Related papers: Interpreting Z(3900)
Very recently the LHCb Collaboration reported their observation of the first two fully open-flavor tetraquark states, the $X_0(2900)$ of $J^P = 0^+$ and the $X_1(2900)$ of $J^P = 1^-$. We study their possible interpretations using the…
The analyses of the LHCb data on $X(6900)$ found in di-$J/\psi$ and $J/\psi \psi(3686)$ systems are performed using a momentum-dependent {Flatt\'{e}}-like parameterization. The use of the pole counting rule and spectral density function sum…
Two recent observations of new b hadrons in pp collisions at \sqrt{s} = 7 TeV at the Large Hadron Collider (LHC) are presented. The ATLAS collaboration has observed a new state in radiative transitions to \Upsilon(1S) and \Upsilon(2S) and…
Charmonium, the spectroscopy of c\bar{c} mesons, has recently enjoyed a renaissance with the discovery of several missing states and a number of unexpected charmonium-like resonances. The discovery of these new states has been made possible…
Based on 12.0 $\mathrm{fb^{-1}}$ of $e^{+}e^{-}$ collision data samples collected by the BESIII detector at center-of-mass energies from 4.1271 to 4.3583 GeV, a partial wave analysis is performed for the process $e^{+}e^{-} \rightarrow…
The past decade witnessed the observation of several exotic charmonium-like resonances, some of which are manifestly non-qqbar mesons. We review one of the most popular interpretations of such states: the compact tetraquark in the…
In this talk we address two topics: The first one is an empirical explanation in terms of a new state $h_1$ of the peak in the $K^{*0}\bar{K}^{*0}$ invariant mass distribution close to threshold of this channel in the $J/\psi \to \eta…
Recent results in the field of spectroscopy from the BABAR experiment are reported, with particular attention to the new states observed in ISR and $\gamma \gamma$ interactions using the full BABAR data sample. We confirm the states Y(4260)…
Coincidences between charged particles emitted in the $\beta$-decay of $^{11}$Li were observed using highly segmented detectors. The breakup channels involving three particles were studied in full kinematics allowing for the reconstruction…
We perform an effective-field-theory-based coupled-channel analysis of the recent BES III data on the $e^+e^-$ annihilation into the final state $K^+(D_s^-D^{*0}+D_s^{*-}D^0)$ in a wide energy range and extract the poles responsible for the…
The resonance D*_sJ (2317) which is considered to be the 1^3P_0 state composed of charm and strange quarks has been discovered recently. The measured mass, which is about 160 MeV lower than the mass of the 1^3P_0 state obtained from the…
We have studied the loosely bound $D^*\bar{D}^*$ system. Our results indicate that the recently observed charged charmonium-like structure $Z_c(4025)$ can be an ideal $D^*\bar{D}^*$ molecular state. We have also investigated its pionic,…
The recently discovered fully charmed tetraquark candidate $X(6900)$ is analyzed within the frameworks of effective-range expansion, compositeness relation and width saturation, and a coupled multichannel dynamical study. By taking into…
The LHCb Collaboration has recently observed four $J/\psi\phi$ structures called $X(4140)$, $X(4274)$, $X(4500)$ and $X(4700)$ in the $B^{+}\to J/\psi\phi K^{+}$ decays. We study them herein using a nonrelativistic constituent quark model…
We study the mass splittings of $Q_1q_2\bar{Q}_3\bar{q}_4$ ($Q=c,b$, $q=u,d,s$) tetraquark states with chromomagnetic interactions between their quark components. Assuming that $X(4140)$ is the lowest $J^{PC}=1^{++}$ $cs\bar{c}\bar{s}$…
The original charmonium two-body problem, like the $c\bar c$ structure of the $J/\psi$ meson, has become more involved in the last few years with the discovery of new resonances such as the tentative molecular state $X(3872)$ or the…
A review of recent experimental developments concerning the $X$, $Y$ and $Z$ charmonium-like exotic states.
Different from the usual tetraquark assignment to charged $Z_c(3885)$ and $Z_c(4025)$ charmoniumlike structures, in this letter we propose a universal non-resonant explanation to decode these $Z_c$'s, which is based on a special dynamical…
We present a dynamical approach for description of the multi-quark states that is based on an effective interaction Lagrangian describing the coupling of hadrons to their constituent quarks. First, we explore the consequences of treating…
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, $J^{PC}=0^{+(+)}$, $1^{+(\pm)}$,…