arXiv subjects

Zhi-Gang Wang

Publications and source records attributed to Zhi-Gang Wang.

At least 145 records · Page 8Linked to original sources

arXiv2020

Analysis of the $Ω_b(6316)$, $Ω_b(6330)$, $Ω_b(6340)$ and $Ω_b(6350)$ with QCD sum rules

In this article, we introduce an explicit P-wave to construct three-quark currents to study the P-wave $Ω_b$ states with the full QCD sum rules. The predicted masses have a hierarchy if the same parameters are chosen and favor assigning the $Ω_b(6316)$, $Ω_b(6330)$, $Ω_b(6340)$ and $Ω_b(6350)$ to be the P-wave $Ω_b$ states with the $J^P={\frac{3}{2}}^-$, ${\frac{1}{2}}^-$, ${\frac{5}{2}}^-$ and ${\frac{3}{2}}^-$, respectively.

hep-ph↗

arXiv2020

Construction of univalent harmonic mappings convex in one direction

In the present paper, we derive several conditions of linear combinations and convolutions of harmonic mappings to be univalent and convex in one direction, one of them gives a partial answer to an open problem proposed by Dorff. The results presented here provide extensions and improvements of those given in some earlier works. Several examples of univalent harmonic mappings convex in one direction are also constructed to demonstrate the main results.

math.CV↗

arXiv2020

On quasiconformal close-to-convex harmonic mappings involving starlike functions

In the present paper, we discuss several basic properties of a class of quasiconformal close-to-convex harmonic mappings with starlike analytic part, such results as coefficient inequalities, an integral representation, a growth theorem, an area theorem, and radii of close-to-convexity of partial sums of the class, are derived.

math.CV↗

arXiv2020

Axialvector tetraquark candidates for the $Z_c(3900)$, $Z_c(4020)$, $Z_c(4430)$, $Z_c(4600)$

In this paper, we construct the axialvector and tensor current operators to investigate the ground state tetraquark states and the first radially excited tetraquark states with the quantum numbers $J^{PC}=1^{+-}$ via the QCD sum rules systematically, and observe that there are one axialvector tetraquark candidate for the $Z_c(3900)$ and $Z_c(4430)$, two axialvector tetraquark candidates for the $Z_c(4020)$, three axialvector tetraquark candidates for the $Z_c(4600)$.

hep-ph↗

arXiv2019

Analysis of the masses and decay constants of the heavy-light mesons with QCD sum rules

In this article, we calculate the contributions of the vacuum condensates up to dimension-6 including the $\mathcal{O}(α_s)$ corrections to the quark condensates in the operator product expansion, then study the masses and decay constants of the pseudoscalar, scalar, vector and axial-vector heavy-light mesons with the QCD sum rules in a systematic way. The masses of the observed mesons $(D,D^*)$, $(D_s,D_s^*)$, $(D_0^*(2400),D_1(2430))$, $(D_{s0}^*(2317),D_{s1}(2460))$, $(B,B^*)$, $(B_s,B_s^*)$ can be well reproduced, while the predictions for the masses of the $(B^*_{0}, B_{1})$ and $(B^*_{s0}, B_{s1})$ can be confronted with the experimental data in the future. We obtain the decay constants of the pseudoscalar, scalar, vector and axial-vector heavy-light mesons, which have many phenomenological applications in studying the semi-leptonic and leptonic decays of the heavy-light mesons.

hep-ph↗

arXiv2019

Analysis of the $P_c(4312)$, $P_c(4440)$, $P_c(4457)$ and related hidden-charm pentaquark states with QCD sum rules

In this article, we restudy the ground state mass spectrum of the diquark-diquark-antiquark type $uudc\bar{c}$ pentaquark states with the QCD sum rules by carrying out the operator product expansion up to the vacuum condensates of $13$ in a consistent way. The predicted masses support assigning the $P_c(4312)$ to be the hidden-charm pentaquark state with $J^{P}={\frac{1}{2}}^-$, assigning the $P_c(4440)$ to be the hidden-charm pentaquark state with $J^{P}={\frac{1}{2}}^-$, ${\frac{3}{2}}^-$ or ${\frac{5}{2}}^-$, assigning the $P_c(4457)$ to be the hidden-charm pentaquark state with $J^{P}={\frac{1}{2}}^-$ or ${\frac{3}{2}}^-$.

