325 research outputs found
Quantum tomography for Dirac spinors
We present a tomographic scheme, based on spacetime symmetries, for the
reconstruction of the internal degrees of freedom of a Dirac spinor. We discuss
the circumstances under which the tomographic group can be taken as SU(2), and
how this crucially depends on the choice of the gamma matrix representation. A
tomographic reconstruction process based on discrete rotations is considered,
as well as a continuous alternative.Comment: 9 pages, LaTeX; v2: minor changes, references added. A slightly
revised version has been accepted for publication in Phys. Lett.
Continuous variable entanglement and quantum state teleportation between optical and macroscopic vibrational modes through radiation pressure
We study an isolated, perfectly reflecting, mirror illuminated by an intense
laser pulse. We show that the resulting radiation pressure efficiently
entangles a mirror vibrational mode with the two reflected optical sideband
modes of the incident carrier beam. The entanglement of the resulting
three-mode state is studied in detail and it is shown to be robust against the
mirror mode temperature. We then show how this continuous variable entanglement
can be profitably used to teleport an unknown quantum state of an optical mode
onto the vibrational mode of the mirror.Comment: 18 pages, 10 figure
Removal of a single photon by adaptive absorption
We present a method to remove, using only linear optics, exactly one photon
from a field-mode. This is achieved by putting the system in contact with an
absorbing environment which is under continuous monitoring. A feedback
mechanism then decouples the system from the environment as soon as the first
photon is absorbed. We propose a possible scheme to implement this process and
provide the theoretical tools to describe it
Simbióticos e monensina sódica no desempenho e na qualidade da carne de novilhas mestiças Angus confinadas
Resumo:O objetivo deste trabalho foi avaliar o efeito da inclusĂŁo de simbiĂłticos e de monensina sĂłdica em dietas sobre o desempenho, as caracterĂsticas de carcaça e a qualidade da carne de novilhas mestiças Angus em confinamento. Utilizou-se um delineamento inteiramente casualizado, com 64 animais distribuĂdos em quatro tratamentos: controle, dieta sem suplementação; dieta suplementada com simbiĂłticos; dieta com monensina sĂłdica; e dieta com simbiĂłticos e monensina sĂłdica. A dieta com monensina sĂłdica e a dieta com simbiĂłticos e monensina sĂłdica proporcionaram maior ganho de peso mĂ©dio diĂĄrio e ganho de peso vivo total, alĂ©m de melhorar a eficiĂȘncia alimentar e biolĂłgica dos animais em comparação ao controle. A dieta de simbiĂłticos, a de monensina e a de simbiĂłticos com monensina sĂłdica ocasionaram a redução da ingestĂŁo de matĂ©ria seca, elevaram o peso do filĂ© da costela e os teores de lipĂdeos totais na carne. A dieta com simbiĂłticos proporcionou a redução da força de cisalhamento da carne em relação ao controle. A inclusĂŁo de simbiĂłticos, com ou sem monensina sĂłdica, na dieta de novilhas mestiças Angus confinadas, beneficia o desempenho animal e algumas caracterĂsticas fĂsico-quĂmicas da carne
Geographical and temporal distribution of SARS-CoV-2 clades in the WHO European Region, January to June 2020
We show the distribution of SARS-CoV-2 genetic clades over time and between countries and outline potential genomic surveillance objectives. We applied three available genomic nomenclature systems for SARS-CoV-2 to all sequence data from the WHO European Region available during the COVID-19 pandemic until 10 July 2020. We highlight the importance of real-time sequencing and data dissemination in a pandemic situation. We provide a comparison of the nomenclatures and lay a foundation for future European genomic surveillance of SARS-CoV-2.Peer reviewe
Measurement of the cross section for isolated-photon plus jet production in pp collisions at âs=13 TeV using the ATLAS detector
The dynamics of isolated-photon production in association with a jet in protonâproton collisions at a centre-of-mass energy of 13 TeV are studied with the ATLAS detector at the LHC using a dataset with an integrated luminosity of 3.2 fbâ1. Photons are required to have transverse energies above 125 GeV. Jets are identified using the anti- algorithm with radius parameter and required to have transverse momenta above 100 GeV. Measurements of isolated-photon plus jet cross sections are presented as functions of the leading-photon transverse energy, the leading-jet transverse momentum, the azimuthal angular separation between the photon and the jet, the photonâjet invariant mass and the scattering angle in the photonâjet centre-of-mass system. Tree-level plus parton-shower predictions from Sherpa and Pythia as well as next-to-leading-order QCD predictions from Jetphox and Sherpa are compared to the measurements
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