675 research outputs found
Restriction on the energy and luminosity of e+e- storage rings due to beamstrahlung
The role of beamstrahlung in high-energy e+e- storage-ring colliders (SRCs)
is examined. Particle loss due to the emission of single energetic
beamstrahlung photons is shown to impose a fundamental limit on SRC
luminosities at energies 2E_0 >~ 140 GeV for head-on collisions and 2E_0 >~ 40
GeV for crab-waist collisions. With beamstrahlung taken into account, we
explore the viability of SRCs in the E_0=240-500 GeV range, which is of
interest in the precision study of the Higgs boson. At 2E_0=240 GeV, SRCs are
found to be competitive with linear colliders; however, at 2E_0=400-500 GeV,
the attainable SRC luminosity would be a factor 15-25 smaller than desired.Comment: Latex, 5 pages. v2 differs only by minor changes is abstract and
introduction, one reference is added. v3 corresponds to the paper published
in PR
Hybrid Software Development Approaches in Practice: A European Perspective
Agile and traditional development approaches are used in combination in todays software development. To improve the understanding and to provide better guidance for selecting appropriate development approaches, it is important to analyze such combinations in practice. Results obtained from an online survey strongly confirm that hybrid development approaches are widely used in industry. Our results show that hybrid development approaches: (i) have become reality for nearly all companies; (ii) are applied to specific projects even in the presence of company-wide policies for process usage; (iii) are neither planned nor designed but emerge from the evolution of different work practices; and, (iv) are consistently used regardless of company size or industry secto
A phenomenological analysis of antiproton interactions at low energies
We present an optical potential analysis of the antiproton-proton
interactions at low energies. Our optical potential is purely phenomenological,
and has been parametrized on data recently obtained by the Obelix Collaboration
at momenta below 180 MeV/c. It reasonably fits annihilation and elastic data
below 600 MeV/c, and allows us for an evaluation of the elastic cross section
and rho-parameter down to zero kinetic energy. Moreover we show that the
mechanism that depresses antiproton-nucleus annihilation cross sections at low
energies is present in antiproton-proton interactions too.Comment: 10 pages, 4 figure
Data reduction in statistical inference
Abstract: Generalized definitions of the invariance, (partial) sufficiency and ancillarity principles are given in a measure-theoretic context. Data reduction in statistical inference is described in terms of these pril'.ciples
Influence of flock treatment with the antibiotic tylosin on poultry meat quality: results of a preliminary experiment
The veterinary antibiotic tylosin was administered to broilers at sub-therapeutic and therapeutic levels to study its effect on the quality of poultry breast meat. No statistically significant differences were observed in moisture content, pH, drip loss, colour and extent of lipid oxidation between the breast meat from treated and not treated birds. However, the cooking loss of the meat from the birds administered tylosin was significantly higher than that from the not treated ones. Additionally, the mean shear force of the breast meat was significantly lower for the sub-therapeutically treated broilers than for the not treated and the therapeutically treated ones. It was concluded that the level at which tylosin was administered to the broilers affected the quality of the breast meat, particularly its textural properties
NatCSNN: A Convolutional Spiking Neural Network for recognition of objects extracted from natural images
Biological image processing is performed by complex neural networks composed
of thousands of neurons interconnected via thousands of synapses, some of which
are excitatory and others inhibitory. Spiking neural models are distinguished
from classical neurons by being biological plausible and exhibiting the same
dynamics as those observed in biological neurons. This paper proposes a Natural
Convolutional Neural Network (NatCSNN) which is a 3-layer bio-inspired
Convolutional Spiking Neural Network (CSNN), for classifying objects extracted
from natural images. A two-stage training algorithm is proposed using
unsupervised Spike Timing Dependent Plasticity (STDP) learning (phase 1) and
ReSuMe supervised learning (phase 2). The NatCSNN was trained and tested on the
CIFAR-10 dataset and achieved an average testing accuracy of 84.7% which is an
improvement over the 2-layer neural networks previously applied to this
dataset.Comment: 12 page
The Compact Linear ee Collider (CLIC): Accelerator and Detector
The Compact Linear Collider (CLIC) is a TeV-scale high-luminosity linear
ee collider under development by international collaborations hosted by
CERN. This document provides an overview of the design, technology, and
implementation aspects of the CLIC accelerator and the detector. For an optimal
exploitation of its physics potential, CLIC is foreseen to be built and
operated in stages, at centre-of-mass energies of 380 GeV, 1.5 TeV and 3 TeV,
for a site length ranging between 11 km and 50 km. CLIC uses a two-beam
acceleration scheme, in which normal-conducting high-gradient 12 GHz
accelerating structures are powered via a high-current drive beam. For the
first stage, an alternative with X-band klystron powering is also considered.
CLIC accelerator optimisation, technical developments, and system tests have
resulted in significant progress in recent years. Moreover, this has led to an
increased energy efficiency and reduced power consumption of around 170 MW for
the 380 GeV stage, together with a reduced cost estimate of approximately 6
billion CHF. The detector concept, which matches the physics performance
requirements and the CLIC experimental conditions, has been refined using
improved software tools for simulation and reconstruction. Significant progress
has been made on detector technology developments for the tracking and
calorimetry systems. The construction of the first CLIC energy stage could
start as early as 2026 and first beams would be available by 2035, marking the
beginning of a physics programme spanning 25-30 years and providing excellent
sensitivity to Beyond Standard Model physics, through direct searches and via a
broad set of precision measurements of Standard Model processes, particularly
in the Higgs and top-quark sectors.Comment: Input to the European Particle Physics Strategy Update on behalf of
the CLIC and CLICdp Collaboration
Soluble Triggering Receptor Expressed on Myeloid cells-1 in bronchoalveolar lavage fluid is not predictive for ventilator-associated pneumonia
Kalman filter tracking and vertexing in a silicon detector for neutrino physics
This article describes the application of Kalman filter techniques for the tracking and vertexing of particles inside the NOMAD-STAR detector a silicon vertex detector installed in NOMAD, one of the neutrino oscillation experiments at the CERN-SPS. The use of the Kalman filter simplifies computationally the tracking and vertex procedure for NOMAD-STAR. The alignment of NOMAD-STAR is shown as an example of the application of the Kalman filter for tracking purposes. The accuracy of the method is such that one obtains alignment residuals between 9 and 12~m. Furthermore, a preliminary measure of the impact parameter (with an RMS m) illustrates the vertexing capabilities of this technique
- …