MASSIVE-QUARK BARYONS AS SKYRMIONS

1991 ◽  
Vol 06 (23) ◽  
pp. 2087-2100 ◽  
Author(s):  
MANNQUE RHO
Keyword(s):  
Degrees Of Freedom ◽  
Pivotal Role ◽  
Massive Scalar ◽  
Massive Quark ◽  
B Quarks ◽  
Quark Models

Massive-quark baryons containing one or more charm (c) or bottom (b) quarks are described as massive scalar doublet fields "wrapped" by the soliton of the light (up and down) flavors. The spin-isospin transmutation that takes place to make the trapped scalar behave like heavy-flavored quarks is analogous to what happens to a scalar doublet in the presence of a 't Hooft–Polyakov monopole. The Wess–Zumino term plays a pivotal role here. This model predicts spectra that resemble closely those of quark models. This feature is interpreted in terms of an induced gauge (or Berry) structure associated with "fast" and "slow" degrees of freedom corresponding, respectively, to the massive- and light-flavor quarks involved in the baryon structure.

MESON-DIQUARK LOOP EXPANSION

1993 ◽  
Vol 08 (02) ◽  
pp. 277-300 ◽  
Author(s):  
M. LUTZ ◽  
J. PRASCHIFKA
Keyword(s):  
Field Theory ◽  
Quantum Field Theory ◽  
Effective Action ◽  
Degrees Of Freedom ◽  
Auxiliary Field ◽  
Quantum Field ◽  
Field Approach ◽  
Loop Expansion ◽  
Quark Models

We consider a general (nonlocal) four-fermion quantum field theory and show how the Cornwall-Jackiw-Tomboulis effective action can be systematically expanded in the number, η, of composite, bose loops. This is achieved by the introduction of auxiliary, bilocal fields which describe fermion-fermion and fermion-antifermion correlations. The η expansion can be understood as a generalization of the [Formula: see text] expansion and is of particular interest in quark models, for example, where the bilocal fields can be identified with meson and diquark degrees of freedom. Comparison with the usual loop (ħ) expansion reveals some unusual characteristics of the η expansion and throws light on recent studies of diquark degrees of freedom in which the auxiliary field approach is used.

MESON SPECTROSCOPY AT JLAB AT 12 GEV

2014 ◽  
Vol 35 ◽  
pp. 1460411
Author(s):  
STUART FEGAN
Keyword(s):  
Electron Beam ◽  
Nuclear Physics ◽  
Degrees Of Freedom ◽  
Real Photon ◽  
Photon Beams ◽  
Accelerator Facility ◽  
Exotic States ◽  
Meson Spectroscopy ◽  
Quark Models ◽  
New Generation

The 12 GeV upgrade to the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab will enable a new generation of experiments in hadronic nuclear physics, seeking to address fundamental questions in our understanding of QCD. The existence of exotic states, suggested by both quark models and lattice calculations, would allow gluonic degrees of freedom to be explored, and may help explain the role played by gluons in the QCD interaction. This article will review the meson spectroscopy program being planned at the lab following the 12 GeV upgrade, utilising real and quasi-real photon beams in two of the lab's four experimental halls, whose distinct capabilities will enable an extensive set of spectroscopy experiments to be performed at the same facility.

IN-MEDIUM NEUTRON-PROTON MASS DIFFERENCE WITH NUCLEAR CHIRAL MODELS

1992 ◽  
Vol 01 (04) ◽  
pp. 871-882 ◽  
Author(s):  
G. KREIN ◽  
D. P. MENEZES ◽  
M. NIELSEN
Keyword(s):  
Nuclear Matter ◽  
Degrees Of Freedom ◽  
Sum Rules ◽  
Mass Difference ◽  
Coupling Constants ◽  
Charge Symmetry Breaking ◽  
Charge Symmetry ◽  
Hartree Fock ◽  
Proton Mass ◽  
Quark Models

The neutron-proton mass difference in nuclear matter is calculated within the context of chiral models involving nucleon and meson degrees of freedom. The interplay of chiral symmetry and charge symmetry breaking on neutron and proton self-energies are discussed in a relativistic Hartree–Fock approximation. Exchange terms are crucial to obtain different contributions for the neutron and proton self-energies. Density dependence of meson masses and coupling constants are taken into account. We find that the neutron-proton mass difference in nuclear matter increases as the density increases, contrary to the predictions of several quark models and of QCD sum rules at finite density.

The motion of a lunar orbiter

1966 ◽  
Vol 25 ◽  
pp. 373
Author(s):  
Y. Kozai
Keyword(s):  
Degrees Of Freedom ◽  
Dimensional Space ◽  
Artificial Satellite ◽  
Equations Of Motion ◽  
Triaxial Ellipsoid ◽  
The Moon ◽  
Secular Motion ◽  
The Earth ◽  
Close Satellite ◽  
The Mean

The motion of an artificial satellite around the Moon is much more complicated than that around the Earth, since the shape of the Moon is a triaxial ellipsoid and the effect of the Earth on the motion is very important even for a very close satellite.The differential equations of motion of the satellite are written in canonical form of three degrees of freedom with time depending Hamiltonian. By eliminating short-periodic terms depending on the mean longitude of the satellite and by assuming that the Earth is moving on the lunar equator, however, the equations are reduced to those of two degrees of freedom with an energy integral.Since the mean motion of the Earth around the Moon is more rapid than the secular motion of the argument of pericentre of the satellite by a factor of one order, the terms depending on the longitude of the Earth can be eliminated, and the degree of freedom is reduced to one.Then the motion can be discussed by drawing equi-energy curves in two-dimensional space. According to these figures satellites with high inclination have large possibilities of falling down to the lunar surface even if the initial eccentricities are very small.The principal properties of the motion are not changed even if plausible values ofJ3andJ4of the Moon are included.This paper has been published in Publ. astr. Soc.Japan15, 301, 1963.

Representing utility and deploying the body

2020 ◽  
Vol 43 ◽  
Author(s):  
David Spurrett
Keyword(s):  
Functional Activity ◽  
Degrees Of Freedom ◽  
The Body ◽  
Target Article ◽  
Processing Demands ◽  
The Many

Abstract Comprehensive accounts of resource-rational attempts to maximise utility shouldn't ignore the demands of constructing utility representations. This can be onerous when, as in humans, there are many rewarding modalities. Another thing best not ignored is the processing demands of making functional activity out of the many degrees of freedom of a body. The target article is almost silent on both.

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