402 research outputs found
Operator Manifold Approach to Geometry and Particle Physics
The question that guides our discussion is how did the geometry and particles
come into being. The present theory reveals primordial deeper structures
underlying fundamental concepts of contemporary physics. We begin with a
drastic revision of a role of local internal symmetries in physical concept of
curved geometry. A standard gauge principle of local internal symmetries is
generalized. The gravitation gauge group is proposed, which is generated by
hidden local internal symmetries. Last two parts address to the question of
physical origin of geometry and basic concepts of particle physics such as the
fields of quarks with the spins and various quantum numbers, internal
symmetries and so forth; also four basic principles of Relativity, Quantum,
Gauge and Color Confinement, which are, as it was proven, all derivative and
come into being simultaneously. The most promising aspect of our approach so
far is the fact that many of the important anticipated properties, basic
concepts and principles of particle physics are appeared quite naturally in the
framework of suggested theory.Comment: LaTex, 42 pages, email [email protected]
Chiral and Gluon Condensates at Finite Temperature
We investigate the thermal behaviour of gluon and chiral condensates within
an effective Lagrangian of pseudoscalar mesons coupled to a scalar glueball.
This Lagrangian mimics the scale and chiral symmetries of QCD. (Submitted to Z.
Phys. C)Comment: 20 pages + 7 figures (uuencoded compressed postscript files),
University of Regensburg preprint TPR-94-1
Coherent information analysis of quantum channels in simple quantum systems
The coherent information concept is used to analyze a variety of simple
quantum systems. Coherent information was calculated for the information decay
in a two-level atom in the presence of an external resonant field, for the
information exchange between two coupled two-level atoms, and for the
information transfer from a two-level atom to another atom and to a photon
field. The coherent information is shown to be equal to zero for all
full-measurement procedures, but it completely retains its original value for
quantum duplication. Transmission of information from one open subsystem to
another one in the entire closed system is analyzed to learn quantum
information about the forbidden atomic transition via a dipole active
transition of the same atom. It is argued that coherent information can be used
effectively to quantify the information channels in physical systems where
quantum coherence plays an important role.Comment: 24 pages, 7 figs; Final versiob after minor changes, title changed;
to be published in Phys. Rev. A, September 200
Heavy-Higgs Lifetime at Two Loops
The Standard-Model Higgs boson with mass decays almost
exclusively to pairs of and bosons. We calculate the dominant two-loop
corrections of to the partial widths of these decays. In
the on-mass-shell renormalization scheme, the correction factor is found to be
, where the second term is the
one-loop correction. We give full analytic results for all divergent two-loop
Feynman diagrams. A subset of finite two-loop vertex diagrams is computed to
high precision using numerical techniques. We find agreement with a previous
numerical analysis. The above correction factor is also in line with a recent
lattice calculation.Comment: 26 pages, 6 postscript figures. The complete paper including figures
is also available via WWW at
http://www.physik.tu-muenchen.de/tumphy/d/T30d/PAPERS/TUM-HEP-247-96.ps.g
Axion and neutrino physics from anomaly cancellation
It has been recently shown that the requirement of anomaly cancellation in a
(non-supersymmetric) six-dimensional version of the standard model fixes the
field content to the known three generations. We discuss the phenomenological
consequences of the cancellation of the local anomalies: the strong CP problem
is solved and the fundamental scale of the theory is bounded by the physics of
the axion. Neutrinos acquire a mass in the range suggested by atmospheric
experiments.Comment: 9 pages, RevTeX
Estimate of the Collins fragmentation function in a chiral invariant approach
We predict the features of the Collins function, which describes the
fragmentation of a transversely polarized quark into an unpolarized hadron, by
modeling the fragmentation process at a low energy scale. We use the chiral