hep-ph↗

arXiv2019

Revisit the $X(4274)$ as the axialvector tetraquark state

In this article, we construct the $[sc]_A[\bar{s}\bar{c}]_V-[sc]_V[\bar{s}\bar{c}]_A$ type tensor current to study the mass and width of the $X(4274)$ with the QCD sum rules in details. The predicted mass $M_{X}=(4.27\pm0.09) \, \rm{GeV}$ for the $J^{PC}=1^{++}$ tetraquark state is in excellent agreement with the experimental data $4273.3 \pm 8.3 ^{+17.2}_{-3.6} \mbox MeV}$ from the LHCb collaboration. The central value of the width $Γ(X(4274)\to J/ψϕ)=47.9\,{\rm{MeV}}$ is in excellent agreement with the experimental data $56 \pm 11 ^{+8}_{-11} \mbox MeV}}$ from the LHCb collaboration. The present work supports assigning the $X(4274)$ to be the $J^{PC}=1^{++}$ $[sc]_A[\bar{s}\bar{c}]_V-[sc]_V[\bar{s}\bar{c}]_A$ tetraquark state with a relative P-wave between the diquark and antidiquark constituents. Furthermore, we obtain the mass of the $[sc]_A[\bar{s}\bar{c}]_V-[sc]_V[\bar{s}\bar{c}]_A$ type tetraquark state with $J^{PC}=1^{-+}$ as a byproduct.

hep-ph↗

arXiv2019

Vector hidden-bottom tetraquark candidate: $Y(10750)$

In this article, we take the scalar diquark and antidiquark operators as the basic constituents, construct the $Cγ_5\otimes\stackrel{\leftrightarrow}{\partial}_μ\otimes γ_5C$ type tetraquark current to study the $Y(10750)$ with the QCD sum rules. The predicted mass $M_{Y}=10.75\pm0.10\,\rm{GeV}$ and width $Γ_Y= 33.60^{+16.64}_{-9.45}\,{\rm{MeV}}$ support assigning the $Y(10750)$ to be the diquark-antidiquark type vector hidden-bottom tetraquark state, which has a relative P-wave between the diquark and antidiquark constituents.

hep-ph↗

arXiv2019

Analysis of the axialvector $B_c$-like tetraquark states with the QCD sum rules

In this article, we construct the diquark-antidiquark type current operators to study the axialvector $B_c$-like tetraquark states with the QCD sum rules. In calculations, we take the energy scale formula as a powerful constraint to choose the ideal energy scales of the QCD spectral densities and add detailed discussions to illustrate why we take the energy scale formula to improve the QCD sum rules for the doubly heavy tetraquark states. The predicted masses $M_{Z_{\bar{b}c}(1^{+-})}=7.30\pm0.08\,\rm{GeV}$ and $M_{Z_{\bar{b}c}(1^{++})}=7.31\pm0.08\,\rm{GeV}$ lie between the conventional $2\rm{P}$ and $3\rm{P}$ $B_c$ states with $J^P=1^+$ from the potential quark models, which is a typical feature of the diquark-antidiquark type $B_c$-like tetraquark states.

hep-ph↗

arXiv2019

Light tetraquark state candidates

In this article, we study the axialvector-diquark-axialvector-antidiquark type scalar, axialvector, tensor and vector $ss\bar{s}\bar{s}$ tetraquark states with the QCD sum rules. The predicted mass $m_{X}=2.08\pm0.12\,\rm{GeV}$ for the axialvector tetraquark state is in excellent agreement with the experimental value $(2062.8 \pm 13.1 \pm 4.2) \,\rm{MeV}$ from the BESIII collaboration and supports assigning the new $X$ state to be a $ss\bar{s}\bar{s}$ tetraquark state with $J^{PC}=1^{+-}$. The predicted mass $m_{X}=3.08\pm0.11\,\rm{GeV}$ disfavors assigning the $ϕ(2170)$ or $Y(2175)$ to be the vector partner of the new $X$ state. As a byproduct, we obtain the masses of the corresponding $qq\bar{q}\bar{q}$ tetraquark states. The light tetraquark states lie in the region about $2\,\rm{GeV}$ rather than $1\,\rm{GeV}$.

