arXiv subjects

Wen-Shuai Zhang

Publications and source records attributed to Wen-Shuai Zhang.

7 recordsLinked to original sources

arXiv2026

QCD Sum Rule Analysis of Triply Heavy $(Q\bar{Q})(Q\bar{q})$ Tetraquark States with $J^P=0^{\pm}$

Within the framework of QCD sum rules, we systematically investigate the mass spectra and possible decay patterns of the $(c\bar{c})(c\bar{q})$ and $(b\bar{b})(b\bar{q})$ tetraquark states with quantum numbers $J^{P}=0^{\pm}$. Based on two distinct color configurations, $[8_c]_{Q\bar{Q}} \otimes [8_c]_{Q\bar{q}}$ and $[1_c]_{Q\bar{Q}} \otimes [1_c]_{Q\bar{q}}$, we construct 18 interpolating currents for these states, and obtain stable sum rules for a subset of them. By calculating the corresponding two-point correlation functions, we extract their mass spectra. For the $(c\bar{c})(c\bar{q})$ system, we identify four possible tetraquark states: two with $J^{P}=0^+$, namely $T_{3c,0}(4760)$ and $T_{3c,0}(5000)$, and two with $J^{P}=0^-$, denoted as $T_{3c,0}(5040)$ and $T_{3c,0}(5370)$. For the $(b\bar{b})(b\bar{q})$ system, the extracted masses are found to lie in the ranges $13.72$--$14.02$ GeV for the $J^{P}=0^+$ states and $13.90$--$14.22$ GeV for the $J^{P}=0^-$ states. We further analyze their possible decay modes. Our results indicate that $T_{3c,0}(5000)$, $T_{3c,0}(5040)$, and $T_{3c,0}(5370)$ can decay into a charmonium state and a charmed meson, and are therefore expected to have appreciable decay widths. By contrast, $T_{3c,0}(4760)$ and all predicted $(b\bar{b})(b\bar{q})$ tetraquark states are expected to be relatively narrow, since the corresponding two-body strong decays via the fall-apart mechanism are kinematically forbidden. Therefore, $T_{3c,0}(4760)$ and all predicted $(b\bar{b})(b\bar{q})$ tetraquark states are promising candidates for experimental searches in final states containing a $D$ or a $\bar{B}$ meson, accompanied by light hadrons or a photon.

hep-ph↗

arXiv2026

QCD Sum Rule Analysis of a Compact $D^{+}D^{-}K^{+}$-Like Hidden-Charm Hexaquark with $J^{P}=0^{-}$

In this work, we study a compact hexaquark configuration motivated by the same quark content as $D^{+} D^{-} K^+$ using QCD sum rules, where the $D D K$ system has been extensively studied within theoretical frameworks of few-body hadronic dynamics and coupled-channel interactions. The state is constructed from three color-octet quark--antiquark clusters coupled to an overall color singlet. We construct six independent local interpolating currents with the quantum numbers $J^{P}=0^{-}$ and analyze the corresponding two-point correlation functions. Both perturbative contributions and nonperturbative condensates up to dimension ten are included in the operator product expansion. Our analysis indicates that, within Borel windows satisfying standard sum rule criteria and with a reasonable choice of continuum threshold, the mass of the $J^{P}=0^{-}$ hidden-charm hexaquark state is estimated to be in the range $3.94$--$4.41~\mathrm{GeV}$. This prediction can provide a valuable theoretical reference for identifying such exotic hidden-charm hexaquark state in future experiments.

hep-ph↗

arXiv2024

Investigating triply heavy tetraquark states through QCD sum rules

We apply the method of QCD sum rules to study the $QQ\bar{Q}\bar{q}$ and $QQ\bar{Q}\bar{s}$ tetraquark states, where $Q=c,b$ and $q=u,d$, with the quantum number $J^P = 0^{+}$. We consider the contributions of vacuum condensates up to dimension-9 in the operator product expansion, and use the energy scale formula $μ= \sqrt{M_{X}^2 - (i\mathbb{M}_c + j\mathbb{M}_b)^2} - k\mathbb{M}_s$ to determine the optimal energy scales for the QCD spectral densities. Our results indicate that triply charm tetraquark states $cc\bar{c}\bar{q}$ and $cc\bar{c}\bar{s}$ have masses in the ranges of $5.38-5.84\,\text{GeV}$ and $5.66-6.16\,\text{GeV}$, respectively. In the bottom sector, triply bottom tetraquark states $bb\bar{b}\bar{q}$ and $bb\bar{b}\bar{s}$ have masses in the ranges of $14.89-15.55\,\text{GeV}$ and $14.95-15.66\,\text{GeV}$, respectively. This study could help distinguish these states in upcoming high-energy nuclear and particle experiments.

