1,684 research outputs found
Probing the indefinite CP nature of the Higgs Boson through decay distributions in the process
The recently discovered scalar resonance at the LHC is now almost confirmed
to be a Higgs Boson, whose CP properties are yet to be established. At the ILC
with and without polarized beams, it may be possible to probe these properties
at high precision. In this work, we study the possibility of probing departures
from the pure CP-even case, by using the decay distributions in the process
, with mainly decaying into a
pair. We have compared the case of a minimal extension of the SM case (Model I)
with an additional pseudoscalar degree of freedom, with a more realistic case
namely the CP-violating Two-Higgs Doublet Model (Model II) that permits a more
general description of the couplings. We have considered the ILC with
\,GeV and integrated luminosity of . Our
main findings are that even in the case of small departures from the CP-even
case, the decay distributions are sensitive to the presence of a CP-odd
component in Model II, while it is difficult to probe these departures in Model
I unless the pseudoscalar component is very large. Noting that the proposed
degrees of beam polarization increases the statistics, the process demonstrates
the effective role of beam polarization in studies beyond the Standard Model.
Further, our study shows that an indefinite CP Higgs would be a sensitive
laboratory to physics beyond the SM.Comment: 14 pages using revtex, 10 figures, corresponds to version accepted
for publication in Phys. Rev. D.; compared to v1, discussion extended, figure
added, table added, section reorganize
Realization of Resistorless Lossless Positive and Negative Grounded Inductor Simulators Using Single ZC-CCCITA
This paper is in continuation with the very recent work of Prasad et al. [14], wherein new realizations of grounded and floating positive inductor simulator using current differencing transconductance amplifier (CDTA) are reported. The focus of the paper is to provide alternate realizations of lossless, both positive and negative inductor simulators (PIS and NIS) in grounded form using z-copy current-controlled current inverting transconductance amplifier (ZC-CCCITA), which can be considered as a derivative of CDTA, wherein the current differencing unit (CDU) is reduced to a current-controlled current inverting unit. We demonstrate that only a single ZC-CCCITA and one grounded capacitor are sufficient to realize grounded lossless PIS or NIS. The proposed circuits are resistorless whose parameters can be controlled through the bias currents. The workability of the proposed PIS is validated by SPICE simulations on three RLC prototypes
Further results on I-limit superior and limit inferior
In this paper we obtain (after the works of Demirci) some further properties of I-limit superior and I-limit inferior and obtain the I-analogue of Cauchy criterion of convergence of a sequence of real numbers
Top Yukawa coupling measurement with indefinite CP Higgs in
We consider the issue of the top quark Yukawa coupling measurement in a model
in dependent and general case with the inclusion of CP-violation in the
coupling. Arguably the best process to study this coupling is the associa ted
production of Higgs boson along with a pair in a machine like the
International Linear Collider (ILC). While detailed analyses of the sensitivity
of the measurement assuming a Standard Model (SM) - like coupling are available
in the context of ILC, conclude that th e coupling could be pinned down at
about 10\% level with modest luminosity, our investigations show that the
scenario could be different in case of a more general coupling. The modified
Lorentz structure resulting in a changed functional dependence of the cross
section on the couplin g, along with the difference in the cross section itself
leads to considerable deviation in the sensitivity. Our studies with an ILC of
center of mass energies of 500 GeV, 800 GeV and 1000 GeV show that moderate
CP-mixing in the Higgs sector could change the sensitivity to about 20\ %,
while it could be worsened to 75\% in cases which could accommodate more
dramatic changes in the coupling. While detailed considerations of the decay
distributions point to a need for a relook at the analysis strategy followed
for the case of SM such as for a model independent analysis of the top quark
Yukawa coupling measurement. This study strongly suggests that, a joint
analysis of the CP properties and the Yukawa coupling measurement would be the
way forward at the ILC and that caution must be excercised in the measurem ent
of the Yukawa couplings and the conclusions drawn from it.Comment: 18 pages, 7 figures, uses revte
Phase Transition in the ABC Model
Recent studies have shown that one-dimensional driven systems can exhibit
phase separation even if the dynamics is governed by local rules. The ABC
model, which comprises three particle species that diffuse asymmetrically
around a ring, shows anomalous coarsening into a phase separated steady state.
