15,447 research outputs found
Is there New Physics in B Decays ?
Rare decays of the meson are sensitive to new physics effects. Several
experimental results on these decays have been difficult to understand within
the standard model (SM) though more precise measurements and a better
understanding of SM theory predictions are needed before any firm conclusions
can be drawn. In this talk we try to understand the present data assuming the
presence of new physics. We find that the data points to new physics of an
extended Higgs sector and we present a two higgs doublet model with a 2-3
flavor symmetry in the down type quark sector that can explain the deviations
from standard model reported in several rare B decays.Comment: 8 pages, Talk presented at Theory Canada II, Perimeter Institute,
Waterloo, Canada. New references added and update
On the Observability of "Invisible" / "Nearly Invisible" Charginos
It is shown that if the charginos decay into very soft leptons or hadrons +
due to degeneracy/ near- degeneracy with the LSP or the sneutrino,
the observability of the recently proposed signal via the single photon (+ soft
particles) + channel crucially depends on the magnitude of the \SNU
mass due to destructive interferences in the matrix element squared. If the
\SNU's and, consequently, left-sleptons are relatively light, the size of the
signal, previously computed in the limit \MSNU \to \infty only, is
drastically reduced. We present the formula for the signal cross section in a
model independent way and discuss the observability of the signal at LEP 192
and NLC energies.Comment: 27 pages, Late
Embedding approach for dynamical mean field theory of strongly correlated heterostructures
We present an embedding approach based on localized basis functions which
permits an efficient application of the dynamical mean field theory (DMFT) to
inhomogeneous correlated materials, such as semi-infinite surfaces and
heterostructures. In this scheme, the semi-infinite substrate leads connected
to both sides of the central region of interest are represented via complex,
energy-dependent embedding potentials that incorporate one-electron as well as
many-body effects within the substrates. As a result, the number of layers
which must be treated explicitly in the layer-coupled DMFT equation is greatly
reduced. To illustrate the usefulness of this approach, we present numerical
results for strongly correlated surfaces, interfaces, and heterostructures of
the single-band Hubbard model.Comment: 8 pages, 4 figures; typos correcte
A prohibition of equilibrium spin currents in multi-terminal ballistic devices
We show that in the multi-terminal ballistic devices with intrinsic
spin-orbit interaction connected to normal metal contacts there are no
equilibrium spin currents present at any given electron energy. Obviously, this
statement holds also after the integration over all occupied states. Based on
the proof of this fact, a number of scenarios involving nonequilibrium spin
currents is identified and further analyzed. In particular, it is shown that an
arbitrary two-terminal device cannot polarize transient current. The same is
true for the output terminal of an N-terminal device when all N-1 inputs are
connected in parallel.Comment: 3 pages, 1 figure; presented at the DARPA SPinS review (#Th-19), San
Francisco, CA, October 25-28, 200
Economics of different craft - gear combination in Orissa coast
After declaration of Exclusive Econonomic
Zone, the Govt. of India took
lot of developmental programmes in capture
fisheries. But it is very difficult to
formulate as well as to implement any
programme unless and until we know the
existing position prevailing in different
coastal areas
Productivity, profitability and income distribution in capture fishery - a case study in Orissa coast
In the literature on marine and inland fisheries very little attention has been focused on income generation by various craft-gear combinations, their productivity and the extent, nature and causes of fluctuations in their incomes. This study of the Orissa coast explores the consequences of mechanisation on income distribution between mechanised and non-mechanised fishing units
Responses of stiffened plates with varying depth of stiffeners under uniform lateral loads
The main portion of ship’s structure is usually composed of stiffened plates. Under various loads
applied to a ship, such as those due to cargo, buoyancy and waves, these stiffened plates are
subjected to combined in plane and lateral loads. Longitudinal stiffeners attached to the plates
may significantly increase the overall buckling loads of the resultant stiffened structures. In this
work, eigen-buckling responses for a series of rectangular perfectly flat plates and longitudinally
stiffened plates subjected to in plane axial forces for different depth of stiffeners are derived by
finite element approach using general purpose software (ANSYS). Finally stiffener arrangements
are explained in explicit form based on the results of numerical investigations of the non-linear
behaviour of plates and stiffened plates
Optimization of Process Parameters by Reliability-Based Uncertainty Modeling of Cold Rolling Process
Metal working processes can often be expressed in a reliability format. Information about present and anticipated reliabilities in metallurgical processes, in conjunction with decision models, provides a rational and powerful decision-making tool. In practice uncertainties arise in predicting service or lifetime loads in considering the variability in material properties, workmanship, process dimensions, environmental conditions, inspection test data, maintenance and so on. A wide range of materials with different elastic moduli, yield stresses, strain hardening and friction co-efficient constitute specific characteristics in a metal working process. Thus a metal working process may be defined as a collection of one or more related objects. Consequently, decisions related to rolling processes are based on uncertain or incomplete information. Finite element based process simulation can offer valuable guidelines on how the current process parameters should be modified to meet the requirements on the process and the product. This work represents a continued effort towards developing a sound methodology for modelling uncertainties in rolling process with reference to the reliability assessment. Based on the information obtained from the finite element simulation, investigations are conducted to assess the structural integrity of final product. The objective of this work is to use probabilistic methods to represent sources of uncertainty and to attain optimum set of points of rolling by iteration to achieve controlled microstructure of the finished product
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