1,609 research outputs found
Vector Currents of Massive Neutrinos of an Electroweak Nature
The mass of an electroweakly interacting neutrino consists of the electric
and weak parts responsible for the existence of its charge, charge radius, and
magnetic moment. Such connections explain the formation of paraneutrinos, for
example, at the polarized neutrino electroweak scattering by spinless nuclei.
We derive the structural equations that relate the self-components of mass to
charge, charge radius, and magnetic moment of each neutrino as a consequence of
unification of fermions of a definite flavor. They indicate the availability of
neutrino universality and require following its logic in a constancy law
dependence of the size implied from the multiplication of a weak mass of
neutrino by its electric mass. According to this principle, all Dirac neutrinos
of a vector nature, regardless of the difference in their masses, have the same
charge, an identical charge radius, as well as an equal magnetic moment.
Thereby, the possibility appears of establishing the laboratory limits of weak
masses of the investigated types of neutrinos. Finding estimates show clearly
that the earlier measured properties of these particles may testify in favor of
the unified mass structure of their interaction with any of the corresponding
types of gauge fields.Comment: 14 pages, LaTex, Published version in CJ
Low energy chaos in the Fermi-Pasta-Ulam problem
A possibility that in the FPU problem the critical energy for chaos goes to
zero with the increase of the number of particles in the chain is discussed.
The distribution for long linear waves in this regime is found and an estimate
for new border of transition to energy equipartition is given.Comment: revtex, 12 pages, 5 figures, submitted to Nonlinearit
Normal frames and the validity of the equivalence principle
We investigate the validity of the equivalence principle along paths in
gravitational theories based on derivations of the tensor algebra over a
differentiable manifold. We prove the existence of local bases, called normal,
in which the components of the derivations vanish along arbitrary paths. All
such bases are explicitly described. The holonomicity of the normal bases is
considered. The results obtained are applied to the important case of linear
connections and their relationship with the equivalence principle is described.
In particular, any gravitational theory based on tensor derivations which obeys
the equivalence principle along all paths, must be based on a linear
connection.Comment: 14 pages, LaTeX 2e, the package amsfonts is neede
Generalized Phase Rules
For a multi-component system, general formulas are derived for the dimension
of a coexisting region in the phase diagram in various state spaces.Comment: In the revised manuscript, physical meanings of D's are explained by
adding three figures. 10 pages, 3 figure
Corrections to Fermi's Golden Rule in Decays
We analyze the decays utilizing a formulation of
transition rates which explicitly exhibits corrections to Fermi's Golden Rule.
These corrections arise in systems in which the phase space and/or matrix
element varies rapidly with energy, as happens in , which is
just above threshold. We show that the theoretical corrections resolve a
puzzling discrepancy between theory and experiment for the branching
ratio
Covariant hydrodynamic Lyapunov modes and strong stochasticity threshold in Hamiltonian lattices
We scrutinize the reliability of covariant and Gram-Schmidt Lyapunov vectors
for capturing hydrodynamic Lyapunov modes (HLMs) in one-dimensional Hamiltonian
lattices. We show that,in contrast with previous claims, HLMs do exist for any
energy density, so that strong chaos is not essential for the appearance of
genuine (covariant) HLMs. In contrast, Gram-Schmidt Lyapunov vectors lead to
misleading results concerning the existence of HLMs in the case of weak chaos.Comment: 4 pages, 4 figures. Accepted for publication in Physical Review
Three and Four Harmonically Trapped Particles in an Effective Field Theory Framework
We study systems of few two-component fermions interacting via short-range
interactions within a harmonic-oscillator trap. The dominant interactions,
which are two-body, are organized according to the number of derivatives and
defined in a two-body truncated model space made from a bound-state basis.
Leading-order (LO) interactions are solved for exactly using the formalism of
the No-Core Shell Model, whereas corrections are treated as many-body
perturbations. We show explicitly that next-to-LO and next-to-next-to-LO
interactions improve convergence as the model space increases. We present
results at unitarity for three- and four-fermion systems, which show excellent
agreement with the exact solution (for the three-body problem) and results
obtained by others methods (in the four-body case). We also present results for
finite scattering lengths and non-zero range of the interaction, including (at
positive scattering length) observation of a change in the structure of the
three-body ground state and extraction of the atom-dimer scattering length.Comment: 18 pages, 10 figure
Ionization potentials in the limit of large atomic number
By extrapolating the energies of non-relativistic atoms and their ions with
up to 3000 electrons within Kohn-Sham density functional theory, we find that
the ionization potential remains finite and increases across a row, even as
. The local density approximation becomes chemically
accurate (and possibly exact) in some cases. Extended Thomas-Fermi theory
matches the shell-average of both the ionization potential and density change.
Exact results are given in the limit of weak electron-electron repulsion.Comment: 4 pages, 5 figure
Extended Fermi coordinates
We extend the notion of Fermi coordinates to a generalized definition in
which the highest orders are described by arbitrary functions. From this
definition rises a formalism that naturally gives coordinate transformation
formulae. Some examples are developped in which the extended Fermi coordinates
simplify the metric components.Comment: 16 pages, 1 figur
Inelastic final-state interaction
The final-state interaction in multichannel decay processes is sytematically
studied with application to B decay in mind. Since the final-state inteaction
is intrinsically interwoven with the decay interaction in this case, no simple
phase theorem like "Watson's theorem" holds for experimentally observed final
states. We first examine in detail the two-channel problem as a toy-model to
clarify the issues and to remedy common mistakes made in earlier literature.
Realistic multichannel problems are too challenging for quantitative analysis.
To cope with mathematical complexity, we introduce a method of approximation
that is applicable to the case where one prominant inelastic channel dominates
over all others. We illustrate this approximation method in the amplitude of
the decay B to pi K fed by the intermediate states of a charmed meson pair.
Even with our approximation we need more accurate information of strong
interactions than we have now. Nonethless we are able to obtain some insight in
the issue and draw useful conclusions on general fearyres on the strong phases.Comment: The published version. One figure correcte
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