10,919 research outputs found
Impact of the inelastic proton -- nucleus cross section on the prompt neutrino flux
The description of the inelastic proton -- nucleus cross section at very high
energies is still an open question. The current theoretical uncertainty has
direct impact on the predictions of the cosmic ray and neutrino physics
observables. In this paper we consider different models for the treatment of
, compare its predictions at ultrahigh cosmic ray energies
and estimate the prompt neutrino flux at the neutrino energies that have been
probed by the IceCube Observatory. We demonstrate that depending of the model
used to describe , the predictions for the prompt neutrino
flux can differ by a factor of order of three. Such result demonstrate the
importance of a precise measurement of the inelastic proton -- nucleus cross
section at high energies.Comment: 5 pages, 3 figures; v2: corrected the range of horizontal axis in
figure 1. Matches the version published in Eur. Phys. J.
An approach to harmonic load- and source-pull measurements for high-efficiency PA design
High-efficiency power-amplifier design requires numerous efforts to investigate both input and output harmonic terminations effects. A simplified theoretical approach to clarify the relevance of such terminations is presented here, and design criteria to improve efficiency for high-frequency applications are briefly discussed. An advanced active load/source-pull test-bench has been used to validate theoretical harmonic tuning techniques, characterizing an active device. The adopted optimization strategy is presented, together with measured results obtained with a medium-power 1-mm MESFET at 1 GHz. Input second harmonic impedances effects are stressed, showing a drain efficiency spread between 37%-49% for a fixed input power level, corresponding to 1-dB compression. Finally, as predicted by the presented theory, after input second harmonic tuning, further improvements are obtained, increasing fundamental output load resistive part, demonstrating an additional drain efficiency enhancement, which reaches a level of 55% at 1-dB compression
Quantum Plasmonics
Quantum plasmonics is an exciting subbranch of nanoplasmonics where the laws of quantum theory are used to describe lightâmatter interactions on the nanoscale. Plasmonic materials allow extreme subdiffraction confinement of (quantum or classical) light to regions so small that the quantization of both light and matter may be necessary for an accurate description. State-of-the-art experiments now allow us to probe these regimes and push existing theories to the limits which opens up the possibilities of exploring the nature of many-body collective oscillations as well as developing new plasmonic devices, which use the particle quality of light and the wave quality of matter, and have a wealth of potential applications in sensing, lasing, and quantum computing. This merging of fundamental condensed matter theory with application-rich electromagnetism (and a splash of quantum optics thrown in) gives rise to a fascinating area of modern physics that is still very much in its infancy. In this review, we discuss and compare the key models and experiments used to explore how the quantum nature of electrons impacts plasmonics in the context of quantum size corrections of localized plasmons and quantum tunneling between nanoparticle dimers. We also look at some of the remarkable experiments that are revealing the quantum nature of surface plasmon polaritons
Neural-Based Nonlinear Device Models for Intermodulation Analysis
A new procedure to learn a nonlinear model together with its derivative parameters using a composite neural network is presented.So far neural networks have never been used to extract large-signal device model accounting for distortion parameters.Applying this method to FET devices leads to nonlinear models for current- voltage functions which allow improved prediction of weak and mildly device nonlinearities in the whole bias region. The resulting models have demonstrated to be suitable for both small-signal and large-signal analyses,including intermodulation distortion prediction
On the rapidity dependence of the average transverse momentum in hadronic collisions
The energy and rapidity dependence of the average transverse momentum
in and collisions at RHIC and LHC energies are
estimated using the Colour Glass Condensate (CGC) formalism. We update previous
predictions for the - spectra using the hybrid formalism of the CGC
approach and two phenomenological models for the dipole - target scattering
amplitude. We demonstrate that these models are able to describe the RHIC and
LHC data for the hadron production in , and collisions at GeV. Moreover, we present our predictions for and
demonstrate that the ratio decreases with the rapidity and has a behaviour similar to that
predicted by hydrodynamical calculations.Comment: 11 pages, 7 figures; revised version: new results for the average
transverse momentum at partonic level added in fig. 4; Results and Discussion
section has been improved and enlarge
Testing the running coupling -factorization formula for the inclusive gluon production
The inclusive gluon production at midrapidities is described in the Color
Glass Condensate formalism using the - factorization formula, which was
derived at fixed coupling constant considering the scattering of a dilute
system of partons with a dense one. Recent analysis demonstrated that this
approach provides a satisfactory description of the experimental data for the
inclusive hadron production in collisions. However, these studies
are based on the fixed coupling - factorization formula, which does not
take into account the running coupling corrections, which are important to set
the scales present in the cross section. In this paper we consider the running
coupling corrected - factorization formula conjectured some years ago and
investigate the impact of the running coupling corrections on the observables.
In particular, the pseudorapidity distributions and charged hadrons
multiplicity are calculated considering , and
collisions at RHIC and LHC energies. We compare the corrected running coupling
predictions with those obtained using the original - factorization
assuming a fixed coupling or a prescription for the inclusion of the running of
the coupling. Considering the Kharzeev - Levin - Nardi unintegrated gluon
distribution and a simplified model for the nuclear geometry, we demonstrate
that the distinct predictions are similar for the pseudorapidity distributions
in collisions and for the charged hadrons multiplicity in
collisions. On the other hand, the running coupling corrected -
factorization formula predicts a smoother energy dependence for in
collisions.Comment: 9 pages and 4 figure
Theoretical and experimental assessment of the non-linear scattering functions for the cad of non-linear microwave circuits
The Non-Linear Scattering Functions have been theoretically defined and experimentally measured for the linear-equivalent design of non-linear circuits in arbitrary large signal conditions. Non-linear measures and simulations have been compared, with good agreement. Linear CAD concepts can therefore be extended to non-linear circuits in a rigorous way
Museums and Digital Culture: New perspectives and research
This richly illustrated book offers new perspectives and research on how digital
culture is transforming museums in the 21st century, as they strive to keep pace
with emerging technologies driving cultural and social change, played out not only
in todayâs pervasive networked environment of the Internet and Web, but in
everyday life, from home to work and on city streets. In a world where digital
culture has redefined human information behavior as life in code and digits,
increasingly it dominates human activity and communication. These developments
have radically changed the expectations of the museum visitor, real and virtual, the
work of museum professionals and, most prominently, the nature of museum
exhibitions, while digital art and life in a digitally saturated world is changing our
ways of seeing, doing, our senses and aesthetics.
Overall, this book creates a new picture of the 21st-century museum field. As
museums become shared spaces with their communities, local, national and global
and move from collection-centered to user-/visitor-centered institutions, they are
assuming new roles and responsibilities tied to new goals for engaging their
audience, conveying meaning through collections, creating learning experiences
and importantly, connecting to daily digital life and culture integral to the museum
ecosystem. Our studies of recent exhibitions at museums leading change are used to
exemplify new directions, while they point to a reimagined vision for museums
of the future at the heart of which is the integration of digital culture and visitor
experience and participation in real and virtual space
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