Related papers: The new $a_1(1420)$ state: structure, mass and wid…

The scalar tetraquarks $T_{b}$ and $T_{c}$ with asymmetric contents $bb \overline{b}\overline{c}$ and $cc \overline{c}\overline{b}$ are explored using the QCD sum rule method. These states are modeled as the diquark-antidiquarks composed of…

We evaluate the mass of the $B_{s0}$ scalar meson and the coupling constant in the $B_{s0} B K$ vertex in the framework of QCD sum rules. We consider the $B_{s0}$ as a tetraquark state to evaluate its mass. We get $m_{B_s0}=(6.04\pm 0.08)…

The masses, current couplings and widths of the fully heavy scalar tetraquarks $X_{\mathrm{4Q}}=QQ\overline{Q}\overline{Q}$, $Q=c, b$ are calculated by modeling them as four-quark systems composed of axial-vector diquark and antidiquark.…

We study a hypothetical $\Delta^0\Delta^0$ dibaryon state by means of QCD sum rule method. We construct a scalar interpolating current to extract the mass and decay constant of this state taking into account contributions of various quark,…

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…

The $a_1(1420)$ with $I^G(J^{PC})= 1^-(1^{++})$ observed in the $\pi^+ f_0(980)$ final state in the $\pi^-p\to \pi^+\pi^-\pi^- p$ process by the COMPASS collaboration seems unlikely to be an ordinary $\bar qq$ mesonic state. Available…

Investigation of the resonances $X(4140)$ and $X(4274)$, which were recently confirmed by the LHCb Collaboration [1], is carried out by treating them as the color triplet and sextet $[cs][\bar{c}\bar {s}]$ diquark-antidiquark states with…

In this work we report on a new QCD sum rule analysis to predict masses of the excited baryon states (e.g. Sigma(1620) and Lambda(1405)) by using multiquark interpolating fields ($(q\bar{q})(qqq)$). For the Sigma(1620) we consider the…

The internal structure of light scalar state $a_0(1450)$ has not been definitively determined, it may consist of multiple possible states. Among them, it has the possibility of being regarded as a diquark state. Based on this possibility,…

The resonance $X(6600)$ is explored as the all-charm tetraquark structure with spin-parities $J^{\mathrm{PC}}=2^{++}$. It is considered in the diquark-antidiquark picture and modeled as a tensor state $X$ composed of the axial-vector…

In this article, we take the $X(4140)$ as the diquark-antidiquark type $cs\bar{c}\bar{s}$ tetraquark state with $J^{PC}=1^{++}$, and study the mass and pole residue with the QCD sum rules in details by constructing two types interpolating…

The mass and width of the tensor tetraquark $T=bb\overline{c}\overline{c}$ with spin-parity $J^{\mathrm{P}}=2^{+}$ are calculated in the context of the QCD sum rule method. The tetraquark $T$ is modeled as a diquark-antidiquark state built…

We have studied the production and decay of the $f_1(1285)$ into $\pi a_0(980)$ and $K^* \bar K$ as a function of the mass of the resonance and find a shoulder around 1400 MeV, tied to a triangle singularity, for the $\pi a_0(980)$ mode,…

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.

We explore features of the scalar structure $X_0(2900)$, which is one of the two resonances discovered recently by LHCb in the $D^{-}K^{+}$ invariant mass distribution in the decay $B^{+} \to D^{+}D^{-}K^{+}$. We treat $ X_0(2900)$ as a…

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,…

We use QCD sum rules to test the nature of the recently observed mesons Y(4260), Y(4350) and Y(4660), assumed to be exotic four-quark $(c\bar{c}q\bar{q})$ or $(c\bar{c}s\bar{s})$ states with $J^{PC}=1^{--}$. We work at leading order in…

We study the exotic $\Delta^{0}\Delta^{0}$ dibaryon state with quantum numbers $J^{P} = 2^{+}$ within the framework of QCD sum rules. A tensor interpolating current is constructed to determine the mass and residue of this state, including…

We study features of the resonances $X(2100)$ and $X(2239)$ by treating them as the axial-vector and vector tetraquarks with the quark content $ss \overline{s}\overline{s}$, respectively. The spectroscopic parameters of these exotic mesons…

We present an analysis of the newly observed pentaquark $P_c(4312)^+$ to shed light on its quantum numbers. To do that, the QCD sum rule approach is used. The measured mass of this particle is close to $\Sigma_c^{++}\bar{D}^-$ threshold and…