Spin Structure of the Pion in a Light-Cone Representation

The spin structure of the pion is discussed by transforming the wave function for the pion in the naive quark model into a light-cone representation. It is shown that there are higher helicity ($\lambda_{1}+\lambda_{2}=\pm1$) states in the full light-cone wave function for the pion besides the ordinary helicity ($\lambda_{1}+\lambda_{2}=0$) component wave functions as a consequence from the Melosh rotation relating spin states in light-front dynamics and those in instant-form dynamics. Some low energy properties of the pion, such as the electromagnetic form factor, the charged mean square radius, and the weak decay constant, could be interrelated in this representation with reasonable parameters.Comment: 15 Latex pages, 2 figures upon reques

Field test of available methods to measure remotely SO2 and NOx emissions from ships

Methods for the determination of ship fuel sulphur content and NOx emission factors based on remote measurements have been compared in the harbour of Rotterdam and compared to direct stack emission measurements on the ferry Stena Hollandica. The methods were selected based on a review of the available literature on ship emission measurements. They were either optical (LIDAR, DOAS, UV camera), combined with model based estimates of fuel consumption, or based on the so called ‘sniffer’ principle, where SO2 or NOx emission factors are determined from simultaneous measurement of the increase of CO2 and SO2 or NOx concentrations in the plume of the ship compared to the background. The measurements were performed from stations at land, from a boat and from a helicopter. Mobile measurement platforms were found to have important advantages compared to the landbased ones because they allow to optimize the sampling conditions and to sample from ships on the open sea. Although optical methods can provide reliable results it was found that at the state of the art, the “sniffer” approach is the most convenient technique for determining both SO2 and NOx emission factors remotely. The average random error on the determination of SO2 emission factors comparing two identical instrumental set-ups was 6%. However, it was found that apparently minor differences in the instrumental characteristics, such as response time, could cause significant differences between the emission factors determined. Direct stack measurements showed that about 14% of the fuel sulphur content was not emitted as SO2. This was supported by the remote measurements and is in agreement with the results of other field studies.JRC.H.2-Air and Climat

A study of charged kappa in J/ψ→K±Ksπ∓π0J/\psi \to K^{\pm} K_s \pi^{\mp} \pi^0

Based on $58 \times 10^6$ $J/\psi$ events collected by BESII, the decay $J/\psi \to K^{\pm} K_s \pi^{\mp} \pi^0$ is studied. In the invariant mass spectrum recoiling against the charged $K^*(892)^{\pm}$, the charged $\kappa$ particle is found as a low mass enhancement. If a Breit-Wigner function of constant width is used to parameterize the kappa, its pole locates at $(849 \pm 77 ^{+18}_{-14}) -i (256 \pm 40 ^{+46}_{-22})$ MeV/$c^2$. Also in this channel, the decay $J/\psi \to K^*(892)^+ K^*(892)^-$ is observed for the first time. Its branching ratio is $(1.00 \pm 0.19 ^{+0.11}_{-0.32}) \times 10^{-3}$.Comment: 14 pages, 4 figure

Magnetic Field Amplification in Galaxy Clusters and its Simulation

We review the present theoretical and numerical understanding of magnetic field amplification in cosmic large-scale structure, on length scales of galaxy clusters and beyond. Structure formation drives compression and turbulence, which amplify tiny magnetic seed fields to the microGauss values that are observed in the intracluster medium. This process is intimately connected to the properties of turbulence and the microphysics of the intra-cluster medium. Additional roles are played by merger induced shocks that sweep through the intra-cluster medium and motions induced by sloshing cool cores. The accurate simulation of magnetic field amplification in clusters still poses a serious challenge for simulations of cosmological structure formation. We review the current literature on cosmological simulations that include magnetic fields and outline theoretical as well as numerical challenges.Comment: 60 pages, 19 Figure

Covariant description of inelastic electron--deuteron scattering:predictions of the relativistic impulse approximation

