Related papers: Investigations on the weak decays of $D\bar{B}$ mo…

We propose to search for the open heavy-flavor exotic states with the quark components of $Qs\bar u\bar d$ with $Q=b,c$ via their weak decays. If there exist such exotic states below the $BK$ or $DK$ thresholds, they can only decay weakly.…

We perform a theoretical study of the decay process $\Upsilon \to D^{-} \bar{B}^{0} D_s^{+}$ in search of the doubly heavy tetraquark states $T_{bc\bar{s}}$ with quark content $bc\bar{s}\bar{d}$. These $T_{bc\bar{s}}$ states are assumed to…

Within the framework of QCD sum rules, we have investigated the tetraquark states with three heavy quarks. We systematically construct the interpolating currents for the possible $cc\bar{c}\bar{q}$, $cc\bar{b}\bar{q}$, $bc\bar{b}\bar{q}$,…

In the framework of the color-magnetic interaction, we systematically investigate the mass splittings of the $QQ\bar{Q}\bar{q}$ tetraquark states and estimated their rough masses in this work. These systems include the explicitly exotic…

Treating the $X(4140)$ as a compact $J^{PC}=1^{++}$ $cs\bar{c}\bar{s}$ state and using its mass as a reference scale, we systematically estimate the masses of doubly heavy tetraquark states $QQ\bar{q}\bar{q}$ where $Q=c,b$ and $q=u,d,s$.…

In the present work, we investigate the productions of the molecular states composed of $D^{(*)}_s \bar{D}^{(*)}$ and $D^{(*)}_s \bar{D}^{(*)}_s$ in the $B$ and $B_s$ decays by using an effective Lagrangian approach. The branching ratios in…

In the light of the recent discovery of the $\Xi^{++}_{cc}$ by LHCb collaboration, we study the stable doubly heavy tetraquarks. These states are compact exotic hadrons which can be approximated as the diquark-anti-diquark correlations. In…

In decay modes $B^0 \to D_s^{(*)+} D_s^{(*)-}$ and $B_s^0 \to D^{(*)+} D^{(*)-}$, none of quarks in final states is the same as one of $B$ meson. They can occur only via annihilation diagrams in the Standard Model. In the heavy quark limit,…

The $\bar{B}_{q}^{\ast}$ ${\to}$ $DP$, $DV$ weak decays are studied with the perturbative QCD approach, where $q$ $=$ $u$, $d$ and $s$; $P$ and $V$ denote the ground $SU(3)$ pseudoscalar and vector meson nonet. It is found that the…

Motivated by the recently observation of the tetraquark $T_{cc}^+ $ state, in this work I revisit the Heavy-Meson Effective Theory to perform a simplified field-theoretical study of possible deuteron-like $D^{(\ast)} D ^{(\ast)},…

Recently, several exotic bosons have been confirmed as multi-quark states, but there are violent disputes about their inner structures, namely if they are molecular states or tetraquarks, or even mixtures of the two structures. It would be…

The recently discovered tetraquark, $T_{cc}^+$, has quark content $cc\bar{u}\bar{d}$ and a mass that lies just below open charm thresholds. Hence it is reasonable to expect the state to have a significant molecular component. We calculate…

The weak decays of the axial-vector tetraquark $T_{bb;\bar{u} \bar{d}}^{-}$ to the scalar state $Z_{bc;\bar{u} \bar{d}}^{0}$ are investigated using the QCD three-point sum rule approach. In order to explore the process $T_{bb; \bar{u}…

In the framework of the improved chromomagnetic interaction model, we complete a systematic study of the $S$-wave tetraquark states $Qq\bar{Q}\bar{q}$ ($Q=c,b$, and $q=u,d,s$) with different quantum numbers, $J^{PC}=0^{+(+)}$, $1^{+(\pm)}$,…

The decay behavior of an exotic state can be used to probe its internal structure. We note that the hidden-charm pentaquark states, $P_{\psi}^{N}(4312)$, $P_{\psi}^{N}(4440)$, and $P_{\psi}^{N}(4457)$, have only been observed in the $J/\psi…

The $D_s(2320)$ state recently observed by BaBar in the $D_s^+\pi^0$ channel may be the first of a host of $cq\bar q\bar q$ four-quark states. We give a phenomenological account of the masses and decay modes. The isosinglet $D_s(2320)$…

We relate the interactions of the $\bar{D}^{(\ast)} K^\ast$ and $D^{(\ast)} K^\ast$ systems to those of $D^{(\ast)}D^{(\ast)}$ and $D^{(\ast)}\bar{D}^{(\ast)}$ respectively, considering the residual strong interactions at the near-threshold…

The observation of $X_0(2900)$ in $B^+\rightarrow D^+D^-K^+$ decay process indicates the existence of open flavor tetraquark states. We study the production and decay of $X_0(2900)$ state with final state interaction mechanism, where we…

We have studied the strong decay properties of the recently observed $T^a_{c\bar s0}(2900)^{++/0}$ by considering it as a $cu\bar{d}\bar{s}/cd\bar{u}\bar{s}$ fully open-flavor tetraquark state with $I(J^P)=1(0^+)$. In the framework of QCD…

Motivated by the discovery of several charm states exhibiting tetraquark-like characteristics at BESIII and LHCb, this study investigates the spectroscopy and decay properties of D mesons and tetraquark states with quark content…