Related papers: Dynamics of Multiquark Systems: Mass, Width and Ex…
In the first part I briefly survey recent issues in constituent quark models raised by the observation of unusual hadronic states. In particular I discuss the role of higher Fock components in the wave function of baryons and the possible…
Progress in determining the spectrum of excited baryons and mesons in lattice QCD is described. Large sets of carefully-designed hadron operators have been studied and their effectiveness in facilitating the extraction of excited-state…
The molecular picture and the constituent-quark model of exotic hadrons are reviewed, with application to the states recently discovered in the hidden-charm and hidden beauty sectors, and to other configurations.
We propose a new approach in QCD sum rules applied for exotic hadrons with a number of quarks, exemplifying the pentaquark Theta^{+} (I=0,J=1/2) in the Borel sum rule. Our approach enables reliable extraction of the pentaquark properties…
The study of exotic multi-quark states has garnered significant attention recently, particularly in heavy-quark dynamics within quantum chromodynamics (QCD). We perform a comprehensive spectroscopic analysis of fully heavy pentaquark states…
The first evidence for Quantum Chromodynamics (QCD), the theory of the strong interactions, came from the systematics of baryon and meson spectroscopy. An important early observation was the apparent absence of exotics, baryons requiring…
We review selected lattice results on the charmonium spectrum and first attempts to search for the existence of exotic states. The hadro-quarkonium model was proposed to interpret some of the exotic states as a quarkonium core inside a…
We discuss the status of current dynamical lattice QCD simulations in connection to the emerging results on the strange and charmed baryon spectrum, excited states of the nucleon and the investigation of the structure of scalar mesons.
Recent experimental evidence for the Theta^+(1540) has given rise to much theoretical interest in exotic baryons. The Theta^+ is a baryon that has strangeness S=+1, meaning that it contains an anti-strange quark. Thus it cannot be…
Exotic hadron states beyond the conventional $qqq$ baryon and $q\bar{q}$ meson configurations are well expected from QCD. Having been successful in the past decades, the heavy quarkonium sector is proved to be an ideal place for the study…
In the framework of the color-magnetic interaction, we systematically investigate the mass splittings of the $QQ\bar{Q}\bar{q}$ tetraquark states and estimated their rough masses in this work. These systems include the explicitly exotic…
The employment of interpolating currents of existed studies of four-quark state and glueball with QCD sum rule approach is analyzed. In terms of suitable currents, the masses of the lowest lying scalar and pseudo-scalar glueball were…
A review is given to pentaquark mass predictions in quark models and QCD. It is pointed out that no successful quark model prediction is available for low-lying pentaquark states. Some new results of direct application of QCD, QCD sum rules…
According to QCD, there exists a broken dynamical supersymmetry between an antiquark and a diquark. This supersymmetry can be used to relate the mass of a pentaquark to the mass of an antibaryon by replacing two antiquarks in an antibaryon…
We study pentaquark $\Theta^{+} (I=0,J=1/2)$ in the QCD sum rules emphasizing that we can not extract any properties of the pentaquark outside of the Borel window. To find the appropriate Borel window, we prepare a favorable set up of the…
More and more hadron states are found to be difficult to be accommodated by the quenched quark models which describe baryons as 3-quark states and mesons as antiquark-quark states. Dragging out an antiquark-quark pair from the gluon field…
A new mechanism of the production of hypothetical $\Theta(ud\bar{s}ud)^+$ pentaquark state is suggested. The considered mechanism is based on the exchange by exotic Regge trajectories in the $t$ channel. It is shown that the momentum…
The precision reached by recent lattice QCD results allows for the first time to investigate whether the measured hadronic spectrum is missing some additional strange states, which are predicted by the Quark Model but have not yet been…
We search for possibly existent bound states in the heavy-light tetraquark channels with quark content $ \bar{b}\bar{b}ud $, $ \bar{b}\bar{b}us $ and $ \bar{b}\bar{c}ud $ using lattice QCD. We carry out calculations on several gauge link…
Inspired by the observed $X(2900)$, we study systematically the mass spectra of the ground pentaquark states with the $qqqq\bar{Q}$ ($Q=c,b$; $q=n,s$; $n=u,d$) configuration in the framework of the Chromomagnetic Interaction model. We…