3,581 research outputs found
Particle Conjugation and the Corrections to
We impose the requirement that the isovector axial vector current for the
soliton sector of the chiral quark model transforms correctly under particle
conjugation. This forces us to choose an otherwise arbitrary ordering of
collective space operators in such a way that the next--to--leading
correction to vanishes.Comment: 6 pages LaTeX, SU--4240--588, UNITU--THEP--23/199
The Skyrme Model for Baryons
We review the Skyrme model approach which treats baryons as solitons of an
effective meson theory. We start out with a historical introduction and a
concise discussion of the original two flavor Skyrme model and its
interpretation. Then we develop the theme, motivated by the large
approximation of QCD, that the {\it effective} Lagrangian of QCD is in fact one
which contains just mesons of all spins. When this Lagrangian is (at least
approximately) determined from the meson sector it should then yield a zero
parameter description of the baryons. We next discuss the concept of chiral
symmetry and the technology involved in handling the three flavor extension of
the model at the collective level. This material is used to discuss properties
of the light baryons based on three flavor meson Lagrangians containing just
pseudoscalars and also pseudoscalars plus vectors. The improvements obtained by
including vectors are exemplified in the treatment of the {\it proton spin
puzzle}.Comment: Invited review for INSA-Book-2000 38 pages, 4 figures included via
epsfi
Three-dimensional nonlinear stability analysis of the sun-perturbed Earth-Moon equilateral points
Nonlinear analytic study of long period features of particle motion in Earth-Moon syste
Analytical study of control devices for high amplitude combustion instability Quarterly report
Mathematical model and analysis of combustion processes in annular rocket engines for control of high amplitude combustion instabilit
Global aspects of the scalar meson puzzle
A generalized linear sigma model for low energy QCD is employed to study the
quark structure of eight low lying scalar isomultiplets as well as eight low
lying pseudoscalar isomultiplets. The model, building on earlier work, assumes
the possible mixing of quark anti-quark states with others made of two quarks
and two antiquarks. No {\it a priori} assumption is made about the quark
contents of the states, which emerge as predictions. An amusing and contrasting
pattern for the quark structure is found; the lighter conventional
pseudoscalars are, as expected, primarily of two quark type whereas the lighter
scalars have very large four quark admixtures. The new feature of the present
paper compared to earlier ones in this series involves the somewhat subtle and
complicated effects of SU(3) flavor breaking. They do not alter the general
pattern of two quark vs. four quark mixing obtained in the SU(3)symmetric case
but, of course, give a more detailed picture
Exploring the structure of a possible light scalar nonet
We first review the work of the Syracuse group, which uses an effective
chiral Lagrangian approach, on meson-meson scattering. An illustration
providing evidence for the existence of a strange scalar resonance of mass
around 900 MeV is given. An attempt to fit this together with a
similarly obtained and the well known and
into a nonet pattern suggests that the underlying structure is closer to a dual
quark-dual antiquark than to a quark-antiquark. A possible mechanism to explain
a next higher-in mass scalar meson nonet is also discussed. This involves
mixing between and states.Comment: 8 pages, 4 figures, invited talk at workshop "Possible Existence of
the Light Sigma Resonance and its Implications to Hadron Physics", Yukawa
Institute for Theoretical Physics, Kyoto, Japan, June 200
Light Scalar Puzzle in QCD
An approach to understanding the light scalar meson phenomenology is briefly
reviewed.Comment: Talk at XII Mexican Workshop on Particles and Fields, 5-14 Nov. 2009,
Mazatlan, Mexic
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