Related papers: $X(3872)$, $X_b$, and the $\chi_{b1}(3P)$ state

The X(3872) is studied as an axial-vector charmonium state in the multichannel framework of the Resonance-Spectrum-Expansion quark-meson model, previously applied to a variety of other puzzling mesonic resonances. Included are the…

It has been argued that the mystery boson X(3872) is a molecule state consisting of primarily D0-D0*bar + D0bar-D*0. In contrast, apparent puzzles and potential difficulties have been pointed out for the charmonium assignment of X(3872). We…

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…

All existing experimental evidence of the bound state nature of the $X(3872)$ relies on considering its decay products with a finite experimental spectral mass resolution which is typically $\Delta m \ge 2 $MeV and much larger than its…

We study the bottomonium spectrum in the nonrelativistic quark model with the coupled-channel effects. The mass shifts and valence $b\bar{b}$ component are evaluated to be rather large. We find that the hadronic loop effects can be…

We report results from a study of hadronic transitions of the $\chi_{bJ}(nP)$ states of bottomonium at Belle. The $P$-wave states are reconstructed in transitions to the $\Upsilon(1S)$ with the emission of an $\omega$ meson. The transitions…

We predict the existence of two novel bottomoniumlike states, $Y(10600)$ and $Y(10650)$, as either the $P$-wave $B^{(*)}\bar{B}^{(*)}$ bound state or resonance close to the $B\bar{B}^{*}$ and $B^{*}\bar{B}^{*}$ thresholds, respectively,…

The nature of the bottomonium-like states $Z_b(10610)$ and $Z_b(10650)$ is studied by calculating the $B^{(*)}\overline B^{*}$ compositeness ($X$) in those resonances. We first consider uncoupled isovector $S$-wave scattering of…

Several charmonium-like states above $D\bar{D}$ threshold have been discovered at the Belle and BABAR B-factories. Some of these states are produced via Initial State Radiation (e.g. Y(4260) and Y(4350)), and some are observed in B-meson…

We demonstrate that the dip observed near the total energy of 3872 MeV in the recent cross section data from the BESIII Collaboration for $e^+e^-\to J/\psi\pi^+\pi^- $ admits a natural explanation as a coupled-channel effect: it is a…

We study the $\Xi_b(6100)$ using the methods of QCD sum rules and light-cone sum rules within the framework of heavy quark effective theory. Our results suggest that the $\Xi_b(6100)$ can be well interpreted as the $P$-wave bottom baryon of…

The $X(3872)$ is investigated by employing the quark-hadron hybrid model, that consists of the $c\bar c$ core, $D^{(*)}\bar D{}^*$, $J/\psi\omega$, and $J/\psi\rho$ two-meson states. Due to the attraction from the $c\bar c$-$D\bar D{}^*$…

We present studies in bottomonium spectroscopy carried out with samples of $(98\pm1)$ million $\Upsilon(2S)$ and $(121\pm1)$ million $\Upsilon(3S)$ events recorded with the BaBar detector at the PEP-II asymmetric-energy $e^+ e^-$ collider…

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…

Recently, several charmonium-like states above $D\bar{D}$ threshold have been discovered at the BELLE and BABAR $B$-factories. Some of these states are produced via Initial State Radiation ({\it e.g.} Y(4260) and Y(4350)) and some are…

More than twenty years have elapsed since the discovery of $\chi_{c1}(3872)$ (previously denoted as $X(3872)$), and an impressive amount of theoretical and experimental studies has been devoted to its properties, decays and production…

We consider the transitions from the $Z_b(10610)$ and $Z_b(10650)$ resonances to the states of bottomonium with emission of a pion. The $Z_b$ resonances are viewed as `molecular' objects of a large spatial size made of heavy $B^{(*)}$…

A study of the lineshape of the $\chi_{c1}(3872)$ state is made using a data sample corresponding to an integrated luminosity of $3\,$fb$^{-1}$ collected in $pp$ collisions at centre-of-mass energies of 7 and 8\,TeV with the LHCb detector.…

This Letter presents a search for a hidden-beauty counterpart of the $X(3872)$ in the mass ranges 10.05--10.31 GeV and 10.40--11.00 GeV, in the channel $X_b \to \pi^{+} \pi^{-} \Upsilon(1 \rm S)(\rightarrow\mu^+\mu^-)$, using 16.2 fb$^{-1}$…

We discuss the possibility that the X(3872) can be a $D\bar{D}^*$ molecular bound state in the Bethe-Salpeter equation approach in the ladder and instantaneous approximations. We show that the $D\bar{D}^*$ bound state with quantum numbers…