5,052 research outputs found
A Proposal of a Renormalization Group Transformation for Lattice Field Theories
We propose a new Real Space Renormalization Group transformation useful for
Monte Carlo calculations in theories with global or local symmetries. From
relaxation arguments we define the block-spin transformation with two tunable
free parameters, adapted to the system's action. Varying them it is possible to
place the fixed point very close to the simulation point. We show how the
method works in a simple model with global symmetry: the three dimensional XY
model.Comment: 26 pages, uuencoded compressed postscript single file, 8 figures
include
Probing the " from " supersymmetric standard model with displaced multileptons from the decay of a Higgs boson at the LHC
The " from " supersymmetric standard model (SSM) cures the
-problem and concurrently reproduces measured neutrino data by using a set
of usual right-handed neutrino superfields. Recently, the LHC has revealed the
first scalar boson which naturally makes it tempting to test SSM in the
light of this new discovery. We show that this new scalar while decaying to a
pair of unstable long-lived neutralinos, can lead to a distinct signal with
non-prompt multileptons. With concomitant collider analysis we show that this
signal provides an unmistakable signature of the model, pronounced with light
neutralinos. Evidence of this signal is well envisaged with sophisticated
displaced vertex analysis, which deserves experimental attention.Comment: 5 pages, 3 figures, title, text, abstract and references modifie
Hunting physics beyond the standard model with unusual and decays
Nonstandard on-shell decays of and bosons are possible within the
framework of extended supersymmetric models, i.e., with singlet states and/or
new couplings compared to the minimal supersymmetric standard model. These
modes are typically encountered in regions of the parameter space with light
singlet-like scalars, pseudoscalars, and neutralinos. In this letter we
emphasize how these states can lead to novel signals at colliders from - or
-boson decays with prompt or displaced multileptons/tau
jets/jets/photons in the final states. These new modes would give distinct
evidence of new physics even when direct searches remain unsuccessful. We
discuss the possibilities of probing these new signals using the existing LHC
run-I data set. We also address the same in the context of the LHC run-II, as
well as for the future colliders. We exemplify our observations with the "
from " supersymmetric standard model, where three generations of
right-handed neutrino superfields are used to solve shortcomings of the minimal
supersymmetric standard model. We also extend our discussion for other variants
of supersymmetric models that can accommodate similar signatures.Comment: New discussions and references added, 8 pages, 1 figure, matches with
the published version in Phys. Rev.
Effect of Dilution on First Order Transitions: The Three Dimensional Three States Potts Model
We have studied numerically the effect of quenched site dilution on a first
order phase transition in three dimensions. We have simulated the site diluted
three states Potts model studying in detail the second order region of its
phase diagram. We have found that the exponent is compatible with the one
of the three dimensional diluted Ising model whereas the exponent is
definitely different.Comment: RevTex. 6 pages and 6 postscript figure
Continuous improvement integrating technological tools to assertively accelerate decision-making of logistics. Case implemented in a construction materials supplier company
Considering that many of the logistics infrastructure designs around the world are often sup-ported by studies with various computational tools, but most of these solutions are using in isolation and little understandably. Therefore, it is proposed, to develop this research based on a Logistics Reference Model, which will allow, visualize, manage and analyze the different processes and logistical scenarios of the system, with in aim to execute the best cost-benefit strategy in a company dedicated to the distribution of construction materials. By implementing this methodology, the management of the company studied was able to make the best decision for the structuring of its processes in the area of picking and dispatch. The results showed a 50% re-duction in inventory review time, equal an increase in reliability 7% that leaves the company in around location close to 85.68%; a decrease in cycle time in each order between 20% and 40% which positively impacted the customer service level. In addition, a decrease in lead times for the receipt of materials to suppliers was achieved between 15% and 30%, and a decrease in the number of warehouses, went having from 5 independent to maintain one single distribution center
