69,976 research outputs found
Unbroken supersymmetry in the Aharonov-Casher effect
We consider the problem of the bound states of a spin 1/2 chargless particle
in a given Aharonov-Casher configuration. To this end we recast the description
of the system in a supersymmetric form. Then the basic physical requirements
for unbroken supersymmetry are established. We comment on the possibility of
neutron confinement in this system
Dilaton in a soft-wall holographic approach to mesons and baryons
We discuss a holographic soft-wall model developed for the description of
mesons and baryons with adjustable quantum numbers n, J, L, S. This approach is
based on an action which describes hadrons with broken conformal invariance and
which incorporates confinement through the presence of a background dilaton
field. We show that in the case of the bound-state problem (hadronic mass
spectrum) two versions of the model with a positive and negative dilaton
profile are equivalent to each other by a special transformation of the bulk
field. We also comment on recent works which discuss the dilaton sign in the
context of soft-wall approaches.Comment: 21 pages, accepted for publication in Phys. Rev.
A Relativistic Quark Model for Mesons with an Instanton-Induced Interaction
We present new results of a relativistic quark model based on the
Bethe-Salpeter equation in its instantaneous approximation. Assuming a linearly
rising confinement potential with an appropriate spinorial structure in Dirac
space and adopting a residual interaction based on instanton effects, we can
compute masses of the light mesons up to highest observed angular momenta with
a natural solution of the problem. The calculated ground states masses
and the radial excitations describe the experimental results well. In this
paper, we will also discuss our results concerning numerous meson decay
properties. For processes like and
at various photon virtualities, we find a good agreement
with experimental data. We will also comment on the form factors of the
decay and on the decay constants of the , and
mesons. For the sake of completeness, we will furthermore present the
electromagnetic form factors of the charged and mesons as well as a
comparison of the radiative meson decay widths with the most recent
experimental data.Comment: 30 pages including 10 tables and 16 figures; submitted to Eur. Phys.
J. A; misprints correcte
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