hep-ph↗

arXiv2019

Scalar or vector tetraquark state candidate: $Z_c(4100)$

In this article, we separate the vector and axialvector components of the tensor diquark operators explicitly, construct the axialvector-axialvector type and vector-vector type scalar tetraquark currents and scalar-tensor type tensor tetraquark current to study the scalar, vector and axialvector tetraquark states with the QCD sum rules in a consistent way. The present calculations do not favor assigning the $Z_c(4100)$ to be a scalar or vector tetraquark state. If the $Z_c(4100)$ is a scalar tetraquark state without mixing effects, it should have a mass about $3.9\,\rm{GeV}$ or $4.0\,\rm{GeV}$ rather than $4.1\,\rm{GeV}$; on the other hand, if the $Z_c(4100)$ is a vector tetraquark state, it should have a mass about $4.2\,\rm{GeV}$ rather than $4.1\,\rm{GeV}$. However, if we introduce mixing, a mixing scalar tetraquark state can have a mass about $4.1\,\rm{GeV}$. As a byproduct, we obtain an axialvector tetraquark candidate for the $Z_c(4020)$.

hep-ph↗

arXiv2019

The analysis of the excited bottom and bottom strange states $B_{1}(5721)$, $B_{2}^{}(5747)$, $B_{s1}(5830)$, $B_{s2}^{}(5840)$, $B_{J}(5840)$ and $B_{J}(5970)$ in B meson family

In order to make a further confirmation about the assignments of the excited bottom and bottom strange mesons $B_{1}(5721)$, $B_{2}^{*}(5747)$, $B_{s1}(5830)$, $B_{s2}^{*}(5840)$ and meanwhile identify the possible assignments of $B_{J}(5840)$, $B_{J}(5970)$, we study the strong decays of these states with the $^{3}P_{0}$ decay model. Our analysis support $B_{1}(5721)$ and $B_{2}^{*}(5747)$ to be the $1P_{1}'$ and $1^{3}P_{2}$ assignments and the $B_{s1}(5830)$, $B_{s2}^{*}(5840)$ to be the strange partner of $B_{1}(5721)$ and $B_{2}^{*}(5747)$. Besides, we tentatively identify the recently observed $B_{J}(5840)$, $B_{J}(5970)$ as the $2^{3}S_{1}$ and $1^{3}D_{3}$ states, respectively. It is noticed that this conclusion needs further confirmation by measuring the decay channel to $Bπ$ of $B_{J}(5840)$ and $B_{J}(5970)$ in experiments.

hep-ph↗

arXiv2019

Analysis of the $\bar{D}Σ_c$, $\bar{D}Σ_c^$, $\bar{D}^{}Σ_c$ and $\bar{D}^{}Σ_c^$ pentaquark molecular states with QCD sum rules

In this article, we study the $\bar{D}Σ_c$, $\bar{D}Σ_c^*$, $\bar{D}^{*}Σ_c$ and $\bar{D}^{*}Σ_c^*$ pentaquark molecular states with the QCD sum rules by carrying out the operator product expansion up to the vacuum condensates of dimension $13$ in a consistent way. The present calculations support assigning the $P_c(4312)$ to be the $\bar{D}Σ_c$ pentaquark molecular state with $J^P={\frac{1}{2}}^-$, assigning the $P_c(4380)$ to be the $\bar{D}Σ_c^*$ pentaquark molecular state with $J^P={\frac{3}{2}}^-$, assigning the $P_c(4440/4457)$ to be the $\bar{D}^{*}Σ_c$ pentaquark molecular state with $J^P={\frac{3}{2}}^-$ or the $\bar{D}^{*}Σ_c^*$ pentaquark molecular state with $J^P={\frac{5}{2}}^-$. Special attentions are payed to the operator product expansion.

hep-ph↗

arXiv2019

Analysis of the hidden-bottom tetraquark mass spectrum with the QCD sum rules

In this article, we extend our previous work to study the mass spectrum of the ground state hidden-bottom tetraquark states with the QCD sum rules in a systematic way. The predicted hidden-bottom tetraquark masses can be confronted to the experimental data in the future to diagnose the nature of the $Z_b$ states. In calculations, we observe that the scalar diquark states, the axialvector diquark states and the axialvector components of the tensor diquark state are all good diquarks in building the lowest tetraquark states.

hep-ph↗

arXiv2019

Analysis of the vector and axialvector $QQ\bar{Q}\bar{Q}$ tetraquark states with QCD sum rules

In this article, we construct the axialvector-diquark-axialvector-antidiquark type currents to study both the vector and axialvector $QQ\bar{Q}\bar{Q}$ tetraquark states with the QCD sum rules, and obtain the masses $M_{Y(cc\bar{c}\bar{c},1^{+-})} =6.05\pm0.08\,\rm{GeV}$, $M_{Y(cc\bar{c}\bar{c},1^{--})} =6.11\pm0.08\,\rm{GeV}$, $M_{Y(bb\bar{b}\bar{b},1^{+-})} =18.84\pm0.09\,\rm{GeV}$, $M_{Y(bb\bar{b}\bar{b},1^{--})} =18.89\pm0.09\,\rm{GeV}$. The vector tetraquark states lie $40\,\rm{MeV}$ above the corresponding centroids of the $0^{++}$, $1^{+-}$ and $2^{++}$ tetraquark states, which is a typical feature of the vector tetraquark states consist of four heavy quarks.

