Related papers: Internal structure of $T_{cc}$ and $X(3872)$ by us…
The near-threshold exotic hadrons such as $T_{cc}$ and $X(3872)$ are naively considered as the hadronic molecular state from the viewpoint of the low-energy universality. However, it is also known that the elementary dominant state is not…
The compositeness of weakly bound states is discussed using the effective field theory from the viewpoint of the low-energy universality. We introduce a model with coupling of the single-channel scattering to the bare state, and study the…
We study the internal structure of exotic hadrons, especially focusing on the relation between the compositeness and physical observables. Defined as the probability of finding hadronic molecular components in the wave function,…
In this work, we propose a new method to detect the composition of the $X(3872)$ state. Based on a widely accepted interpretation that $X(3872)$ is a weakly bound $S$-wave molecule of the $D^{*0} \bar{D}^{0}$ (neutral) and $D^{*+} D^{-}$…
The nature of the $X(3872)$ and other exotic hadrons has been a subject of extensive investigation since the first observation of the $X(3872)$ in 2003. While various theoretical models have been proposed, including hadronic molecular and…
In order to understand the structure of the X(3872), the $c \bar c$ charmonium core state coupling to the $D^0 \bar D^{\ast 0}$ and $D^+ D^{\ast -}$ molecular states are studied. The strengths of the couplings between the charmonium state…
The nature of the $X(3872)$ and other exotic hadrons has been a subject of extensive investigation. While various theoretical models have been proposed, experimental evidence suggests that the $X(3872)$ may be a mixture state of a hadronic…
It is pointed out that the internal structure of the narrow resonance X(3872) at the D^0 {\bar D}^{*0} threshold can be studied in some detail by measuring the rate and the spectra in the decays X(3872) \to D^0 {\bar D}^0 \pi^0 and X(3872)…
We argue why the recently observed $T_{cc}$ could either be a compact multiquark configuration or a loosely bound molecular configuration composed of charmed mesons, whereas the $X(3872)$ is most likely a molecular configuration. The…
We have investigated the internal structure of the open- and hidden-charmed ($DD^*$/$\bar DD^*$) molecules in the unified framework. We first fit the experimental lineshape of the $T^+_{cc}$ state and extract the $DD^*$ interaction, from…
We investigate hidden-charm exotic mesons based on a coupled-channel framework, where the physical states are described as superpositions of a compact $c\bar c$ core (identified with the $\chi_{cJ}(2P)$ states) and hadronic components such…
We have performed a coupled channel calculation of the $1^{++}$ $c\bar c$ sector including $q\bar q$ and $DD^*$ molecular configurations. The calculation was done within a constituent quark model which successfully describes the meson…
The concept of compositeness is used to quantitatively discuss the hadronic molecular nature in exotic hadrons. In this work, we develop a formulation to explicitly introduce the compact quark state contribution in the hadronic potentials…
Recent observations of exotic hadrons have stimulated the theoretical investigation of the internal structure of hadrons. While all hadrons are ultimately composed of quarks and gluons bound by the strong interaction, quark clustering…
Inspired by that Belle\uppercase\expandafter{\romannumeral2} Collaboration recently reported $T_{cc}$, which can be interpreted as a molecular $DD^{*}$, we investigated the trihadron system of $T_{cc}$ partner with $IJ^{P}$=$01^{-}$ in the…
The internal structure of exotic hadron candidates are studied from the viewpoint of the compositeness of near-threshold states. We focus on the Weinberg's weak-binding relation between the experimental observables and the compositeness of…
In 2021, LHCb collaboration reported a very narrow state in the $D^0D^0\pi^+$ mass spectrum just below the $D^{*+}D^0$ mass threshold. We consider the influence of the Castillejo-Dalitz-Dyson (CDD) pole in the scattering amplitude to derive…
The exploration of energies above the open-flavor threshold in the meson spectra has led to the appearance of unexpected states difficult to accommodate in the naive picture of a bound state of a quark and an antiquark. Many of such states…
A central question in exotic-hadron physics is their internal structure whether these states are loosely bound hadronic molecules or compact multiquark configurations. To shed light on this issue, we develop a model that incorporates mixing…
Using chiral effective field theory, we predict that there must be isovector charmonium-like $D\bar D^*$ hadronic molecules with $J^{PC}=1^{++}$ denoted as $W_{c1}$. The inputs are the properties of the $X(3872)$, including its mass and the…