Related papers: Short Range Structure in the X(3872)
Spectroscopy results for Belle and BaBar are reported. A particular focus is put on new results of the X(3872) state with its radiative decays to $J$/$\psi$$\gamma$ and $\psi'$$\gamma$, its decay into $J$/$\psi$3$\pi$ and the search for…
Exotic charmonium-like states have been observed by various experiments over the last 15 years, but their nature is still under discussion. Photo-(muo)production is a new promising instrument to study them. COMPASS, a fixed target…
We introduce a near-threshold parameterization that is more general than the effective-range expansion up to and including the effective-range because it can also handle with a near-threshold zero in the $D^0\bar{D}^{*0}$ $S$-wave. In terms…
In the present article we report on evidence for hadronic molecule structures in the charmonium sector. In particular we discuss the Y(3940) and the recently observed Y(4140) as heavy hadron molecule states with quantum numbers $J^{PC} =…
The $\Lambda_c(2940)$, an open-charm baryon discovered in 2006, has sparked interest due to its ``low mass puzzle'', paralleling the $X(3872)$ in the charmoniumlike sector. Both states challenge conventional hadronic interpretations, with…
The composite nature of a shallow bound state is studied by using the weak-binding relation, which connects the compositeness of the bound state with observables. We first show that the previous weak-binding relation cannot be applied to…
Monte-Carlo simulations for a resonance scan of the charmonium-like state X(3872) at Panda are performed. Final state radiation hadronic background reactions are taken into account. The signal reconstruction uses a realistic pattern…
Inspired by the recent observation of $\chi_{c0}(3930)$, $X(4685)$ and $X(4630)$ by the LHCb Collaboration and some exotic resonances such as $X(4350)$, $X(4500)$, etc. by several experiment collaborations, the $cs\bar{c}\bar{s}$ tetraquark…
In this work the production of the state $X(3872)$ is estimated via the reaction $B^0 \to K^{\ast 0} X(3872)$ through triangle mechanisms described by the sequence $B^0 \to D_s^{(*)+} (\to K^{\ast 0} D^{(*)+} ) \ D^{(*)-} \to K^{\ast 0} \ (…
Two near-threshold peaking structures with spin-parities $J^{\mathrm{PC} }=0^{++}$ were recently discovered by the LHCb Collaboration in the $ D_{s}^{+}D_{s}^{-}$ invariant mass distribution of the decay $ B^{+}\rightarrow…
The X(3872) has non-charmonium-like properties, such as decay processes that seem to violate isospin, and a mass that lies unexpectedly close to the neutral-D-plus-neutral-D-excited-state threshold. An EFT that includes both charmonium-like…
We present recent studies of charmonium multiquark states. We use different interacting models and numerical methods to study deeply bound four-quark states and meson-meson molecules. No deeply bound four-quark states are found in our…
Recently, the new structure $G(3900)$ observed by the BESIII Collaboration in the $e^+e^-\to D\bar{D}$ was identified to be the $P$-wave $D\bar{D}^\ast/\bar{D}D^\ast$ vector molecular resonance using a unified meson exchange model. Apart…
We developed a Friedrichs-model-like scheme in studying the hadron resonance phenomenology and present that the hadron resonances might be regarded as the Gamow states produced by a Hamiltonian in which the bare discrete state is described…
We have studied isospin breaking effects in the X(3872) resonance and found a natural explanation for the branching fraction of the X decaying to $J/\psi$ with two and three pions being close to unit. Within our framework the X(3872) is a…
In this paper, the new particle $X(3842)$ discovered by the LHCb Collaboration is identified to be the $\psi_{_3}(1^3D_{_3})$ state. We study its strong decays with the combination of the Bethe-Salpeter method and the $^3P_{_0}$ model. Its…
The $\chi_{c1}(3872)$ serves as a pivotal role for understanding hadronic structures, remaining one of the most extensively studied exotic particles despite the experimental discovery of numerous unconventional hadronic states. Sustained…
A recent quark-model description of X(3872) as an unquenched $2\,{}^{3\!}P_1$ $c\bar{c}$ state is generalised by now including all relevant meson-meson configurations, in order to calculate the widths of the experimentally observed…
We present results of a search for the X(3872) in B0-->X(3872)KS0,X(3872)-->J/psi pi+ pi-, improved measurements of B-->X(3872)K-, and a study of the J/psi pi+ pi- mass region above the X(3872). We use 232x106 B[overline B] pairs collected…
If the recently-discovered charmonium-like state X(3872) is a loosely-bound S-wave molecule of the charm mesons D^0 \bar D^{*0} or D^{*0} \bar D^0, it can be produced through the weak decay of the B meson into D^0 \bar D^{*0} K or D^{*0}…