The intriguing experiment of Geiger and Marsden in collaboration with Rutherford, in which they scattered alpha particles from gold foils to find the existence of the tiny nucleus, was the beginning of a new era of discoveries on the strong interaction in Physics. Radioactivity and its role in medical physics, the nuclear fission, the role of nuclear fusion in cooking elements in stars, the discovery of the hadrons, which behaved in unexpected ways and forced the introduction of new quantum numbers, and the existence of quark gluon plasma brought forth many aspects of strong interaction physics. After more than a hundred years of theoretical and experimental investigations, there seemed to have developed consensus on our understanding of nuclear and hadron physics. Any new phenomenon that went beyond the standard explanations in this field got named exotic.
Surprisingly enough, proposals and discoveries of exotic aspects of hadrons and nuclei in the past two decades have not been few. Radioactive beam facilities have opened new horizons to reveal new information on nuclear structure, measure cross sections of crucial importance for nucleosynthesis and possible future medical applications with particle therapy. Dramatic deviations from the matter distribution of ordinary stable nuclei were observed in the so-called halo nuclei with the Tango and Borromean being some of the interesting configurations. In the case of hadron physics, the discovery of X(3872) marked a turning point. Since then, several exotic hadrons have been discovered, with the latest one being the doubly charmed Tcc. Such findings are completely unprecedented and have generated an intense debate on the properties of exotic hadrons and on the implications of their existence. They could be categorized as compact multiquark states such as the pentaquarks and tetraquarks or weakly bound hadron molecules that are composed of two or more conventional hadrons. The existence of glueballs or hybrid states of quarks and gluons is not excluded. The aim of this issue is to bring forth the new face of nuclear and hadron physics in the twenty-first century.
The above includes the formation of exotic states of nuclear matter and decays as well as exotic aspects of their interaction and role in reactions of astrophysical interest. To shed light on unresolved issues and promote further experimental exploration, we invite authors to present Mini Reviews, as well as Original Research, on the new theoretical or experimental findings on:
1. Few body aspects of Borromean and other halo nuclei
2. Hyperon-nucleon interaction and the role of hypernuclei in neutron stars
3. Neutron and proton drip line physics
4. Exotic bound states of mesons such as the eta, pi, K, D0 and nuclei
5. Pentaquarks, tetraquarks, dibaryon sextaquarks, glueballs and hybrid states of quarks and gluons
6. Manifestation and nature of diproton and dineutron emission
7. Exotic hadrons states beyond the naive quark model
8. Exotic decay modes of medium, heavy and superheavy nuclei
9. Two- and multi-body hadronic molecules
10. Three-body resonances.
Other relevant topics are welcomed at the suggestion of the authors.
The intriguing experiment of Geiger and Marsden in collaboration with Rutherford, in which they scattered alpha particles from gold foils to find the existence of the tiny nucleus, was the beginning of a new era of discoveries on the strong interaction in Physics. Radioactivity and its role in medical physics, the nuclear fission, the role of nuclear fusion in cooking elements in stars, the discovery of the hadrons, which behaved in unexpected ways and forced the introduction of new quantum numbers, and the existence of quark gluon plasma brought forth many aspects of strong interaction physics. After more than a hundred years of theoretical and experimental investigations, there seemed to have developed consensus on our understanding of nuclear and hadron physics. Any new phenomenon that went beyond the standard explanations in this field got named exotic.
Surprisingly enough, proposals and discoveries of exotic aspects of hadrons and nuclei in the past two decades have not been few. Radioactive beam facilities have opened new horizons to reveal new information on nuclear structure, measure cross sections of crucial importance for nucleosynthesis and possible future medical applications with particle therapy. Dramatic deviations from the matter distribution of ordinary stable nuclei were observed in the so-called halo nuclei with the Tango and Borromean being some of the interesting configurations. In the case of hadron physics, the discovery of X(3872) marked a turning point. Since then, several exotic hadrons have been discovered, with the latest one being the doubly charmed Tcc. Such findings are completely unprecedented and have generated an intense debate on the properties of exotic hadrons and on the implications of their existence. They could be categorized as compact multiquark states such as the pentaquarks and tetraquarks or weakly bound hadron molecules that are composed of two or more conventional hadrons. The existence of glueballs or hybrid states of quarks and gluons is not excluded. The aim of this issue is to bring forth the new face of nuclear and hadron physics in the twenty-first century.
The above includes the formation of exotic states of nuclear matter and decays as well as exotic aspects of their interaction and role in reactions of astrophysical interest. To shed light on unresolved issues and promote further experimental exploration, we invite authors to present Mini Reviews, as well as Original Research, on the new theoretical or experimental findings on:
1. Few body aspects of Borromean and other halo nuclei
2. Hyperon-nucleon interaction and the role of hypernuclei in neutron stars
3. Neutron and proton drip line physics
4. Exotic bound states of mesons such as the eta, pi, K, D0 and nuclei
5. Pentaquarks, tetraquarks, dibaryon sextaquarks, glueballs and hybrid states of quarks and gluons
6. Manifestation and nature of diproton and dineutron emission
7. Exotic hadrons states beyond the naive quark model
8. Exotic decay modes of medium, heavy and superheavy nuclei
9. Two- and multi-body hadronic molecules
10. Three-body resonances.
Other relevant topics are welcomed at the suggestion of the authors.
