scholarly journals Baryon Structure and QCD

1989 ◽  
Vol 42 (2) ◽  
pp. 129 ◽  
Author(s):  
RT Cahill ◽  
CD Roberts ◽  
J Praschifka
Keyword(s):  
Chiral Symmetry ◽  
Baryon Octet ◽  
Gluon Exchange ◽  
Quark Masses ◽  
Colour Singlet ◽  
Zero Current ◽  
Singlet States ◽  
Three Body ◽  
Current Quark

From QCD we derive a three-body Faddeev-type formulation of baryons, as qqq colour-singlet states bound by gluon exchange, which is covariant, has dynamically hidden chiral symmetry and incorporates the colour dynamics. The formulation exploits the dynamical role of colour "3 diquark substructure in baryons to simplify computations. For non-zero current quark masses the jP = ~ + and ~ - baryon octet mass formulae are shown to satisfy the Gell-Mann-Okubo and the Coleman-Glashow multiplet mass relationships.

scholarly journals EFFECTIVE $\bar KN$ INTERACTION AND ROLE OF CHIRAL SYMMETRY

2010 ◽  
Vol 19 (12) ◽  
pp. 2612-2617 ◽  
Author(s):  
Tetsuo Hyodo ◽  
Wolfram Weise
Keyword(s):  
Chiral Symmetry ◽  
Effective Potential ◽  
Single Channel ◽  
Kaonic Nuclei

We study the consequence of chiral SU(3) symmetry in the kaon-nucleon phenomenology, by deriving the effective single-channel [Formula: see text] potential. It turns out that the πΣ interaction is strongly attractive and plays an important role for the structure of the Λ(1405) resonance. We discuss the implication of effective potential for the few-body kaonic nuclei.

ZERO AND FINITE TEMPERATURE STUDY OF SINGLE FULLERENE CAGES AND CARBON “ONIONS” — GEOMETRY AND SHAPE

1993 ◽  
Vol 07 (29n30) ◽  
pp. 1883-1895 ◽  
Author(s):  
A. MAITI ◽  
C.J. BRABEC ◽  
J. BERNHOLC
Keyword(s):  
Interatomic Potential ◽  
Critical Size ◽  
Tight Binding ◽  
Configurational Entropy ◽  
Electronic Structure Calculations ◽  
Carbon Onions ◽  
Three Body ◽  
Structure Calculations ◽  
Scaling Arguments

Scaling arguments are used to show that above a critical size of several thousand atoms, there is a stability crossover from single to multilayer cages. Conjugate gradient minimization using a classical three-body interatomic potential, as well as tight-binding electronic structure calculations yield ground-state configurations for large fullerene shells that are polyhedral with clearly faceted geometry. The structure, energetics and configurational entropy associated with low-energy defects are calculated and the number of defects estimated as a function of temperature. The role of these thermally generated defects on the shape of large fullerenes is investigated in order to explain the nearly spherical shapes of the newly discovered carbon “onions”.

scholarly journals Regge trajectories of exotic hadrons in the flux tube model

2016 ◽  
Vol 31 (04n05) ◽  
pp. 1650007 ◽  
Author(s):  
Hemwati Nandan ◽  
Akhilesh Ranjan
Keyword(s):  
Flux Tube ◽  
Tube Model ◽  
Lattice Data ◽  
High Rotational Speed ◽  
Quark Masses ◽  
Regge Trajectories ◽  
Linear Behavior ◽  
Exotic Hadrons ◽  
Tube Structure ◽  
Current Quark

We have investigated the Regge trajectories of exotic hadrons by considering different possible pentaquark configurations with finite quark mass in the flux tube model. Significant deviation is observed in the linear behavior of the Regge trajectories for pentaquark systems in view of the universal value of the Regge slope parameter for hadrons. The modified Regge trajectories are also compared with the available experimental and lattice data. It is observed that the nonlinear Regge trajectories of such pentaquark systems can be well described by the relativistic corrections in view of the current quark masses and the high rotational speed of the quarks at the end of flux tube structure.

scholarly journals Quark masses and chiral symmetry

1995 ◽  
Vol 52 (5) ◽  
pp. 2951-2959 ◽  
Author(s):  
Michael Creutz
Keyword(s):  
Chiral Symmetry ◽  
Quark Masses

scholarly journals Gastruloids develop the three body axes in the absence of extraembryonic tissues and spatially localised signalling

2017 ◽  
Author(s):  
D.A. Turner ◽  
L. Alonso-Crisostomo ◽  
M. Girgin ◽  
P. Baillie-Johnson ◽  
C. R. Glodowski ◽  
...  
Keyword(s):  
Embryonic Stem ◽  
Model System ◽  
The Body ◽  
Genetic Studies ◽  
Animal Development ◽  
Embryonic Tissues ◽  
Bmp Signalling ◽  
Three Body ◽  
Extraembryonic Tissues

AbstractEstablishment of the three body axes is a critical step during animal development. In mammals, genetic studies have shown that a combination of precisely deployed signals from extraembryonic tissues position the anteroposterior axis (AP) within the embryo and lead to the emergence of the dorsoventral (DV) and left-right (LR) axes. We have used Gastruloids, embryonic organoids, as a model system to understand this process and find that they are able to develop AP, DV and LR axes as well as to undergo axial elongation in a manner that mirror embryos. The Gastruloids can be grown for 160 hours and form derivatives from ectoderm, mesoderm and endoderm. We focus on the AP axis and show that in the Gastruloids this axis is registered in the expression of T/Bra at one pole that corresponds to the tip of the elongation. We find that localisation of T/Bra expression depends on the combined activities of Wnt/β-Catenin and Nodal/Smad2,3 signalling, and that BMP signalling is dispensable for this process. Furthermore, AP axis specification occurs in the absence of both extraembryonic tissues and of localised sources of signalling. Our experiments show that Nodal, together with Wnt/β-Catenin signalling, is essential for the expression of T/Bra but that Wnt signalling has a separable activity in the elongation of the axis. The results lead us to suggest that, in the embryo, the role of the extraembryonic tissues might not be to induce the axes but to bias an intrinsic ability of the embryo to break its initial symmetry and organise its axes.One sentence summaryCulture of aggregates of defined number of Embryonic Stem cells leads to self-organised embryo-like structures which, in the absence of localised signalling from extra embryonic tissues and under the autonomous influence of Wnt and Nodal signalling, develop the three main axes of the body.

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