Related papers: Quark States Near a Threshold
Assuming the validity of random matrices for describing the statistics of a closed chaotic quantum system, we study analytically some statistical properties of the S-matrix characterizing scattering in its open counterpart. In the first…
The quark-molecular-dynamics model is used to study microscopically the dynamics of the coloured quark phase and the subsequent hadron formation in relativistic S+Au collisions at the CERN-SPS. Particle spectra and hadron ratios are…
The discovery of the $Z_c(3900)^\pm$ and $Z_b(10610)^\pm$ structures in the heavy quarkonium spectrum showed the need to incorporate hadron structures beyond the naive $qqq$ and $q\bar q$ systems in quark models. The new charged structure…
The $s-$wave meson-baryon scattering is analyzed for the isospin-strangeness $I=1/2, S=0$ and $I=0,S=-1$ sectors, in a Bethe-Salpeter coupled channel formalism incorporating Chiral Symmetry. For both sectors, four channels have been…
The structures of N phi states with spin-parity J^{p}=3/2^- and J^p=1/2^- are dynamically studied in both the chiral SU(3) quark model and the extended chiral SU(3) quark model by solving a resonating group method (RGM) equation. The model…
We study the quark mass dependence of the H-dibaryon in the strangeness $S=-2$ baryon-baryon scattering. A low-energy effective field theory is used to describe the coupled-channel scattering, in which the quark mass dependence is…
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 $c\bar c$-$D\bar D{}^*$…
The so far only known charmed non-strange scalar meson is dubbed as $D_0^*(2400)$ in the Review of Particle Physics. We show, within the framework of unitarized chiral perturbation theory, that there are in fact two $(I=1/2, J^P=0^+)$ poles…
We study quasi-bound states and scattering with short range potentials in three dimensions, subject to an axial periodic driving. We find that poles of the scattering S-matrix can cross the real energy axis as a function of the drive…
In this contribution, we discuss the possible importance of continuum-coupling (or threshold) effects in heavy quarkonium spectroscopy. Our calculations are carried out in a coupled-channel model, where meson-meson higher Fock (or…
We report the chiral quark model approach for the study of baryon resonances in meson photoproduction and meson-nucleon scattering processes. Focussing on the $\pi N$ and $K N$ scatterings, we show that the cross sections near threshold can…
Using a nonrelativistic constituent quark model in which the degrees of freedom are quark-antiquark and meson-meson components, we have recently shown that the $D^{(\ast)}K$ thresholds play an important role in lowering the mass of the…
We discuss the general behavior of the scattering amplitude with channel couplings near the two-body threshold. It is known that the Flatt\'{e} amplitude, which is often used in the analysis of experimental data involving exotic hadrons,…
We discuss recent progress concerning the resummation of large logarithms at next-to-leading power (NLP) in scattering processes near threshold. We begin by briefly reviewing the diagrammatic and SCET approach, which are used to derive…
The last two decades are marked by a renaissance in hadronic spectroscopy caused by the arrival of vast experimental information on exotic states in the spectrum of charmonium and bottomonium. Most of such states have properties at odds…
In this work we study the properties of hadronic molecules in the heavy-quark sector. These have become increasingly important since from the beginning of this century a large number of states have been measured that for different reasons…
In a finite volume, resonances and multi-hadron states are identified by discrete energy levels. When comparing the results of lattice QCD calculations to scattering experiments, it is important to have a way of associating the energy…
The $S$-wave $\Lambda K$ and $\Sigma K$ states with isospin $I=1/2$ are dynamically investigated within the framework of the chiral SU(3) quark model by solving a resonating group method (RGM) equation. The model parameters are taken from…
The properties of bound states are fundamental to hadronic spectroscopy and play a central role in the transition from hadronic matter to a quark-gluon plasma (QGP). In a strongly coupled QGP (sQGP), the interplay of temperature, binding…
In this paper we carry out a low-temperature scan of the phase diagram of dense two-color QCD with $N_f=2$ quarks. The study is conducted using lattice simulation with rooted staggered quarks. At small chemical potential we observe the…