493,658 research outputs found
Multidimensional Dynamical Systems Accepting the Normal Shift
The dynamical systems of the form \ddot\bold r=\bold F (\bold r,\dot\bold
r) in accepting the normal shift are considered. The concept of
weak normality for them is introduced. The partial differential equations for
the force field \bold F(\bold r,\dot\bold r) of the dynamical systems with
weak and complete normality are derived.Comment: AMS-TeX, ver. 2.1, IBM AT-386, size 16K (ASCII), short versio
The matrix Hamiltonian for hadrons and the role of negative-energy components
The world-line (Fock-Feynman-Schwinger) representation is used for quarks in
arbitrary (vacuum and valence gluon) field to construct the relativistic
Hamiltonian. After averaging the Green's function of the white system
over gluon fields one obtains the relativistic Hamiltonian, which is matrix in
spin indices and contains both positive and negative quark energies. The role
of the latter is studied in the example of the heavy-light meson and the
standard einbein technic is extended to the case of the matrix Hamiltonian.
Comparison with the Dirac equation shows a good agreement of the results. For
arbitrary system the nondiagonal matrix Hamiltonian components are
calculated through hyperfine interaction terms. A general discussion of the
role of negative energy components is given in conclusion.Comment: 29 pages, no figure
Analytic calculation of field-strength correlators
Field correlators are expressed using background field formalism through the
gluelump Green's functions. The latter are obtained in the path integral and
Hamiltonian formalism. As a result behaviour of field correlators is obtained
at small and large distances both for perturbative and nonperturbative parts.
The latter decay exponentially at large distances and are finite at x=0, in
agreement with OPE and lattice data.Comment: 28 pages, no figures; new material added, misprints correcte
Induced quantum numbers of a magnetic monopole at finite temperature
A Dirac electron field is quantized in the background of a Dirac magnetic
monopole, and the phenomenon of induced quantum numbers in this system is
analyzed. We show that, in addition to electric charge, also squares of orbital
angular momentum, spin, and total angular momentum are induced. The functional
dependence of these quantities on the temperature and the CP-violating vacuum
angle is determined. Thermal quadratic fluctuations of charge and squared total
angular momentum, as well as the correlation between them and their
correlations with squared orbital angular momentum and squared spin, are
examined. We find the conditions when charge and squared total angular momentum
at zero temperature are sharp quantum observables rather than mere quantum
averages.Comment: 24 pages, minor grammatical changes, journal versio
Contextual approach to quantum mechanics and the theory of the fundamental prespace
We constructed a Hilbert space representation of a contextual Kolmogorov
model. This representation is based on two fundamental observables -- in the
standard quantum model these are position and momentum observables. This
representation has all distinguishing features of the quantum model. Thus in
spite all ``No-Go'' theorems (e.g., von Neumann, Kochen and Specker,..., Bell)
we found the realist basis for quantum mechanics. Our representation is not
standard model with hidden variables. In particular, this is not a reduction of
quantum model to the classical one. Moreover, we see that such a reduction is
even in principle impossible. This impossibility is not a consequence of a
mathematical theorem but it follows from the physical structure of the model.
By our model quantum states are very rough images of domains in the space of
fundamental parameters - PRESPACE. Those domains represent complexes of
physical conditions. By our model both classical and quantum physics describe
REDUCTION of PRESPACE-INFORMATION. Quantum mechanics is not complete. In
particular, there are prespace contexts which can be represented only by a so
called hyperbolic quantum model. We predict violations of the Heisenberg's
uncertainty principle and existence of dispersion free states.Comment: Plenary talk at Conference "Quantum Theory: Reconsideration of
Foundations-2", Vaxjo, 1-6 June, 200
The coupled-channel analysis of the D and D_s mesons
The shift of the p-wave meson mass due to coupling to the DK channel is
calculated without fitting parameters using the chiral Lagrangian. As a result
the original mass 2.490 MeV generically calculated in the
relativistic quark models is shifted down to the experimental value 2317 MeV.
With the same Lagrangian the shift of the radial excited level is much
smaller, while the total width MeV and the width ratio is in
contradiction with the state observed by SELEX group.Comment: 9 pages, 2 figure
Low-frequency internal friction (LFIF) as express-method for identification of cryocrystals in pores of the solids
We show that studying of low-frequency internal friction (LFIF) of solid
samples at low temperatures allows determining the presence of various gases
absorbed, for some reasons, in pores and caverns of the solids. The gases come
over to a solid state (cryocrystals) and exist in the pores under corresponding
thermodynamic conditions giving an additional contribution to the LFIF spectra.
The spectra reflect the special points of the gases (temperatures of melting or
phase transitions). This information gives a real opportunity for
identification of gas in the matrix, i.e. the studied solids. This may be of
great importance for investigations of cosmic or geological samples, for
instance, asteroids, meteorites, rock formations, etc. The LFIF method allows
identification of gas media surrounding the studied sample.Comment: 14 pages, 8 figures, 39 ref
- …
