arXiv subjects

Bing-Dong Wan

Publications and source records attributed to Bing-Dong Wan.

28 records · Page 2Linked to original sources

arXiv2022

Gluonic nature of the newly observed state $X(2600)$

Motivated by the newly observed resonance $X(2600)$ by BESIII Collaboration, we examine the trigluon glueball interpretation for it in the framework of QCD sum rules. We evaluate the mass spectra of the trigluon glueballs with quantum numbers $0^{-+}$ and $2^{-+}$ up to dimension 8 condensate in the operator product expansion. Our numerical results indicate that the mass of the $2^{-+}$ trigluon glueball is about $2.66\pm 0.06$ GeV, which is consistent with the mass of the X(2600) within the uncertainties, while $0^{-+}$ has a mass of $2.01\pm0.14$ GeV. The possible decay channels of the $2^{-+}$ state are analyzed, which are crucial in decoding $X(2600)$'s internal structure and are hopefully measurable in BESIII, BEllEII, PANDA, and LHCb experiments.

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arXiv2022

Possible structure of the newly found exotic state $η_1(1855)$

Recently, a hadronic state named $η_1(1855)$, about 1.86 GeV, was observed in the BESIII experiment. This finding has a peculiar interest due to its exotic quantum number $J^{PC}=1^{-+}$. In this paper, we examine the tetraquark interpretation for the structure of $η_1(1855)$ in the configurations of $[1_c]_{\bar{s}s}\otimes[1_c]_{\bar{q}q}$ and $[1_c]_{\bar{s}q}\otimes[1_c]_{\bar{s}q}$, and perform a mass spectrum calculation in the framework of QCD sum rules. The results show that the observed $η_1(1855)$ could be embedded into the $[1_c]_{\bar{s}s}\otimes[1_c]_{\bar{q}q}$ configuration. The possible tetraquark and hybrid decay modes are analyzed, which are critical in decoding its inner structure. In the same way, we evaluate as well the $\bar{s}s\bar{s}s$ molecular state with $1^{-+}$ quantum number and find that there might exist two such ground states.

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arXiv2022

The tetra-heavy baryonium spectra

In this work, we investigate the spectra of the prospective tetracharm and tetrabottom baryonium, viz. the baryon-antibaryon states, in the framework of QCD sum rules. The non-perturbative contributions up to dimension 10 are taken into account. Numerical results indicate that there might exist 4 possible tetracharm baryonium states with masses $(7.33\pm0.12)$, $(7.42\pm0.13)$, $(7.68\pm0.17)$, and $(7.76\pm0.12)$ GeV for the quantum numbers of $0^{-+}$, $1^{--}$, $0^{++}$, and $1^{++}$, respectively. The corresponding tetrabottom partners are found lying respectively at $(19.41\pm 0.15)$, $(19.48\pm 0.15)$, $(19.77\pm 0.19)$ and $(19.84\pm 0.19)$ GeV. Additionally, we also analyze the spectra of the $\barΞ_{bc}Ξ_{bc}$ and $\barΞ_{cc}Ξ_{bb}$ baryonium states, which lie in the range of $13.77-14.40$ GeV and $13.39-14.14$ GeV, respectively. The possible baryonium decay modes are analyzed, which are hopefully measurable in LHC experiments.

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arXiv2022

Searching $B_c^\ast$ via conservation laws

To distinguish $B_c^{\ast +}(1^3S_1)$ and $B_c^+(1^1S_0)$ in the experiments, we propose two methods based on the conservation laws. I. From the angular momentum conservation, a nonzero helicity of $J/ψ$ of $B_c^{(\ast)+ } \to J/ψπ^+$ would be an evidence of $B_c^{\ast +}$. II. Since $B_c^+ \to B^+ ϕ$ is kinematically forbidden, $ B_c^{\ast +} \to B^+ ϕ$ provides a clean channel to probe $B_c^{\ast +}$\,. Particularly, our results show that $B_c^{\ast +}$ is promising to be observed at LHC via $B_c^{(\ast)+} \to J/ψπ^+$. On the other hand, we find that ${\cal B} ( B_c^{\ast+} \to B^+ ϕ) = ( 7.0 \pm 3.0 ) \times 10 ^{-9} $, which is also feasible to be measured at the forthcoming experiments at HL-LHC and FCC-hh.

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arXiv2022

Light baryonium spectrum

We evaluate the light baryonium spectrum, viz. the baryon-antibaryon states, in the framework of QCD sum rules. The nonperturbative contributions up to dimension 12 are taken into account. Numerical results indicate that there might exist eight possible light baryonium states, i.e. $p$-$\bar{p}$, $Λ$-$\barΛ$, $Σ$-$\barΣ$, and $Ξ$-$\barΞ$ with quantum numbers of $0^{-+}$ and $1^{--}$. For the $Λ$-$\barΛ$, $Σ$-$\barΣ$, and $Ξ$-$\barΞ$ states, their masses are found above the corresponding dibaryon thresholds, while the masses of $p$-$\bar{p}$ states are not. The possible baryonium decay modes are analyzed, which are hopefully measurable in BESIII, BELLEII, and LHCb experiments.

