Related papers: The new $a_1(1420)$ state: structure, mass and wid…
The mass and coupling of the axial-vector tetraquark $T_{bc;\bar{u}\bar{d} }^{0}$ (in a short form $T_{bc}^{0}$) are calculated by means of the QCD two-point sum rule method. In computations we take into account contributions arising from…
We apply the QCD sum rule method to systematically study excited light meson operators and calculate their decay constants. These operators are constructed by explicitly adding one covariant derivative to the quark-antiquark pair. In total,…
We calculate the mass spectrum of the $Qs\bar q \bar q$ $(Q=c, b)$ tetraquark states with $J^P=(0,1,2)^+$ using the AL1 quark potential model, which successfully describes the conventional hadron spectrum. We employ the Gaussian expansion…
We are systematically studying the electromagnetic characteristics of multiquark systems to shed light on their internal structure, whose nature and quantum numbers are controversial. In this study, we investigate the magnetic dipole,…
To shed light on the properties of states whose nature, internal structure, and spin-parity quantum numbers are not fully elucidated, we systematically study their electromagnetic properties. In light of this concept, we present a…
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…
We study the possible spin-1 charmonium-like states by using QCD sum rule approach. We calculate the two-point correlation functions for all the local form tetraquark interpolating currents with $J^{PC}=1^{--}, 1^{-+}, 1^{++}$ and $1^{+-}$…
Inspired by the recent experimental progress on the $T_{c\bar{s}0}^a(2900)^{0/++}$, the fully open tetraquark spectrum with the configuration of $[8]_{[c\bar{s}]} \otimes [8]_{[q \bar{q^\prime}]}$ is systematically investigated by the QCD…
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…
Stimulated by the observation of $\Lambda_c(2910)^+$ by the Belle Collaboration, the $S$-wave $qqq\bar{q}c~(q=u~\text{or}~d)$ pentaquark systems with $I$ = 0, $J^P$ = $\frac{1}{2}^-,~\frac{3}{2}^- and~\frac{5}{2}^-$ are investigated in the…
In this work, we extend our previous work on the $D^*\bar{D}^*$ molecular states with the $J^{PC}=0^{++}$, $1^{+-}$ and $2^{++}$ to investigate their two-body strong decays via the QCD sum rules based on rigorous quark-hadron duality. We…
In this work, we take the $X(3872)$ as the hidden-charm tetraquark state with both isospin $I=0$ and $1$ components, then investigate the strong decays $X(3872)\to J/\psi \pi^+\pi^-$, $J/\psi\omega$, $\chi_{c1}\pi^0$, $D^{*0}\bar{D}^0$ and…
Using a soft-wall AdS/QCD approach we derive the Schr\"odinger-type equation of motion for the tetraquark wave function, which is dual to the dimension-4 AdS bulk profile. The latter coincides with the number of constituents in the leading…
We study the $\sigma$ meson in QCD sum rules using a two quark interpolating field with derivatives. In the constituent quark model, the $\sigma$ meson is composed of a quark and an antiquark in the relative p-wave state and is thus…
We study the mass spectra of D-wave excited $cs\bar{c}\bar{s}$ tetraquark states with $J^{PC}=1^{++}$ and $1^{+-}$ in both symmetric $\mathbf{6}_{cs}\otimes\bar{\mathbf{6}}_{\bar{c}\bar{s}}$ and antisymmetric…
In this article, we calculate the contributions of the vacuum condensates up to dimension-10 in the operator product expansion, and study the $C\gamma_\mu-C\gamma_\nu$ type scalar, axial-vector and tensor tetraquark states in details with…
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^{++})}…
We have investigated the $qss\bar{q}q$ ($q = u$ or $d$) system to find possible pentaquark explanations for the $\Xi$ resonances. The bound state calculation is carried out within the framework of the quark delocalization color screening…
Using the QCD sum rules approach we study the mass and decay width of the channel $J/\psi + \omega$ for the $Y(3940)$ state. We assume that it can be described by a mixed charmonium-molecule scalar state, $(\chi_{c0})-(D^\ast D^\ast)$…
Global fits to the shape of the first QCD Laplace sum rule exhibiting sensitivity to pion-resonance [$\Pi (1300)$] parameters are performed, leading to predictions for the pion-resonance mass and decay constant. Two scenarios are considered…