scholarly journals Symmetries in subatomic multi-quark systems

2018 ◽  
Vol 27 (12) ◽  
pp. 1840003
Author(s):  
J. D. Vergados ◽  
D. Strottman
Keyword(s):  
Quantum Chromodynamics ◽  
Quark Model ◽  
Spin Symmetry ◽  
Wave Functions ◽  
Low Energy ◽  
Isospin Symmetry ◽  
Permutation Symmetry

We discus the role of Quantum Chromodynamics (QCD) in low energy phenomena involving the color-spin symmetry of the quark model. We then combine it with orbital and isospin symmetry to obtain wave functions with the proper permutation symmetry, focusing on multi-quark systems.

EFFECTIVE DEGREES OF FREEDOM IN LOW-ENERGY QUANTUM CHROMODYNAMICS

2013 ◽  
Vol 28 (26) ◽  
pp. 1360022 ◽  
Author(s):  
WILLIBALD PLESSAS
Keyword(s):  
Quantum Mechanics ◽  
Quantum Chromodynamics ◽  
Quark Model ◽  
Chiral Symmetry ◽  
Degrees Of Freedom ◽  
Constituent Quark ◽  
Mass Operator ◽  
Constituent Quark Model ◽  
Low Energy ◽  
Energy Quantum

Confinement and spontaneous breaking of chiral symmetry are assumed to generate the governing degrees of freedom of low-energy quantum chromodynamics. On this basis a relativistic constituent-quark model is constructed and formulated along an invariant mass operator within Poincaré-invariant quantum mechanics. The model is effectively applied to the spectroscopy of all known baryons of flavors u, d, s, c and b. The mass-operator eigenstates are furthermore tested with regard to the baryon electromagnetic and axial form factors. Through using the point form of relativistic quantum mechanics, these observables are obtained in a manifestly covariant manner. For all light and strange baryon ground states the electroweak structures are reproduced either in good agreement with phenomenology or, if no experimental data exist, in consistency with results available from lattice quantum chromodynamics. It is concluded that the relativistic constituent-quark model, relying on {QQQ} Fock states only, provides a universal framework for the description of low-energy baryons. The most important ingredients are spontaneous chiral-symmetry breaking and strict relativistic invariance.

The constituent-quark model — Nowadays

2015 ◽  
Vol 30 (02) ◽  
pp. 1530013 ◽  
Author(s):  
W. Plessas
Keyword(s):  
Quantum Chromodynamics ◽  
Quark Model ◽  
Constituent Quark ◽  
Goldstone Boson ◽  
Form Factors ◽  
Constituent Quark Model ◽  
Low Energy ◽  
Universal Model ◽  
Boson Exchange ◽  
Good Agreement

The present performance of the constituent-quark model as an effective tool to describe low-energy hadrons on the basis of quantum chromodynamics is exemplified along the relativistic constituent-quark model with quark dynamics relying on a realistic confinement and a Goldstone-boson-exchange hyperfine interaction. In particular, the spectroscopy of all known baryons is covered within a universal model in good agreement with phenomenology. The structure of the nucleons as probed under electromagnetic, weak, and gravitational interactions is produced in a correct manner. Likewise, the electroweak form factors of the baryons with u, d, and s flavor contents, calculated so far, result reasonably. Shortcomings still remain with regard to hadronic resonance decays.

DIRAC EQUATION FOR A COULOMB SCALAR, VECTOR AND TENSOR INTERACTION

2011 ◽  
Vol 26 (06) ◽  
pp. 1011-1018 ◽  
Author(s):  
S. ZARRINKAMAR ◽  
H. HASSANABADI ◽  
A. A. RAJABI
Keyword(s):  
Quantum Mechanics ◽  
Dirac Equation ◽  
Exact Solutions ◽  
Pseudospin Symmetry ◽  
Spin Symmetry ◽  
Tensor Interaction ◽  
Wave Functions ◽  
Energy Eigenvalues ◽  
Coulomb Term

