5,854 research outputs found
Possible Extension of the Chiral Perturbation Theory Program
After a brief discussion of how chiral dynamics has evolved from the
``universal V-A theory of weak interactions'', we present some evidence that
symmetry breaking for the vector meson multiplet is not simpler than but rather
analogous to that for the pseudoscalar multiplet. This provides a motivation
for speculating on how to extend in a systematic way the chiral perturbation
theory program to include vectors.Comment: Contribution to Marshak Memorial Volume, edited by E.C.G. Sudarshan,
to be published by World Scientific, Singapore 1994, PREPRINT SU-4240-57
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
A potential test of the CP properties and Majorana nature of neutrinos
The scattering of solar neutrinos on electrons may reveal their CP
properties, which are particularly sensitive to their Majorana nature. The
cross section is sensitive to the neutrino dipole moments through an
interference of electro-magnetic and weak amplitudes. We show how future solar
neutrino experiments with good angular resolution and low energy threshold,
such as Hellaz, can be sensitive to the resulting azimuthal asymmetries in
event number, and could therefore provide valuable information on the CP
properties and the nature of the neutrinos, provided the solar magnetic field
direction is fixed.Comment: 14 pages, 1 figure, eq. (19) corrected. Version to be publishe
Study of Scalar Mesons and Related Radiative Decays
After a brief review of the puzzling light scalar meson sector of QCD, a
brief summary will be given of a paper concerning radiative decays involving
the light scalars. There, a simple vector meson dominance model is constructed
in an initial attempt to relate a large number of the radiative decays
involving a putative scalar nonet to each other. As an application it is
illustrated why mixing is not expected to greatly alter the
production ratio for radiative decays.Comment: 9 pages, 3 figures, Talk presented at SUNYIT (Utica/NY) conference on
High Energy Physics, June 6, 200
Correlated random fields in dielectric and spin glasses
Both orientational glasses and dipolar glasses possess an intrinsic random
field, coming from the volume difference between impurity and host ions. We
show this suppresses the glass transition, causing instead a crossover to the
low phase. Moreover the random field is correlated with the inter-impurity
interactions, and has a broad distribution. This leads to a peculiar variant of
the Imry-Ma mechanism, with 'domains' of impurities oriented by a few frozen
pairs. These domains are small: predictions of domain size are given for
specific systems, and their possible experimental verification is outlined. In
magnetic glasses in zero field the glass transition survives, because the
random fields are disallowed by time-reversal symmetry; applying a magnetic
field then generates random fields, and suppresses the spin glass transition.Comment: minor modifications, final versio
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
Anomaly induced QCD potential and Quark Decoupling
We explore the anomaly induced effective QCD meson potential in the framework
of the effective Lagrangian approach. We suggest a decoupling procedure, when a
flavored quark becomes massive, which mimics the one employed by Seiberg for
supersymmetric gauge theories. It is seen that, after decoupling, the QCD
potential naturally converts to the one with one less flavor. We study the
and dependence of the mass.Comment: 11 pages, RevTe
Solar Neutrinos: Status and Prospects
We describe the current status of solar neutrino measurements and of the
theory -- both neutrino physics and solar astrophysics -- employed in
interpreting measurements. Important recent developments include
Super-Kamiokande's determination of the neutrino-electron elastic scattering
rate for 8B neutrinos to 3%; the latest SNO global analysis in which the
inclusion of low-energy data from SNO I and II significantly narrowed the range
of allowed values for the neutrino mixing angle theta12; Borexino results for
both the 7Be and pep neutrino fluxes, the first direct measurements
constraining the rate of ppI and ppII burning in the Sun; global reanalyses of
solar neutrino data that take into account new reactor results on theta13; a
new decadal evaluation of the nuclear physics of the pp chain and CNO cycle
defining best values and uncertainties in the nuclear microphysics input to
solar models; recognition of an emerging discrepancy between two tests of solar
metallicity, helioseismological mappings of the sound speed in the solar
interior, and analyses of the metal photoabsorption lines based on our best
current description of the Sun's photosphere; a new round of standard solar
model calculations optimized to agree either with helioseismology or with the
new photospheric analysis; and, motivated by the solar abundance problem, the
development of nonstandard, accreting solar models, in order to investigate
possible consequences of the metal segregation that occurred in the proto-solar
disk. We review this progress and describe how new experiments such as SNO+
could help us further exploit neutrinos as a unique probe of stellar interiors.Comment: 82 pages, 11 figure
Study of leptonic CP violation
The "complementary" Ansatz, Tr, where is the prediagonal
neutrino mass matrix, seems a plausible approximation for capturing in a
self-contained way some of the content of Grand Unification. We study its
consequences in the form of relations between the neutrino masses and CP
violation phases.Comment: 8 pages, 1 figure, talk at MRST200
The Scalar Sector and the Eta -> 3 Pi Problem
First, recent work on light scalar mesons, which is of possible interest in
connection with the strong coupling region of QCD is briefly discussed. Then a
very short highlighting of a paper concerned with an application to the eta ->
3 pi problem is presented.Comment: 7 pages LaTeX, 4 eps figures, talk at SCGT02 conference at Nagoy
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