177 research outputs found
NLO QCD corrections to processes with multiple electroweak bosons
The VBFNLO program package is a collection of Monte Carlo programs for the
calculation of NLO QCD corrections to vector boson fusion cross sections,
double and triple vector boson production, or the production of two electroweak
bosons in association with an additional jet. An overview is given of the
processes and features implemented in VBFNLO. WWgamma and Wgamma jet production
are discussed as examples.Comment: 6 pages, 3 figures; talk given at RADCOR 2009 - 9th International
Symposium on Radiative Corrections (Applications of Quantum Field Theory to
Phenomenology), October 25 - 30 2009, Ascona, Switzerlan
Next-to-leading order QCD corrections to W+W- production via vector-boson fusion
Vector-boson fusion processes constitute an important class of reactions at
hadron colliders, both for signals and backgrounds of new physics in the
electroweak interactions.
We consider what is commonly referred to as W+W- production via vector-boson
fusion (with subsequent leptonic decay of the Ws), or, more precisely, e+ nu_e
mu- nubar_mu + 2 jets production in proton-proton scattering, with all resonant
and non-resonant Feynman diagrams and spin correlations of the final-state
leptons included, in the phase-space regions which are dominated by t-channel
electroweak-boson exchange.
We compute the next-to-leading order QCD corrections to this process, at
order alpha^6 alpha_s.
The QCD corrections are modest, changing total cross sections by less than
10%. Remaining scale uncertainties are below 2%. A fully-flexible
next-to-leading order partonic Monte Carlo program allows to demonstrate these
features for cross sections within typical vector-boson-fusion acceptance cuts.
Modest corrections are also found for distributions.Comment: 29 pages, 14 figure
A compact spectral camera for VIS-NIR imaging
This paper describes the design of a spectro-photo/radio-metric camera, that can be used in both portable and in-situ applications, whose compactness is made possible by a suitable image spectral scanning scheme based on a Linearly Variable Filter (LVF). Such filter is able to operate continuously from 400 nm to 2500 nm, allowing the hyper-spectral imaging from visible to near infrared. In traditional scanners the whole apparatus is moved along a path as long as the scene, whereas in this instrument the camera body is still and the LVF it is the only moving part. This solution allows a compact design and an easily portable instrument
A motivational approach to support healthy habits in long-term child–robot interaction
We examine the use of role-switching as an intrinsic motivational mechanism to increase engagement in long-term child–robot interaction. The present study describes a learning framework where children between 9 and 11-years-old interact with a robot to improve their knowledge and habits with regards to healthy life-styles. Experiments were carried out in Italy where 41 children were divided in three groups interacting with: (i) a robot with a role-switching mechanism, (ii) a robot without a role-switching mechanism and (iii) an interactive video. Additionally, a control group composed of 43 more children, who were not exposed to any interactive approach, was used as a baseline of the study. During the intervention period, the three groups were exposed to three interactive sessions once a week. The aim of the study was to find any difference in healthy-habits acquisition based on alternative interactive systems, and to evaluate the effectiveness of the role-switch approach as a trigger for engagement and motivation while interacting with a robot. The results provide evidence that the rate of children adopting healthy habits during the intervention period was higher for those interacting with a robot. Moreover, alignment with the robot behaviour and achievement of higher engagement levels were also observed for those children interacting with the robot that used the role-switching mechanism. This supports the notion that role-switching facilitates sustained long-interactions between a child and a robot
Release Note -- Vbfnlo-2.6.0
Vbfnlo is a flexible parton level Monte Carlo program for the simulation of
vector boson fusion (VBF), double and triple vector boson (plus jet) production
in hadronic collisions at next-to-leading order (NLO) in the strong coupling
constant, as well as Higgs boson plus two jet production via gluon fusion at
the one-loop level. This note briefly describes the main additional features
and processes that have been added in the new release -- Vbfnlo Version 2.6.0.
At NLO QCD diboson production (W\gamma, WZ, ZZ, Z\gamma and \gamma\gamma),
same-sign W pair production via vector boson fusion and the process
W\gamma\gamma j have been implemented (for which one-loop tensor integrals up
to six-point functions are included). In addition, gluon induced diboson
production can be studied separately at the leading order (one-loop) level. The
diboson processes WW, WZ and W\gamma can be run with anomalous gauge boson
couplings, and anomalous couplings between a Higgs and a pair of gauge bosons
is included in WW, ZZ, Z\gamma and \gamma\gamma diboson production. The code
has also been extended to include anomalous gauge boson couplings for single
vector boson production via VBF, and a spin-2 model has been implemented for
diboson pair production via vector boson fusion.Comment: 14 pages, 6 tables; new code available at
http://www-itp.particle.uni-karlsruhe.de/vbfnlo
Pros and cons of using a computer vision system for color evaluation of meat and meat products
The ability of a computer vision system to evaluate the color of meat and meat products was investigated by a comparison study with color measurements from a traditional colorimeter. Pros and cons of using a computer vision system for color evaluation of meat and meat products were evaluated. Statistical analysis revealed significant differences between the instrumental values in all three dimensions (L*, a*, b*) between the computer vision system and the colorimeter. The computer vision system-generated colors were perceived as being more similar to the sample of the meat products visualized on the monitor, compared to colorimeter-generated colors in all (100%) individual trials performed. The use of the computer vision system is, therefore, considered a superior and less expensive alternative to the traditional method for measuring color of meat and meat products. The disadvantages of the computer vision system are its size, which makes it stationary, and the lack of official manufacturers that can provide ready-to-use systems. This type of computerized system still demands experts for its assembly and utilization
Standard Model Higgs boson production in association with a top anti-top pair at NLO with parton showering
We present predictions for the production cross section of a Standard Model
Higgs boson in association with a top-antitop pair at next-to-leading order
accuracy using matrix elements obtained from the HELAC-Oneloop package. The NLO
prediction was interfaced to the PYTHIA and HERWIG shower Monte Carlo programs
with the help of POWHEG-Box, allowing for decays of massive particles,
showering and hadronization, thus leading to final results at the hadron level.Comment: 14 pages, 9 figure
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