a dual relation between the U(1) anomaly soft-gluon coupling for $B_{c}(1P)^{+}\to B_{c}^{(*)+}π^{0}$ and the intermediate meson loop transitions, we can quantify the isospin-violating decay effects for these four $P$-wave states. We find that the partial decay width of $B_{c0}^{*+}\to B_{c}^{+}π^{0}$ is about three orders of magnitude larger than that for $B_{c2}^{*+}\to B_{c}^{+}π^{0}$. It implies that $B_{c0}^{*+}$ can be established in the $B_{c}^{+}π^{0}$ decay channel as a single state. Meanwhile, the two axial-vector states $B_{c1}^{+}/B_{c1}'^{+}$ can be possibly identified in $B_{c1}^{+}/B_{c1}'^{+}\to B_{c}^{*+}π^{0}$ with comparable strengths. Although these isospin-violating decays turn out to be small, the theoretical predictions should be useful for guiding future experimental efforts.

hep-ph↗