In the limiting case in which the dynamics is symmetric and the parameter
describing the asymmetry tends to one, no phase separation occurs and the
steady state of the system is disordered. In the present work we consider the
weak asymmetry regime where is the system size and
study how the disordered state is approached. In the case of equal densities,
we find that the system exhibits a second order phase transition at some
nonzero .
The value of and the optimal profiles can be
obtained by writing the exact large deviation functional. For nonequal
densities, we write down mean field equations and analyze some of their
predictions.Comment: 18 pages, 3 figure
Defect Detection in Weld Joints by Infrared Thermography
The objective of this present paper is to evaluate the effectiveness of infrared thermography (IRT) as a non-contact, fast and reliable non-destructive evaluation procedure for detection and quantification of defects in weld joints. In the present work, a friction stir welded (FSW) joint of two aluminum plates and three 316 LN stain-less steel (SS) weld-joints with lack of penetration (LOP),
lack of fusion (LOF) and tungsten inclusion (TI) defects respectively, were inspected using IRT and digital radio-graphy (DRG). Using active thermography methods, a sub-surface tunnel defect along the weld line was successfully
detected in the FSW joint and its length and width were estimated by suitable pixel calibration. Using lock-in thermography, optimum frequencies were determined for each of the specimens and defect-depths were estimated. Tempe-rature fall of the defect region and defect-free region were monitored as a function of time and it was found that the rate of temperature fall in the former case is slower than that in the latter one. Results from both the tech-niques, i.e., IRT and DRG were found to be in good agree-ment with each other in all the cases. Advantage of IRT is that it provides depth information also
Condensation Transitions in Two Species Zero-Range Process
We study condensation transitions in the steady state of a zero-range process
with two species of particles. The steady state is exactly soluble -- it is
given by a factorised form provided the dynamics satisfy certain constraints --
and we exploit this to derive the phase diagram for a quite general choice of
dynamics. This phase diagram contains a variety of new mechanisms of condensate
formation, and a novel phase in which the condensate of one of the particle
species is sustained by a `weak' condensate of particles of the other species.
We also demonstrate how a single particle of one of the species (which plays
the role of a defect particle) can induce Bose-Einstein condensation above a
critical density of particles of the other species.Comment: 17 pages, 4 Postscript figure
Phase Separation in One-Dimensional Driven Diffusive Systems
A driven diffusive model of three types of particles that exhibits phase
separation on a ring is introduced. The dynamics is local and comprises nearest
neighbor exchanges that conserve each of the three species. For the case in
which the three densities are equal, it is shown that the model obeys detailed
balance. The Hamiltonian governing the steady state distribution in this case
is given and is found to have long range asymmetric interactions. The partition
sum and bounds on some correlation functions are calculated analytically
demonstrating phase separation.Comment: 4 Pages, Revtex, 2 Figures included, Submitted to Physical Review
Letter
Singular Scaling Functions in Clustering Phenomena
We study clustering in a stochastic system of particles sliding down a
fluctuating surface in one and two dimensions. In steady state, the
density-density correlation function is a scaling function of separation and
system size.This scaling function is singular for small argument -- it exhibits
a cusp singularity for particles with mutual exclusion, and a divergence for
noninteracting particles. The steady state is characterized by giant
fluctuations which do not damp down in the thermodynamic limit. The
autocorrelation function is a singular scaling function of time and system
size. The scaling properties are surprisingly similar to those for particles
moving in a quenched disordered environment that results if the surface is
frozen.Comment: 8 pages, 3 figures, Invited talk delivered at Statphys 23, Genova,
July 200
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