3,668 research outputs found
Auxiliary field method and analytical solutions of the Schr\"{o}dinger equation with exponential potentials
The auxiliary field method is a new and efficient way to compute approximate
analytical eigenenergies and eigenvectors of the Schr\"{o}dinger equation. This
method has already been successfully applied to the case of central potentials
of power-law and logarithmic forms. In the present work, we show that the
Schr\"{o}dinger equation with exponential potentials of the form can also be analytically solved by using the
auxiliary field method. Formulae giving the critical heights and the energy
levels of these potentials are presented. Special attention is drawn on the
Yukawa potential and the pure exponential one
Electromagnetic splitting for mesons and baryons using dressed constituent quarks
Electromagnetic splittings for mesons and baryons are calculated in a
formalism where the constituent quarks are considered as dressed
quasiparticles. The electromagnetic interaction, which contains coulomb,
contact, and hyperfine terms, is folded with the quark electrical density. Two
different types of strong potentials are considered. Numerical treatment is
done very carefully and several approximations are discussed in detail. Our
model contains only one free parameter and the agreement with experimental data
is reasonable although it seems very difficult to obtain a perfect description
in any case.Comment: 14 pages, Revised published versio
Towers of hybrid mesons
A hybrid meson is a quark-antiquark pair in which, contrary to ordinary
mesons, the gluon field is in an excited state. In the framework of constituent
models, the interaction potential is assumed to be the energy of an excited
string. An approximate, but accurate, analytical solution of the
Schr\"{o}dinger equation with such a potential is presented. When applied to
hybrid charmonia and bottomonia, towers of states are predicted in which the
masses are a linear function of a harmonic oscillator band number for the
quark-antiquark pair. Such a formula could be a reliable guide for the
experimental detection of heavy hybrid mesons.Comment: 3 figure
Further developments for the auxiliary field method
The auxiliary field method is a technique to obtain approximate closed
formulae for the solutions of both nonrelativistic and semirelativistic
eigenequations in quantum mechanics. For a many-body Hamiltonian describing
identical particles, it is shown that the approximate eigenvalues can be
written as the sum of the kinetic operator evaluated at a mean momentum
and of the potential energy computed at a mean distance . The quantities
and are linked by a simple relation depending on the quantum
numbers of the state considered and are determined by an equation which is
linked to the generalized virial theorem. The (anti)variational character of
the method is discussed, as well as its connection with the perturbation
theory. For a nonrelativistic kinematics, general results are obtained for the
structure of critical coupling constants for potentials with a finite number of
bound states.Comment: New improved presentatio
A semiclassical model of light mesons
The dominantly orbital state description is applied to the study of light
mesons. The effective Hamiltonian is characterized by a relativistic kinematics
supplemented by the usual funnel potential with a mixed scalar and vector
confinement. The influence of two different finite quark masses and potential
parameters on Regge and vibrational trajectories is discussed.Comment: 1 figur
Tetraquark bound states in a constituent quark model and the nature of the a_0(980) and f_0(980)
In this work we study tetraquark bound states in the framework of the
constituent quark model of Ref. [2], which has been used for the description of
non-strange two- and three-baryon systems and later on applied to the hadron
spectra.Comment: Contribution to the MESON 2002 Workshop. Krakow 24-28 May 200
Del styling al streamline
El styling puede considerarse como el primer estilo
propiamente estadounidense. No respondía a cánones teóricos, y sí a las
exigencias del mercado. Sus diseños entraban en consonancia con los
procesos de producción, lo que permitia abaratar costes y estar al alcance
de más sectores de población. Su justificación teórica llegó en el momento
en que se aplicó la aerodinámica a sus diseños, dando lugar al streamline.ABSTRACT : The styling can be considered the first style properly
American. It did not respond to theoretical principles, but to the demands
of the market. Their designs were in line with the production processes,
which made it possible to lower costs and reach more sectors of the
population. Its theoretical justification came at the time that the
aerodynamics were applied to its designs, giving rise to the streamline
designs.info:eu-repo/semantics/publishedVersio
A (p/E) Calculation of Strong Pionic Decays of Baryons
Strong pionic decays of baryons are studied in a non-relativistic quark model
framework via a convergent (p/E) expansion of the transition operator. Results
are compared to the ones obtained within a more conventional (p/m) expansion.Comment: 16 pages, LaTeX, using amssymb.st
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