Related papers: Multiquark states and QCD sum rules
In this research, we tentatively assign the $T_{c\bar{s}}(2900)$ as the $A\bar{A}$-type tetraquark state, and study the mass spectrum of the tetraquark states with strange and doubly strange, which have the spin-parity $J^P = 0^+$, $1^+$…
Recent observations by Belle and BESIII of charged quarkonium-like resonances give new stimulus for theoretical investigation of exotic hadrons in general and heavy tetraquarks in particular. We use QED_2, a confining theory, as a model for…
In this work, we systematically investigate the singly-charmed pentaquark molecular states $D^{(*)}N$, $D^{(*)}\Xi^{(*)}$ and $D_s^{(*)}\Xi^{(*)}$ with the QCD sum rules by carrying out the operator product expansion up to the vacuum…
We discuss a possible interpretation of the f0(980) meson as a hadronic molecule - a bound state of K and bar K mesons. Using a phenomenological Lagrangian approach we calculate the strong f0(980) to pi pi and electromagnetic f0(980) to…
QCD sum rules are overviewed with an emphasize on the practical applications of this method to the physics of light and heavy hadrons.
In this article, we construct the color-singlet-color-singlet type currents and the color-singlet-color-singlet-color-singlet type currents to study the scalar $D^*\bar{D}^*$, $D^*D^*$ tetraquark molecular states and the vector…
Within the past ten years many new hadrons states were observed experimentally, some of which do not fit into the conventional quark model. I will talk about the few-body systems composed of heavy quarks, including the charmonium-like…
In this article, we take the pseudoscalar, scalar, axialvector, vector, tensor (anti)diquark operators as the basic constituents, and construct the scalar, axialvector and tensor tetraquark currents to study the mass spectrum of the ground…
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…
We present a compact review of the status of QCD spectral sum rules until 2022. We emphasize the recent progresses for determining the QCD input parameters ($\alpha_s$, running quark masses, quark and gluon condensates) where their…
The mass, current coupling, and width of the doubly charmed four-quark meson $T_{cc}^{+}$ are explored by treating it as a hadronic molecule $ M_{cc}^{+}\equiv D^{0}D^{\ast +}$. The mass and current coupling of this molecule are calculated…
In this article, we study the masses and pole residues of the pseudoscalar-diquark-pseudoscalar-antidiquark type and vector-diquark-vector-antidiquark type scalar hidden-charm $cu\bar{c}\bar{d}$ ($cu\bar{c}\bar{s}$) tetraquark states with…
We report our recent work on a hadronic molecule state of the KbarKN system with I=1/2 and J^P=1/2^+. We assume that the Lambda(1405) resonance and the scalar mesons, f_{0}(980), a_{0}(980), are reproduced as quasi-bound states of KbarN and…
This is the first study on the double-gluon hybrid, which consists of one valence quark and one valence antiquark together with two valence gluons. We concentrate on the one with the exotic quantum number $J^{PC} = 2^{+-}$ that conventional…
In this article, we study the doubly heavy baryon states $\Xi_{cc}$, $\Omega_{cc}$, $\Xi_{bb}$ and $\Omega_{bb}$ in the nuclear matter using the QCD sum rules, and derive three coupled QCD sum rules for the masses, vector self-energies and…
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…
We review the recent status of the QCD sum rule approach to study the properties of hadrons in vacuum and in hot or dense matter. Special focus is laid on the progress made in the evaluation of the QCD condensates, which are the input of…
In this work, we construct the color-singlet-color-singlet type six-quark pseudoscalar current to investigate the $\overline{\Xi}_{cc}\Xi_{cc}$ hexaquark molecular state with the QCD sum rules, the predicted mass $M_X \sim 7.2\,\rm{GeV}$…
We propose a new QCD sum rule analysis for the Lambda(1405) and the Sigma(1620). Using the I=0 and I=1 multiquark sum rules we predict their masses.
In this article, we construct the axialvector-diquark-scalar-antidiquark type currents to interpolate the axialvector doubly heavy tetraquark states, and study them with the QCD sum rules in details by carrying out the operator product…