Search results for "PIO"
showing 10 items of 2238 documents
Estimating the two-particle $K$-matrix for multiple partial waves and decay channels from finite-volume energies
2017
An implementation of estimating the two-to-two $K$-matrix from finite-volume energies based on the L\"uscher formalism and involving a Hermitian matrix known as the "box matrix" is described. The method includes higher partial waves and multiple decay channels. Two fitting procedures for estimating the $K$-matrix parameters, which properly incorporate all statistical covariances, are discussed. Formulas and software for handling total spins up to $S=2$ and orbital angular momenta up to $L=6$ are obtained for total momenta in several directions. First tests involving $\rho$-meson decay to two pions include the $L=3$ and $L=5$ partial waves, and the contributions from these higher waves are f…
Compton scattering by a pion and off-shell effects
1994
We consider Compton scattering by a pion in the framework of chiral perturbation theory. We investigate off--shell effects in the s-- and u--channel pole diagrams. For that purpose we perform a field transformation which, in comparison with the standard Gasser and Leutwyler Lagrangian, generates additional terms at order $p^4$ proportional to the lowest--order equation of motion. As a result of the equivalence theorem the two Lagrangians predict the same Compton scattering S--matrix even though they generate different off--shell form factors. We conclude that off--shell effects are not only model--dependent but also representation--dependent.
Virtual Compton Scattering and Neutral Pion Electroproduction in the Resonance Region up to the Deep Inelastic Region at Backward Angles
2009
We have made the first measurements of the virtual Compton scattering (VCS) process via the H$(e,e'p)\gamma$ exclusive reaction in the nucleon resonance region, at backward angles. Results are presented for the $W$-dependence at fixed $Q^2=1$ GeV$^2$, and for the $Q^2$-dependence at fixed $W$ near 1.5 GeV. The VCS data show resonant structures in the first and second resonance regions. The observed $Q^2$-dependence is smooth. The measured ratio of H$(e,e'p)\gamma$ to H$(e,e'p)\pi^0$ cross sections emphasizes the different sensitivity of these two reactions to the various nucleon resonances. Finally, when compared to Real Compton Scattering (RCS) at high energy and large angles, our VCS data…
Elastic pion scattering on the deuteron in a multiple scattering model
1996
Pion elastic scattering on deuterium is studied in the KMT multiple scattering approach developed in momentum space. Using a Paris wave function and the same methods and approximations as commonly used in pion scattering on heavier nuclei excellent agreement with differential cross section data is obtained for a wide range of pion energies. Only for $T_{\pi}>250$ MeV and very backward angles, discrepancies appear that are reminiscent of disagreements in pion scattering on $^3$He, $^3$H, and $^4$He. At low energies the second order corrections have been included. Polarization observables are studied in detail. While tensor analyzing powers are well reproduced, vector analyzing powers exhibit…
Virtual Compton Scattering and polarizabilities
1999
Abstract Virtual Compton Scattering (VCS) off the proton below pion threshold allows access to generalized polarizabilities of the proton. These observables measure the response of the nucleon to low energy electromagnetic field perturbations. This paper presents a comparison with Real Compton Scattering and also results for the first dedicated VCS experiment performed at the Mainz Microtron MAMI with high resolution spectrometers at Q2 = 0.33 GeV2.
Przyjaciele dzieci: Filip Neri, Urszula Ledóchowska, Jan Bosko w wierszowanych opowieściach z serii "Święci uśmiechnięci" Elizy Piotrowskiej
2020
When describing the figures of saints, Eliza Piotrowska follows the order set by hagiography. However, it does not mean the reproduction of the cultural stereotype of a saint to which we have been accustomed by religious literature and folklore. We will find many images and motifs transferred from fictionalised biographies of “wondrous children.” Bearing in mind the small audience, she replaces seriousness with humour, which dominates all levels of the text. The author is not afraid to juxtapose book protagonists with contemporary children, which she also illustrates herself. She reaches for anecdotes, jokes, aphorisms, and different points of view. The author’s narrative and graphic skills…
El poder financiero de los municipios y su marco constitucional
2017
La Constitución establece un marco para el ejercicio del poder financiero por parte de los distintos entes territoriales. Los Municipios, en aplicación de preceptos de la Carta Manga, dispondrán de autonomía y suficiencia financiera (art. 140 y 152 CE). Asimismo, y en aplicación del principio de competencia, los Entes Locales podrán desarrollar su potestad reglamentaria en las materias que le sean propias. Por todo ello, el presente trabajo tiene por objeto el análisis y valoración de la aplicación y eficacia que despliegan estos principios constitucionales en el ejercicio del poder financiero municipal y sus límites cuando confluyan con otras Administraciones The Constitution establishes a…
Una lettura sociologica delle emozioni e della sessualità
2018
All’ interno del capitolo, dopo aver indicato le relazioni assai recenti tra teorizzazione sociologica contemporanea e sessualità umana, cercheremo di comprendere in che modo le emozioni possano essere considerate prodotti intrinsecamente sociali, riflettendo – per concludere – sul rapporto tra costruzione delle emozioni e processi di socializzazione di genere e sessuale.
Cuando secretos de Estado y espionaje chocan contra los derechos fundamentales
2022
Caso sobre el uso del programa espía Pegasus. Control servicios de inteligencia. Derechos fundamentales y secreto de Estado