Related papers: XYZ States
Using the pictures for $X(3872)$ as a mixture of charmonium and molecular $D^{\ast 0}D^0$ states; $Y(3940)$ as a mixture of $\chi_{c0}$ and $D^\ast D^{\prime\ast}$ states, and $Y(4260)$ as a mixture of the tetra-quark state with charmonium…
The description of the baryon spectrum is performed using the hypercentral Consituent Quark Model (hCQM), mainly in comparison with the harmonic oscillator (h.o.). Recentlly many new states, at various levels of confidence have been…
We study the nature of the new charm and charmonium like states observed in the last few years, using a constituent quark model with an screened confinement potential. In the open charm sector we discuss different options for the…
The pentaquark state recently discovered has been discussed based on various quark model calculations. Odd parity for the state can not be ruled out theoretically because contributions related to non-trivial color structures have not been…
Great strides have been made in the understanding of bound states of a bottom quark $b$ and its antiquark $\bar b$ since the discovery of the first $\Upsilon$ resonances in 1977. These {\it bottomonium} bound states have a rich spectrum…
Recent issues in heavy flavour physics are reviewed. Anomalies in charmonium, $B$, and $\Upsilon(5S)$ decays and production are highlighted. New results concerning exotic heavy quark states are also briefly reviewed.
Exotic states in the charmonium family are systematically treated in the framework of simplest model with an effective coulomb-like interaction of heavy quark and antiquark in the presence of static excitation of quark-gluon modes…
We review recent studies on exotic states at the Belle experiment. The results include: (1) The measurement of the cross sections of $\gamma \gamma \to \omega \phi$, $\phi\phi$, and $\omega \omega$ for masses that range from threshold to…
Multiquark resonances are undoubtedly experimentally observed. The number of states and the amount of details on their properties has been growing over the years. It is very recent the discovery of two pentaquarks and the confirmation of…
We study the stability of superpositions of macroscopically distinct quantum states under decoherence. We introduce a class of quantum states with entanglement features similar to Greenberger-Horne-Zeilinger (GHZ) states, but with an…
The charmonium spectrum is calculated with two nonrelativistic quark models, the linear potential model and the screened potential model. Using the obtained wavefunctions, we evaluate the electromagnetic transitions of charmonium states up…
Based on the fact that the long expected pentaquark which possesses the exotic quantum numbers of $B=1$ and $S=1$ was not experimentally found, although exotic states of $XYZ$ have been observed recently, we conjecture that the heavy…
Recent lattice QCD results on the hadron spectroscopy with beauty and charm quarks is reviewed. The focus of the review are exotic hadrons, while non-lattice approaches and conventional hadrons are reported as well. We discuss the recently…
We explore in this paper some orthogonal polynomials which are naturally associated to certain families of coherent states, often referred to as nonlinear coherent states in the quantum optics literature. Some examples turn out to be known…
The BESIII Experiment at the Beijing Electron Positron Collider (BEPCII) collected large data samples for electron-positron collisions with center-of-mass above 4 GeV. The analysis of these samples has resulted in a number of surprising…
Nonlinear coherent states are an interesting resource for quantum technologies. Here we investigate some critical features of the single-boson nonlinear coherent states, which are theoretically constructed as eigenstates of the annihilation…
We study the spectroscopy of the states which defy conventional $c\bar{c}$ charmonium and $b\bar{b}$ bottomonium interpretation respectively, and are termed as exotic states. In August 2003 a state X(3872), was discovered [K. Abe\textit{\…
We study the charmonium properties at finite temperature using quenched lattice QCD simulations. Although a simple potential model analysis indicates no bound state at $T>1.05T_c$, our analyses of the spatial correlation between quark and…
Despite the apparent simplicity of meson spectroscopy there are some states which cannot be accommodated in the usual $q\bar q$ structure. Among them there are either exotic states as the X(1600) or the recently measured charm states…
We study the possible charmonium-like states with $J^{PC}=0^{--}, 0^{-+}$ using the tetraquark interpolating currents with the QCD sum rules approach. The extracted masses are around 4.5 GeV for the $0^{--}$ charmonium-like states and 4.6…