Probing the SSM with light scalars, pseudoscalars and neutralinos from the decay of a SM-like Higgs boson at the LHC
The " from " supersymmetric standard model (SSM) can
accommodate the newly discovered Higgs-like scalar boson with a mass around 125
GeV. This model provides a solution to the -problem and simultaneously
reproduces correct neutrino physics by the simple use of right-handed neutrino
superfields. These new superfields together with the introduced -parity
violation can produce novel and characteristic signatures of the SSM at
the LHC. We explore the signatures produced through two-body Higgs decays into
the new states, provided that these states lie below in the mass spectrum. For
example, a pair produced light neutralinos depending on the associated decay
length can give rise to displaced multi-leptons/taus/jets/photons with
small/moderate missing transverse energy. In the same spirit, a Higgs-like
scalar decaying to a pair of scalars/pseudoscalars can produce final states
with prompt multi-leptons/taus/jets/photons.Comment: 58 pages, 3 figures, three new references added, matches with the
published version in JHE
A combined high-pressure experimental and theoretical study of the electronic band-structure of scheelite-type AWO4 (A = Ca, Sr, Ba, Pb) compounds
The optical-absorption edge of single crystals of CaWO4, SrWO4, BaWO4, and
PbWO4 has been measured under high pressure up to ~20 GPa at room temperature.
From the measurements we have obtained the evolution of the band-gap energy
with pressure. We found a low-pressure range (up to 7-10 GPa) where
alkaline-earth tungstates present a very small Eg pressure dependence (-2.1 <
dEg/dP < 8.9 meV/GPa). In contrast, in the same pressure range, PbWO4 has a
pressure coefficient of -62 meV/GPa. The high-pressure range is characterized
in the four compounds by an abrupt decrease of Eg followed by changes in
dEg/dP. The band-gap collapse is larger than 1.2 eV in BaWO4. We also
calculated the electronic-band structures and their pressure evolution.
Calculations allow us to interpret experiments considering the different
electronic configuration of divalent metals. Changes in the pressure evolution
of Eg are correlated with the occurrence of pressure-induced phase transitions.
The band structures for the low- and high-pressure phases are also reported. No
metallization of any of the compounds is detected in experiments nor is
predicted by calculations.Comment: 26 pages, 1 table, 6 figure
Ianus: an Adpative FPGA Computer
Dedicated machines designed for specific computational algorithms can
outperform conventional computers by several orders of magnitude. In this note
we describe {\it Ianus}, a new generation FPGA based machine and its basic
features: hardware integration and wide reprogrammability. Our goal is to build
a machine that can fully exploit the performance potential of new generation
FPGA devices. We also plan a software platform which simplifies its
programming, in order to extend its intended range of application to a wide
class of interesting and computationally demanding problems. The decision to
develop a dedicated processor is a complex one, involving careful assessment of
its performance lead, during its expected lifetime, over traditional computers,
taking into account their performance increase, as predicted by Moore's law. We
discuss this point in detail
The influence of pre-fermentative maceration and ageing factors on ester profile and marker determination of Pedro Ximenez sparkling wines
The influence of pre-fermentative maceration and ageing factors on the ester profiles of Pedro Ximenez sparkling wines was evaluated. The pre-fermentative maceration consisted of the skin-maceration of musts at 10 degrees C for 6 h. The sparkling wines were produced following the Champenoise method. Samples were monitored at 3, 6 and 9 months of ageing on lees. Sparkling wines with pre fermentative maceration displayed higher contents of ethyl esters of branched acids and cinnamates. Meanwhile, those without maceration showed higher levels of ethyl esters of fatty acids and higher alcohol acetates. The study of statistical interactions elucidated different hydrolytic kinetics and developments in higher alcohol acetates and ethyl esters of branched acids during ageing. The application of a dual criterion based on univariate (ANOVA) and multivariate analyses (OPLS-DA) allowed us to identify new potential volatile markers related to pre-fermentative maceration and ageing time, reported for the first time in sparkling wines
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