invariant approach of Manohar and Georgi, where constituent quarks and
Goldstone bosons are considered as effective degrees of freedom in the
non-perturbative regime of QCD. To test the approach we calculate the
unpolarized fragmentation function and the transverse momentum distribution of
a produced hadron, both of which are described reasonably well. In the case of
semi-inclusive deep-inelastic scattering, our estimate of the Collins function
in connection with the transversity distribution gives rise to a transverse
single spin asymmetry of the order of 10%, supporting the idea of measuring the
transversity distribution of the nucleon in this way. In the case of e+ e-
annihilation into two hadrons, our model predicts a Collins azimuthal asymmetry
of about 5%.Comment: 12 pages, 15 figures. Figs. 11-14 changed, minor changes in
discussion, few typos fixed and some references added. Final version to
appear in PR
High-Tc via electron polar coupling: relation to low-Tc superconductivity and to chiral symmetry in particle physics
Directional coupling of Thornber-Feynman polarization with the high-Tc ARPES
distribution specifies the optimum flatband pseudogap \Delta and mobile
localized quasiparticle. This coupling peaks by tuning the statistics and
interaction energy to produce stable short-ranged directional pairing that
reflects the lattice asymmetry. Analogous energy gap and BCS ratio parameters
are identified for low-Tc long-range acoustical phonons and for
quark-anti-quark tightly bound chiral pions in particle physics.Comment: 25 pages, 4 figures, accepted for publication in Physica
Natural Theories of Ultra-Low Mass PNGB's: Axions and Quintessence
We consider the Wilson Line PNGB which arises in a U(1)^N gauge theory,
abstracted from a latticized, periodically compactified extra dimension U(1).
Planck scale breaking of the PNGB's global symmetry is suppressed, providing
natural candidates for the axion and quintessence. We construct an explicit
model in which the axion may be viewed as the 5th component of the U(1)_Y gauge
field in a 1+4 latticized periodically compactified extra dimension. We also
construct a quintessence PNGB model where the ultra-low mass arises from
Planck-scale suppressed physics itself.Comment: 20 pages, fixed typo and reference
Quinstant Dark Energy Predictions for Structure Formation
We explore the predictions of a class of dark energy models, quinstant dark
energy, concerning the structure formation in the Universe, both in the linear
and non-linear regimes. Quinstant dark energy is considered to be formed by
quintessence and a negative cosmological constant. We conclude that these
models give good predictions for structure formation in the linear regime, but
fail to do so in the non-linear one, for redshifts larger than one.Comment: 9 pages, 14 figures, "Accepted for publication in Astrophysics &
Space Science
Novel Approach to Confront Electroweak Data and Theory
A novel approach to study electroweak physics at one-loop level in generic
theories is introduced. It separates the 1-loop
corrections into two pieces: process specific ones from vertex and box
contributions, and universal ones from contributions to the gauge boson
propagators. The latter are parametrized in terms of four effective form
factors , , and corresponding to the , , and
propagators. Under the assumption that only the Standard Model contributes to
the process specific corrections, the magnitudes of the four form factors are
determined at and at q^2=\mmz by fitting to all available precision
experiments. These values are then compared systematically with predictions of
theories. In all fits \alpha_s(\mz) and
\bar{\alpha}(\mmz) are treated as external parameters in order to keep the
interpretation as flexible as possible. The treatment of the electroweak data
is presented in detail together with the relevant theoretical formulae used to
interpret the data. No deviation from the Standard Model has been identified.
Ranges of the top quark and Higgs boson masses are derived as functions of
\alpha_s(\mz) and \bar{\alpha}(\mmz). Also discussed are consequences of
the recent precision measurement of the left-right asymmetry at SLC as well as
the impact of a top quark mass and an improved mass measurement.Comment: 123 pages, LaTeX (33 figures available via anonymous ftp),
KEK-TH-375, KEK preprint 93-159, KANAZAWA-94-19, DESY 94-002, YUMS 94-22,
SNUTP 94-82, to be published in Z.Phys.
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