1,110 research outputs found
On the solutions of the Schrodinger equation with some molecular potentials: wave function ansatz
Making an ansatz to the wave function, the exact solutions of the %
-dimensional radial Schrodinger equation with some molecular potentials like
pseudoharmonic and modified Kratzer potentials are obtained. The restriction on
the parameters of the given potential, and are also given,
where depends on a linear combination of the angular momentum quantum
number and the spatial dimensions and is a parameter in
the ansatz to the wave function. On inserting D=3, we find that the bound state
eigensolutions recover their standard analytical forms in literature.Comment: 14 page
Explaining Why the u and d Quark Masses are Similar
An approach is suggested for modeling quark and lepton masses and mixing in
the context of grand unified theories that explains the curious fact that m_u ~
m_d even though m_t >> m_b. The structure of the quark mass matrices is such as
to allow a non-Peccei-Quinn solution of the Strong CP Problem.Comment: 11 pages, ReVTeX
Seleção de espigas e debulha das sementes de milho (Zea mays L.): I- efeitos sobre a qualidade física e infestação por insetos
This work had the objective to verify the effects of ear selection and of corn seed thrashing, on their physical quality and insect infestation. Seeds from four fields of seed production, grown in the 1985/86 cropping season were sampled and thrashed (by hand and and mechanically). The results obtained, showed that the seeds derived from the mechanical thrashing at the field showed higher occurrence of mechanical damage than those thrashed under controlled condictions. The selection of ears with corn husk, performed at the field, did not decrease insect infestation and did not to improve the quality of seeds.O presente trabalho, teve como objetivo verificar os efeitos da seleção de espigas e da debulha das sementes de milho, realizada no campo e na unidade de beneficiamento de sementes, sobre a qualidade física e infestação por insetos. Para tanto, foram utilizadas sementes de quatro campos de produção de sementes fiscalizadas da safra 1985/86. As espigas amostradas, foram submetidas às debulhas manual e mecânica (debulhador estacionário acoplado ao trator no próprio local de produção e debulhador da unidade de beneficiamento de sementes da companhia produtora), com e sem seleção de espigas. Os resultados obtidos mostraram que as sementes provenientes da debulha realizada mecanicamente no campo apresentaram maior incidência de danos mecânicos. A seleção das espigas com palha, realizada no campo, não foi eficiente para reduzir a infestação por insetos e nem melhorou a qualidade das sementes
Obtaining the large angle MSW solution to the solar neutrino problem in models
The large mixing angle (LMA) MSW solution to the solar neutrino problem seems
favored by the data at the moment over the small mixing angle (SMA) MSW
solution and the vacuum (VAC) solution. In this paper the various main types of
models of neutrino masses and mixings are studied from the point of view of how
naturally they can give the LMA solution. Special attention is given to a very
simple type of "lopsided" SU(5) model.Comment: 29 pages, 2 Postscript figure
Family Unification with SO(10)
Unification based on the group SO(10)^3 \times S_3 is studied. Each family
has its own SO(10) group, and the S_3 permutes the three families and SO(10)
factors. This is the maximal local symmetry for the known fermions. Family
unification is achieved in the sense that all known fermions are in a single
irreducible multiplet of the symmetry. The symmetry suppresses SUSY flavor
changing effects by making all squarks and sleptons degenerate in the symmetry
limit. Doublet-triplet splitting can arise simply, and non-trivial structure of
the quark and lepton masses emerges from the gauge symmetry, including the
"doubly lopsided" form.Comment: 11 pages, references adde
Relativistic Description of Exclusive Deuteron Breakup Reactions
The exclusive deuteron break-up reaction is analyzed within a covariant
approach based on the Bethe-Salpeter equation with realistic meson-exchange
interaction. Relativistic effects in the cross section, tensor analyzing power
and polarization transfer are investigated in explicit form. Results of
numerical calculations are presented for kinematical conditions in forthcoming
p + D reactions at COSY.Comment: 10 LaTeX pages, 4 eps-figure
A General Approach for the Exact Solution of the Schrodinger Equation
The Schr\"{o}dinger equation is solved exactly for some well known
potentials. Solutions are obtained reducing the Schr\"{o}dinger equation into a
second order differential equation by using an appropriate coordinate
transformation. The Nikiforov-Uvarov method is used in the calculations to get
energy eigenvalues and the corresponding wave functions.Comment: 20 page
Lepton Flavor Violation in the SUSY-GUT Models with Lopsided Mass Matrix
The tiny neutrino masses measured in the neutrino oscillation experiments can
be naturally explained by the supersymmetric see-saw mechanism. If the
supersymmetry breaking is mediated by gravity, the see-saw models may predict
observable lepton flavor violating effects. In this work, we investigate the
lepton flavor violating process in the kind of neutrino mass
models based on the idea of the ``lopsided'' form of the charged lepton mass
matrix. The constraints set by the muon anomalous magnetic moment are taken
into account. We find the present models generally predict a much larger
branching ratio of than the experimental limit. Conversely,
this process may give strong constraint on the lepton flavor structure.
Following this constraint we then find a new kind of the charged lepton mass
matrix. The feature of the structure is that both the elements between the 2-3
and 1-3 generations are ``lopsided''. This structure produces a very small 1-3
mixing and a large 1-2 mixing in the charged lepton sector, which naturally
leads to small and the LMA solution for the solar neutrino
problem.Comment: 24 pages, 8 figure
Possible Flavor Mixing Structures of Lepton Mass Matrices
To search for possible textures of lepton mass matrices, we systematically
examine flavor mixing structures which can lead to large lepton mixing angles.
We find out 37 mixing patterns are consistent with experimental data, taking
into account phase factors in the mixing matrices. Only six of the patterns can
explain the observed data without any tuning of parameters, while the others
need particular choices for the phase values. It is found that these six mixing
patterns are those predicted by the models which have been proposed to account
for fermion mass hierarchies. On the other hand, the others may give new flavor
mixing structures of lepton mass matrices and therefore new possibilities of
model construction.Comment: 21 page
Scale-free memory model for multiagent reinforcement learning. Mean field approximation and rock-paper-scissors dynamics
A continuous time model for multiagent systems governed by reinforcement
learning with scale-free memory is developed. The agents are assumed to act
independently of one another in optimizing their choice of possible actions via
trial-and-error search. To gain awareness about the action value the agents
accumulate in their memory the rewards obtained from taking a specific action
at each moment of time. The contribution of the rewards in the past to the
agent current perception of action value is described by an integral operator
with a power-law kernel. Finally a fractional differential equation governing
the system dynamics is obtained. The agents are considered to interact with one
another implicitly via the reward of one agent depending on the choice of the
other agents. The pairwise interaction model is adopted to describe this
effect. As a specific example of systems with non-transitive interactions, a
two agent and three agent systems of the rock-paper-scissors type are analyzed
in detail, including the stability analysis and numerical simulation.
Scale-free memory is demonstrated to cause complex dynamics of the systems at
hand. In particular, it is shown that there can be simultaneously two modes of
the system instability undergoing subcritical and supercritical bifurcation,
with the latter one exhibiting anomalous oscillations with the amplitude and
period growing with time. Besides, the instability onset via this supercritical
mode may be regarded as "altruism self-organization". For the three agent
system the instability dynamics is found to be rather irregular and can be
composed of alternate fragments of oscillations different in their properties.Comment: 17 pages, 7 figur
- …