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arXiv2021

Gluonic Tetracharm Configuration of $X(6900)$

Recently, a new hadronic structure at around $6.9$ GeV was observed in an LHCb experiment. From its limited yet known decay mode, one could still determine that it contains at least four charm quarks and hence belongs to the category of exotic state. This finding indicates for the first time the tetracharm exotic states and is therefore quite importance. In this letter, we propose a nature hybrid interpretation for the structure of $X(6900)$, i.e. in $[\bar{3}_c]_{c c}\otimes[8_c]_{G}\otimes[3_c]_{\bar{c} \bar{c}}$ configuration with $J^{PC}=0^{++}$, and by using the QCD Sum Rule technique we performed mass spectrum calculation. The results showed that the observed $X(6900)$ could be a gluonic tetracharm state, and some other structures may exist, e.g., one around $7.2$ GeV in the tetracharm hybrid configuration and with $J^{PC}=0^{-+}$. We also predict the tetrabottom hybrid states, leaving for future experiment.

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arXiv2021

Finding $B_c(3S)$ States via Their Strong Decays

The experimentally known $B_c$ states are all below open bottom-charm threshold, which experience three main decay modes, and all induced by weak interaction. In this work, we investigate the mass spectrum and strong decays of the $B_c(3S)$ states, which just above the threshold, in the Bethe-Salpeter formalism and $^3P_0$ model. The numerical estimation gives $M(B_c(3^1S_0))=7273\ {\rm MeV}$, $M(B_c^*(3^3S_1))=7304\ {\rm MeV}$, $Γ\left(B_c(3^1S_0)\to B^*D\right)=26.02^{+2.33}_{-2.21}\ {\rm MeV}$, $Γ\left(B_c^*(3^3S_1)\to BD\right)=3.39^{+0.27}_{-0.26}\ {\rm MeV}$, $Γ\left(B_c^*(3^3S_1)\to B^*D\right)=14.77^{+1.40}_{-1.33}\ {\rm MeV}$ and $Γ\left(B_c^*(3^3S_1)\to BD^*\right)=6.14^{+0.58}_{-0.54}\ {\rm MeV}$. Compared with previous studies in non-relativistic approximation, our results indicate that the relativistic effects are notable in $B_c(3S)$ exclusive strong decays. According to the results, we suggest to find the $B_c(3S)$ states in their hadronic decays to $B$ and $D$ mesons in experiment, like the LHCb.

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arXiv2020

About the exotic structure of $Z_{cs}$

Very recently a new hadronic structure around $3.98$ GeV was observed in BESIII experiment. From its decay modes, it is reasonable for people to assign it to the category of exotic state, say $Z^+_{cs}$, the stranged-parter of $Z_{c}(3900)$. This finding indicates for the first time the exotic state with strange quark in charm sector, and hence has a peculiar importance. By virtue of the QCD Sum Rule technique, we analyze the $Z^+_{cs}$ about its possible configuration and physical properties, and find it could be configured as a mixture of two types of structures, $[1_c]_{\bar{c} u}\otimes[1_c]_{\bar{s} c}$ and $[1_c]_{\bar{c} c}\otimes[1_c]_{\bar{s} u}$, or $[3_c]_{\bar{c} u}\otimes[\bar{3}_c]_{\bar{s} c}$ and $[3_c]_{\bar{c} c}\otimes[\bar{3}_c]_{\bar{s} u}$, with $J^P=1^+$. Physically, it then appears to be the emergence of a compound of four possible currents in each configuration, which tells the single current evaluation of hadron spectroscopy and their decay properties are sometimes not enough. We find in both cases the energy spectra may fit well with the experimental observation, i.e. $3.98$ GeV, within the uncertainties, while noted the former is not favored by vector meson exchange model. Various $Z^+_{cs}(3980)$ decay modes are evaluated, which are critical for pinning down its configuration and left for experimental verification. We also predict the mass of $Z^0_{cs}$, the neutral partner of $Z^+_{cs}(3980)$, and analyze its dominant decay probabilities.

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arXiv2020

Gluon-pair-Creation Production Model of Strong Interaction Vertices

By studying the $η_c$ exclusive decay to double glueballs, we introduce a model to mimic phenomenologically the gluon-pair-vacuum interaction vertices, namely the $0^{++}$ model. Based on this model, we study glueball production in pseudoscalar quarkonium decays, explicitly $η_c \to f_0(1500)η(1405)$, $η_b\to f_0(1500)η(1405)$ and $η_b\to f_0(1710)η(1405)$ processes. Among them $f_0(1500)$ and $f_0(1710)$ are well-known scalars possessing large glue components and $η(1405)$ is a potential candidate for pseudoscalar glueball. The preliminary calculation results indicate that these processes are marginally accessible in the presently running experiments BES III, BELLE II, and LHCb.

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arXiv2020

Hidden-bottom and -charm hexaquark states in QCD sum rules

In this paper, we investigate the spectra of the prospective hidden-bottom and -charm hexaquark states with quantum numbers $J^{PC }= 0^{++}$, $0^{-+}$, $1^{++}$ and $1^{--}$ in the framework of QCD sum rules. By constructing appropriate interpreting currents, the QCD sum rules analyses are performed up to dimension 12 of the condensates. Results indicate that there exist two possible baryonium states in $b$-quark sector with masses $11.84 \pm 0.22$ GeV and $11.72 \pm 0.26$ GeV for $0^{++}$ and $1^{--}$, respectively. The corresponding hidden-charm partners are found lying respectively at $5.19 \pm 0.24$ GeV and $4.78 \pm 0.23$ GeV. Note that these baryonium states are all above the dibaryon thresholds, which enables their dominant decay modes could be measured at BESIII, BELLEII, and LHCb detectors.

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