3,214 research outputs found
Real CP violation in a simple extension of the standard model
I present a simple three-Higgs-doublet extension of the standard model in
which real CP violation takes place. The strong CP problem is attenuated by
this model.Comment: 8 page
Radiative Kaon Decays and Direct CP Violation
It is stressed that a measurement of the electric dipole amplitude for direct
photon emission in \kpm decays through its interference with inner
bremsstrahlung is important for differentiating among various models. Effects
of amplitude CP violation in the radiative decays of the charged kaon are
analyzed in the Standard Model in conjunction with the large approach. We
point out that gluon and electromagnetic penguin contributions to the
CP-violating asymmetry between the Dalitz plots of \kpm are of equal weight.
The magnitude of CP asymmetry ranges from to when the photon energy in the kaon rest frame varies from 50 MeV to
170 MeV.Comment: Latex, 11 pages, ITP-SB-93-36, IP-ASTP-22-9
Implicit Density Functional Theory
A fermion ground state energy functional is set up in terms of particle
density, relative pair density, and kinetic energy tensor density. It satisfies
a minimum principle if constrained by a complete set of compatibility
conditions. A partial set, which thereby results in a lower bound energy under
minimization, is obtained from the solution of model systems, as well as a
small number of exact sum rules. Prototypical application is made to several
one-dimensional spinless non-interacting models. The effectiveness of "atomic"
constraints on model "molecules" is observed, as well as the structure of
systems with only finitely many bound states.Comment: 9 pages, 4 figure
Role of Scalar Meson Resonances in $K_{L}^{0} \rightarrow \pi^{0} \gamma \gamma Decay
Corrections to decay induced by
scalar meson exchange are studied within chiral perturbation theory. In spite
of bad knowledge of scalar-mesons parameters, the calculated branching ratio
can be changed by a few percent.Comment: 18 pages of text, 2 figures (available upon request); preprint
IJS-TP-16-94 , TUM-T31-63-94
Long distance contribution to decay and terms in CHPT
The long distance contribution to is
calculated using chiral perturbation theory. The leading contribution comes
from tree terms. The branching ratio of the long distance
contribution is found to be of order smaller than the short distance
contributions.Comment: 12 pages, 1 figure (available upon request
A perturbative treatment for the energy levels of neutral atoms
Energy levels of neutral atoms have been re-examined by applying an
alternative perturbative scheme in solving the Schrodinger equation for the
Yukawa potential model with a modified screening parameter. The predicted shell
binding energies are found to be quite accurate over the entire range of the
atomic number up to 84 and compare very well with those obtained within the
framework of hyper-virial-Pade scheme and the method of shifted large-N
expansion. It is observed that the new perturbative method may also be applied
to the other areas of atomic physics.Comment: 18 page
FCNC in left-right symmetric theories and constraints on the right-handed scale
We revise the limits on the FCNC higgses in manifestly left-right symmetric
theories. It is shown that the combination of the Kobayashi-Maskawa
CP-violation with the tree level higgs exchange gives very large
contribution to the CP-violating parameter. It leads to the new
strong constraint on the FCNC higgs mass, M>50- 100 TeV, enhanced by factor of
the order . Being addressed to the supersymmetric left-right
models, FCNC problem requires both right-handed scale and supersymmetric mass
parameters be heavier than 50 TeV for . The most relaxed case
corresponds to where right-handed scale can be of the
order of few TeV.Comment: 11 pages, latex, 3 figure
The standard model at low energies
The hadronic sector of the standard model at low energies is described by a
non--decoupling effective field theory, chiral perturbation theory. An
introduction is given to the construction of effective chiral Lagrangians, both
in the purely mesonic sector and with inclusion of baryons. The connection
between the relativistic formulation and the heavy baryon approach to chiral
perturbation theory with baryons is reviewed.Comment: Lectures given at the 6th Indian-Summer School on Intermediate Energy
Physics, Prague, Aug. 1993, Latex, 26 pages (with a4.sty), UWThPh-1993-3
A Parametrization for
We discuss various models and Chiral Perturbation Theory results for the
form factors and . We check in how much a simple
parametrization with a few parameters can be used to extract information from
experiment.Comment: 19 pages, 14 figure
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