Related papers: Pseudoscalar and vector tetraquarks $bb\overline{c…
We present a review of our results for the masses and couplings of the scalar fully heavy four-quarks and $T_{QQ\bar{q}\bar{q}'}\, (J^P=0^\pm , 1^\pm)$ tetraquarks states from QCD Laplace sum rule (LSR), their ratios ${\cal R}$ and double…
We study semileptonic decays of the scalar tetraquark $Z_{bc;\overline{u} \overline{d}}^{0}$ to final states $T_{bs;\overline{u}\overline{d} }^{-}e^{+}\nu_{e}$ and $T_{bs;\overline{u}\overline{d}}^{-}\mu^{+}\nu_{\mu}$ , which run through…
We apply the method of QCD sum rules to study the $s s \bar s \bar s$ tetraquark states of $J^{PC} = 0^{-+}$. We construct all the relevant $s s \bar s \bar s$ tetraquark currents, and find that there are only two independent ones. We use…
We suppose that there exist three vector hidden-charm tetraquark states with the $J^{PC}=1^{--}$ at the energy about $4.5\,\rm{GeV}$, and investigate the two-body strong decays systematically. We obtain thirty QCD sum rules for the hadronic…
Temperature dependences of masses and current couplings of the ground state of the fully heavy tetraquarks $T_{4c}$ and $T_{4b}$, composed of charm $(c)$ and bottom $(b)$ quarks and antiquarks with spin-parities $J^{PC} = 0^{++}$ are…
In this article, we introduce a P-wave between the diquark and antidiquark explicitly to construct the vector tetraquark currents, and study the vector tetraquark states with the QCD sum rules systematically, and obtain the lowest vector…
In this article, we construct the $C \otimes \gamma_\mu C$ and $C\gamma_5 \otimes \gamma_5\gamma_\mu C$ type currents to interpolate the vector tetraquark states, then carry out the operator product expansion up to the vacuum condensates of…
We investigate the pseudoscalar ($\eta_t$) and vector ($\psi_t$) toponium states, as well as the triply-top baryon ($\Omega_{ttt}$), using the QCD sum-rule method. This study was motivated by the recent observation of a pseudoscalar…
In this work, we study the properties of the pseudoscalar hidden-charm tetraquark states by analyzing their two-body strong decays via the QCD sum rules based on rigorous quark-hadron duality. We take into account the vacuum condensates up…
The mass and meson-current coupling of the diquark-antidiquark states with the quantum numbers $J^{P}=0^{+}$ and quark contents $Z_{q}=[cq][\bar {b} \bar q ]$ and $Z_{s}=[cs][\bar {b} \bar s]$ are calculated using two-point QCD sum rule…
In the present work, we investigate the scalar, axialvector and tensor doubly-charmed tetraquark molecular states without strange, with strange and with doubly-strange via the QCD sum rules, and try to make assignment of the $T^+_{cc}$ from…
We perform a QCD sum rule study of the open-charmed $D_s (2317)$ as a four-quark state. Using the diquark-antidiquark picture for the four-quark state, we consider four possible interpolating fields for $D_s (2317)$, namely, scalar-scalar,…
In this article, we perform a systematic study of the mass spectrum of the vector hidden charmed and bottomed tetraquark states using the QCD sum rules.
Decays of the fully beauty four-quark structures $X_{\mathrm{4b}}$ and $T_{ \mathrm{4b}}$ to $B$ meson pairs are investigated in the framework of QCD three-point sum rule method. We model the scalar exotic mesons $X_{\mathrm{4b }}$ and…
In this article, we introduce a relative P-wave to construct the doubly-charm axialvector diquark operator, then take the doubly-charm axialvector (anti)diquark operator as the basic constituent to construct the scalar and tensor tetraquark…
In this article, we take the $Y(4260/4220)$ as the vector tetraquark state with $J^{PC}=1^{--}$, and construct the $C\gamma_5\otimes\stackrel{\leftrightarrow}{\partial}_\mu\otimes \gamma_5C$ type diquark-antidiquark current to study its…
In this article, we distinguish the charge conjugations of the interpolating currents, calculate the contributions of the vacuum condensates up to dimension-10 in the operator product expansion, and study the masses and pole residues of the…
In this article, we study the $J^{PC}=0^{++}$ and $2^{++}$ $QQ\bar{Q}\bar{Q}$ tetraquark states with the QCD sum rules, and obtain the predictions $M_{X(cc\bar{c}\bar{c},0^{++})} =5.99\pm0.08\,\rm{GeV}$, $M_{X(cc\bar{c}\bar{c},2^{++})}…
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…
Motivated by the enigmatic vector charmonium-like states, we investigate the strong decay behaviors of four kinds of vector tetraquark states, which are possible candidates for the $Y(4660)$, within the framework of three-point QCD sum…