Related papers: Special Issue on Advances in Chiral Quark Models
The observation of many unexpected states decaying into heavy quarkonia has challenged the usual QQbar interpretation. One of the most studied exotic states, the X(3872), happens to be copiously produced in high-energy hadron collisions. We…
Recent developments and open issues in chiral dynamics with strange quarks are reviewed. Topics include: Order parameters of chiral symmetry breaking, the flavor dependence of these order parameters, speculations about the phase structure…
Hadrons, composed of quarks and gluons bound by Quantum Chromodynamics (QCD), traditionally classified as baryons (three quarks) and mesons (quark-antiquark pairs). Nothing in the theory of QCD stands against the existence of exotic hadrons…
The nature of the $X(3872)$ and other exotic hadrons has been a subject of extensive investigation since the first observation of the $X(3872)$ in 2003. While various theoretical models have been proposed, including hadronic molecular and…
The structure of exotic resonances that do not trivially fit the usual quark model expectations has been a matter of intense scientific debate during the last two decades. A possible way of estimating the size of these states is to study…
We investigate the core dynamics behind exotic matter formation via the TQ4Q1.1 set of collinear fragmentation functions for fully charmed or bottomed tetraquarks in three quantum configurations: scalar ($0^{++}$), axial vector ($1^{+-}$),…
In the quark model, hadrons are dominantly bound states of quark-antiquark pairs (mesons) or three quarks (baryons), but QCD also allows hadronic states to be composed of more quarks bound together. Recently, BESIII, Belle and LHCb have…
We discuss recent progress made studies of bulk thermodynamics of strongly interacting matter through lattice simulations of QCD with an almost physical light and strange quark mass spectrum. We present results on the QCD equation of state…
After the discovery of the Quantum Chromodynamics (QCD), many experimental and theoretical efforts have been made to investigate physics issues involved in ultra relativistic heavy-ion collisions. The fundamental goal of this work is to…
The past fifty years have seen the emergence of a new field of research in physics, the study of matter at extreme temperatures and densities. The theory of strong interactions, quantum chromodynamics (QCD), predicts that in this limit,…
We construct an effective model for the QCD equation of state, taking into account chiral symmetry restoration as well as the deconfinement phase transition. The correct asymptotic degrees of freedom at the high and low temperature limits…
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 explain a method to find internal quark configurations of exotic hadron candidates by using the constituent counting rule. The counting rule was theoretically predicted in perturbative QCD for hard exclusive hadron reactions, and it has…
Searching for exotic multiquark states and elucidating their nature remains a central topic in understanding quantum chromodynamics--the underlying theory of the strong interaction. Two of the most studied such states are the charm-strange…
I give a brief outline of the theoretical framework for the modern treatment of the strong interaction effects in heavy quark decays, based on first principles of QCD. This model-independent approach is required to meet the precision of…
I review recent lattice QCD results on a few selected topics which are relevant to the heavy ion physics community. Special emphasis is put on the QCD equation of state at vanishing and nonzero baryon chemical potential, the onset of…
This short paper is an attempt to describe a theorist's view of the goals of relativistic heavy ion program which has just entered the collider era. These goals are centered around understanding the properties and the critical behavior of…
I give a summary of Section E of the sixth edition of the Conference "Quark confinement and the hadron spectrum". Papers were presented on different subjects, from spectroscopy, including pentaquarks and hadron structure, to new physics…
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 discuss exotic states X(3872) and $Z^+(4430)$, observed recently in experiment Belle. The QCD-string based explanation is suggested.