hep-ph↗

arXiv2019

Analysis of strong decays of the $Z_c(4600)$ with the QCD sum rules

In this article, we tentatively assign the $Z_c(4600)$ to be the $[dc]_P[\bar{u}\bar{c}]_A-[dc]_A[\bar{u}\bar{c}]_P$ type vector tetraquark state and study its two-body strong decays with the QCD sum rules based on solid quark-hadron duality, the predictions for the partial decay widths $Γ(Z_c^-\to J/ψπ^-)=41.4^{+20.5}_{-14.9}\,\rm{MeV}$, $Γ(Z_c^-\to η_cρ^-)=41.6^{+32.7}_{-22.2}\,\rm{MeV}$, $Γ(Z_c^-\to J/ψa_0^-(980))=10.2^{+11.3}_{-6.7}\,\rm{MeV}$, $Γ(Z_c^-\to χ_{c0}ρ^-)=3.5^{+6.7}_{-3.0}\,\rm{MeV}$, $Γ(Z_c^-\to D^{*0} D^{*-})=39.5^{+29.6}_{-19.3}\,\rm{MeV}$, $Γ(Z_c^-\to D^{0} D^{-})=6.6^{+4.6}_{-3.0}\,\rm{MeV}$ and $Γ(Z_c^-\to D^{*0} D^{-})=1.0^{+1.0}_{-0.6}\,\rm{MeV}$ can be confronted to the experimental data in the future to diagnose the nature of the $Z_c(4600)$.

hep-ph↗

arXiv2019

Analysis of the $D\bar{D}^*K$ system with QCD sum rules

In this article, we construct the color singlet-singlet-singlet interpolating current with $I\left(J^P\right)=\frac{3}{2}\left(1^-\right)$ to study the $D\bar{D}^*K$ system through QCD sum rules approach. In calculations, we consider the contributions of the vacuum condensates up to dimension-16 and employ the formula $μ=\sqrt{M_{X/Y/Z}^{2}-\left(2{\mathbb{M}}_{c}\right)^{2}}$ to choose the optimal energy scale of the QCD spectral density. The numerical result $M_Z=4.71_{-0.11}^{+0.19}\,\rm{GeV}$ indicates that there exists a resonance state $Z$ lying above the $D\bar{D}^*K$ threshold to saturate the QCD sum rules. This resonance state $Z$ may be found by focusing on the channel $J/ψπK$ of the decay $B\longrightarrow J/ψππK$ in the future.

hep-ph↗

arXiv2019

Strong decays of the $Y(4660)$ as a vector tetraquark state in solid quark-hadron duality

In this article, we choose the $[sc]_P[\bar{s}\bar{c}]_A-[sc]_A[\bar{s}\bar{c}]_P$ type tetraquark current to study the hadronic coupling constants in the strong decays $Y(4660)\to J/ψf_0(980)$, $η_c ϕ(1020)$, $χ_{c0}ϕ(1020)$, $D_s\bar{D}_s$, $ D_s^* \bar{D}^*_s$, $ D_s \bar{D}^*_s$, $D_s^* \bar{D}_s$, $ψ^\prime π^+π^-$, $J/ψϕ(1020)$ with the QCD sum rules based on solid quark-hadron quality. The predicted width $Γ(Y(4660) )= 74.2^{+29.2}_{-19.2}\,{\rm{MeV}}$ is in excellent agreement with the experimental data $68\pm 11\pm 1 {\mbox{ MeV}}$ from the Belle collaboration, which supports assigning the $Y(4660)$ to be the $[sc]_P[\bar{s}\bar{c}]_A-[sc]_A[\bar{s}\bar{c}]_P$ type tetraquark state with $J^{PC}=1^{--}$. In calculations, we observe that the hadronic coupling constants $ |G_{Yψ^\prime f_0}|\gg |G_{Y J/ψf_0}|$, which is consistent with the observation of the $Y(4660)$ in the $ψ^\primeπ^+π^-$ mass spectrum, and favors the $ψ^{\prime}f_0(980)$ molecule assignment. It is important to search for the process $Y(4660)\to J/ψϕ(1020)$ to diagnose the nature of the $Y(4660)$, as the decay is greatly suppressed.

hep-ph↗