hep-ph↗

arXiv2015

Exploring positron characteristics utilizing two new positron-electron correlation schemes based on three electronic-structure calculation methods

We make a gradient correction to a new local density approximation form of positron-electron correlation. Then the positron lifetimes and affinities are probed by using these two approximation forms based on three electronic-structure calculation methods including the full-potential linearized augmented plane wave (FLAPW) plus local orbitals approach, the atomic superposition (ATSUP) approach and the projector augmented wave (PAW) approach. The differences between calculated lifetimes using the FLAPW and ATSUP methods are clearly interpreted in the view of positron and electron transfers. We further find that a well implemented PAW method can give near-perfect agreement on both the positron lifetimes and affinities with the FLAPW method, and the competitiveness of the ATSUP method against the FLAPW/PAW method is reduced within the best calculations. By comparing with experimental data, the new introduced gradient corrected correlation form is proved competitive for positron lifetime and affinity calculations.

cond-mat.mtrl-sci↗

arXiv2012

Generalized Holographic Dark Energy and its Observational Constraints

In the original holographic dark energy (HDE) model, the dark energy density is proposed to be $ρ_{de} = 3c^2M^2_{pl}L^{-2}$, with $c$ is a dimensionless constant characterizing the properties of the HDE. In this work, we propose the generalized holographic dark energy (GHDE) model by considering the parameter $c$ as a redshift-dependent function $c(z)$. We derive all the physical quantities of the GHDE model analytically, and fit the $c(z)$ by trying four kinds of parametrizations. The cosmological constraints of the $c(z)$ are obtained from the joint analysis of the present SNLS3+BAO+CMB+$H_0$ data. We find that, compared with the original HDE model, the GHDE models can provide a better fit to the data. For example, the GHDE model with JBP-type $c(z)$ can reduce the $χ^2_{min}$ of the HDE model by 2.16. We also find that, unlike the original HDE model with a phantom-like behavior in the future, the GHDE models can present many more different possibilities, i.e., it allows the GHDE in the future to be either quintessence like, cosmological constant like, or phantom like, depending on the forms of $c(z)$.

astro-ph.CO↗

arXiv2012

Testing modified gravity models with recent cosmological observations

We explore the cosmological implications of five modified gravity (MG) models by using the recent cosmological observational data, including the recently released SNLS3 type Ia supernovae sample, the cosmic microwave background anisotropy data from the Wilkinson Microwave Anisotropy Probe 7-yr observations, the baryon acoustic oscillation results from the Sloan Digital Sky Survey data release 7, and the latest Hubble constant measurement utilizing the Wide Field Camera 3 on the Hubble Space Telescope. The MG models considered include the Dvali-Gabadadze-Porrati(DGP) model, two $f(R)$ models, and two $f(T)$ models. We find that compared with the $Λ$CDM model, MG models can not lead to a appreciable reduction of the $χ^2_{min}$. The analysis of AIC and BIC shows that the simplest cosmological constant model($Λ$CDM) is still most preferred by the current data, and the DGP model is strongly disfavored. In addition, from the observational constraints, we also reconstruct the evolutions of the growth factor in these models. We find that the current available growth factor data are not enough to distinguish these MG models from the $Λ$CDM model.

astro-ph.CO↗

arXiv2011

Probing Cosmic Acceleration by Using the SNLS3 SNIa Dataset

We probe the cosmic acceleration by using the recently released SNLS3 sample of 472 type Ia supernovae. Combining this type Ia supernovae dataset with the cosmic microwave background anisotropy data from the Wilkinson Microwave Anisotropy Probe 7-yr observations, the baryon acoustic oscillation results from the Sloan Digital Sky Survey data release 7, and the Hubble constant measurement from the Wide Field Camera 3 on the Hubble Space Telescope, we measure the dark energy equation of state $w$ and the deceleration parameter $q$ as functions of redshift by using the Chevallier-Polarski-Linder parametrization. Our result is consistent with a cosmological constant at 1$σ$ confidence level, without evidence for the recent slowing down of the cosmic acceleration. Furthermore, we consider three binned parametrizations ($w$ is piecewise constant in redshift $z$) based on different binning methods. The similar results are obtained, i.e., the $Λ$CDM model is still nicely compatible with current observations.

astro-ph.CO↗