Using the covariant spectator theory and the transversity formalism, the unpolarized, coincidence cross section for deuteron electrodisintegration, $d(e,e'p)n$, is studied. The relativistic kinematics are reviewed, and simple theoretical formulae for the relativistic impulse approximation (RIA) are derived and discussed. Numerical predictions for the scattering in the high $Q^2$ region obtained from the RIA and five other approximations are presented and compared. We conclude that measurements of the unpolarized coincidence cross section and the asymmetry $A_\phi$, to an accuracy that will distinguish between different theoretical models, is feasible over most of the wide kinematic range accessible at Jefferson Lab.Comment: 54 pages and 24 figure

MICROALGAS: POTENCIAL PARA A PRODUÇÃO DE COMPOSTOS BIOATIVOS NANOENCAPSULADOS

Las microalgas se presentan como una fuente potencial de compuestos bioactivos para ser utilizado en la industria alimentaria generando alimentos funcionales. El desarrollo y búsqueda de alimentos funcionales, como método para mejorar y mantener la salud representa un campo de la investigación muy explorado en años recientes. Lípidos, proteínas, polisacáridos, compuestos fenólicos, carotenoides, entre otros bioproductos proveniente de microalgas pueden ser utilizados como fuente de ingredientes para productos funcionales, sin embargo, la inestabilidad química de muchos de ellos puede comprometer su acción. La nanoencapsulación representa una herramienta nanotecnológica capaz de proporcionar mejoras en la estabilidad y actividad biológica de los compuestos bioactivos provenientes de microalgas. Esta revisión persigue mostrar la importancia, mejoras y potencialidad en la elaboración de compuestos bioactivos de microalgas para productos nanoencapsulados con utilidad en la industria de alimentos.As microalgas se apresentam como uma fonte potencial de compostos bioativos para utilização na indústria alimentícia, produzindo alimentos funcionais. O desenvolvimento e procura de alimentos funcionais, como método para melhorar e manter a saúde representa uma área substancialmente explorada nos últimos anos. Lipídeos, proteínas, polissacarídeos, compostos fenólicos, carotenóides, entre outros bioprodutos das microalgas podem ser utilizados como ingredientes para produtos funcionais, mas, a instabilidade química de muitos deles pode comprometer sua ação. A nanoencapsulação é uma ferramenta nanotecnológica capaz de proporcionar melhorias de estabilidade e atividade biológica dos compostos bioativos derivados de microalgas. Esta revisão procura mostrar a importância, melhoria e potencialidade na elaboração de compostos bioativos das microalgas para produtos nanoencapsulados com potencial para a indústria de alimentos

Search for black holes and other new phenomena in high-multiplicity final states in proton-proton collisions at root s=13 TeV

Peer reviewe

The evolution of language: a comparative review

For many years the evolution of language has been seen as a disreputable topic, mired in fanciful "just so stories" about language origins. However, in the last decade a new synthesis of modern linguistics, cognitive neuroscience and neo-Darwinian evolutionary theory has begun to make important contributions to our understanding of the biology and evolution of language. I review some of this recent progress, focusing on the value of the comparative method, which uses data from animal species to draw inferences about language evolution. Discussing speech first, I show how data concerning a wide variety of species, from monkeys to birds, can increase our understanding of the anatomical and neural mechanisms underlying human spoken language, and how bird and whale song provide insights into the ultimate evolutionary function of language. I discuss the ‘‘descended larynx’ ’ of humans, a peculiar adaptation for speech that has received much attention in the past, which despite earlier claims is not uniquely human. Then I will turn to the neural mechanisms underlying spoken language, pointing out the difficulties animals apparently experience in perceiving hierarchical structure in sounds, and stressing the importance of vocal imitation in the evolution of a spoken language. Turning to ultimate function, I suggest that communication among kin (especially between parents and offspring) played a crucial but neglected role in driving language evolution. Finally, I briefly discuss phylogeny, discussing hypotheses that offer plausible routes to human language from a non-linguistic chimp-like ancestor. I conclude that comparative data from living animals will be key to developing a richer, more interdisciplinary understanding of our most distinctively human trait: language

Search for heavy resonances decaying into a vector boson and a Higgs boson in final states with charged leptons, neutrinos, and b quarks

Peer reviewe

Search for high-mass diphoton resonances in proton-proton collisions at 13 TeV and combination with 8 TeV search

Peer reviewe