There is now motivating experimental evidence for relativistic symmetries in nuclei and hadrons, namely pseudospin and spin symmetry limits of the Dirac equation besides the old theoretical backgrounds. The most fundamental ingredients in such studies are definitely the wave functions and energy eigenvalues. Here, having in mind the importance of the Coulomb term as well as the degeneracy-removing role of tensor interaction, we obtain the exact solutions to the problem for Coulomb scalar, vector and tensor terms in both spin and pseudospin symmetry limits. We see that, contrary to many other common cumbersome techniques, the problem is simply solved via the methodology of supersymmetric quantum mechanics.

scholarly journals Exploiting Isospin Symmetry to Study the Role of Isomers in Stellar Environments

2021 ◽  
Vol 126 (4) ◽  
Author(s):  
S. Hallam ◽  
G. Lotay ◽  
A. Gade ◽  
D. T. Doherty ◽  
J. Belarge ◽  
...  
Keyword(s):  
Isospin Symmetry

scholarly journals Influence of TOPO and TOPO-CdSe/ZnS Quantum Dots on Luminescence Photodynamics of InP/InAsP/InPHeterostructure Nanowires

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 640
Author(s):  
Artem I. Khrebtov ◽  
Vladimir V. Danilov ◽  
Anastasia S. Kulagina ◽  
Rodion R. Reznik ◽  
Ivan D. Skurlov ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Excited States ◽  
Molecular Beam ◽  
Surface Passivation ◽  
Low Energy ◽  
Trioctylphosphine Oxide ◽  
Reverse Transfer ◽  
Semiconductor Heterostructure ◽  
Ligand Type

The passivation influence by ligands coverage with trioctylphosphine oxide (TOPO) and TOPO including colloidal CdSe/ZnS quantum dots (QDs) on optical properties of the semiconductor heterostructure, namely an array of InP nanowires (NWs) with InAsP nanoinsertion grown by Au-assisted molecular beam epitaxy on Si (111) substrates, was investigated. A significant dependence of the photoluminescence (PL) dynamics of the InAsP insertions on the ligand type was shown, which was associated with the changes in the excitation translation channels in the heterostructure. This change was caused by a different interaction of the ligand shells with the surface of InP NWs, which led to the formation of different interfacial low-energy states at the NW-ligand boundary, such as surface-localized antibonding orbitals and hybridized states that were energetically close to the radiating state and participate in the transfer of excitation. It was shown that the quenching of excited states associated with the capture of excitation to interfacial low-energy traps was compensated by the increasing role of the “reverse transfer” mechanism. As a result, the effectiveness of TOPO-CdSe/ZnS QDs as a novel surface passivation coating was demonstrated.

scholarly journals Temperature-Induced Plasmon Excitations for the α–T3 Lattice in Perpendicular Magnetic Field

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1720
Author(s):  
Antonios Balassis ◽  
Godfrey Gumbs ◽  
Oleksiy Roslyak
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Zeeman Splitting ◽  
Mass Term ◽  
Energy Dispersive Spectrum ◽  
Wave Functions ◽  
Transition Energies ◽  
Gap Opening ◽  
Quantizing Magnetic Field

We have investigated the α–T3 model in the presence of a mass term which opens a gap in the energy dispersive spectrum, as well as under a uniform perpendicular quantizing magnetic field. The gap opening mass term plays the role of Zeeman splitting at low magnetic fields for this pseudospin-1 system, and, as a consequence, we are able to compare physical properties of the the α–T3 model at low and high magnetic fields. Specifically, we explore the magnetoplasmon dispersion relation in these two extreme limits. Central to the calculation of these collective modes is the dielectric function which is determined by the polarizability of the system. This latter function is generated by transition energies between subband states, as well as the overlap of their wave functions.

The role of an energy-dependent inner potential in quantitative low-energy electron diffraction

2000 ◽  
Vol 458 (1-3) ◽  
pp. 155-161 ◽  
Author(s):  
S Walter ◽  
V Blum ◽  
L Hammer ◽  
S Müller ◽  
K Heinz ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Low Energy ◽  
Energy Electron ◽  
Low Energy Electron Diffraction ◽  
Low Energy Electron ◽  
Energy Dependent
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