Search results for "Física"
showing 10 items of 4992 documents
Search for new physics in single-top-quark production with the ATLAS detector at the LHC
2018
Esta tesis presenta dos análisis dedicados a la búsqueda de nueva física en eventos de producción de quarks top únicos con datos recopilados por el detector ATLAS en el LHC. A pesar de su gran éxito, se cree que debe haber una teoría más general que subyace al Modelo Estándar de física de partículas que arroge luz a preguntas sin respuesta, como la asimetría de materia-antimateria del universo o la existencia de la Materia Oscura. Esta tesis cubre dos enfoques diferentes para abordar los dos temas anteriores. El objetivo del primer análisis es explorar la estructura del vértice Wtb a través de la medición de asimetrías angulares relacionadas con los observables de polarización del bosón W q…
Determination of the effective permittivity of dielectric mixtures with the transmission line matrix methodDetermination of the effective permittivit…
2007
In this article, the effective permittivity of two-phase dielectric mixtures is calculated by applying the transmission line matrix (TLM) method. Two slightly different TLM algorithms are considered: a hybrid approach, which combines the TLM method with a subgriding technique based on dual capacitor circuits, to allow a refined description of the material, and a standard or pure TLM approach, which uses a mesh size smaller than the typical dimension of insertions in order to appropriately describe details of the geometry. A study of the statistical distribution of permittivity for insertions in random positions is also presented, showing that the effective permittivity of the mixture tends …
Measurement of top-quark polarisation observables and a search for dark matter in single-top-quark production with the ATLAS detector at the LHC
2022
Esta tesis presenta dos análisis diferentes basados en los datos resultantes de colisiones protón-protón a una energía en el centro de masas de 13 TeV recolectados con el detector ATLAS del LHC, correspondientes a una luminosidad integrada de 139 fb$^{-1}$. El primer análisis presenta una medida de secciones eficaces diferenciales normalizadas del canal de producción de quarks top en solitario $t$-channel, donde el quark top se desintegra leptónicamente, como función de los tres ángulos de polarización del leptón para eventos con quarks top y quarks antitop tanto separadamente como de forma inclusiva. Estos observables son particularmente sensibles a efectos de nueva física en el vértice $t…
Tau decays to pions
1990
Semileptonic τ decays to two and three pions are considered. Based on recent data for the pion form factor a new prediction for Γ(τ→vπ-0)/Γ(τ→veve) of 1.32±0.05 is derived. The chiral model-supplemented by vector dominance-is used to predict rate and differential distributions for the three pion mode in good agreement with present data. The parity violating asymmetry which has been predicted theoretically and observed experimentally is studied and found to be fairly insensitive towards the details of the model for the hadronic decays.
Neutrino physics from cosmological observables and oscillation experiments
2018
Aquesta tesi se centra en la física dels neutrins. En particular, se centra en l'estudi de les oscil·lacions de sabor, el paper dels neutrins relíquia en alguns escenaris cosmològics i la interacció entre aquests dos temes. Els neutrins es troben entre les partícules elementals més conegudes. Presenten comportaments interessants, com les seves oscil·lacions, i constitueixen un dels vincles entre les diferents àrees de la física. A través d'aquest document explotem la seva relació amb la cosmologia, amb especial èmfasi en l'Univers primerenc, encara que també parlem de projectes relacionats amb les últimes etapes de la història de l'Univers. En la primera part de la tesi presentem un ajustam…
Experiments and phenomenology of electric dipole moments
2022
The Standard Model (SM) is the best description of fundamental particles and their interactions we have to date. From this theory, all phenomena in the macroscopic world (except for gravity) can be explained, and it has successfully predicted all outcomes of particle experiments on Earth. However, cosmological observations of the early Universe yield a large imbalance between its content of matter and antimatter, which is several orders of magnitude above the SM prediction. To explain these observations, new interactions that do not respect the charge-parity symmetry must exist beyond the SM. Such interactions would induce electric dipole moments (EDMs) in known particles. In Part I of the …
Study of production and cold nuclear matter effects in pPb collisions at=5 TeV
2014
Production of mesons in proton-lead collisions at a nucleon-nucleon centre-of-mass energy = 5 TeV is studied with the LHCb detector. The analysis is based on a data sample corresponding to an integrated luminosity of 1.6 nb(-1). The mesons of transverse momenta up to 15 GeV/c are reconstructed in the dimuon decay mode. The rapidity coverage in the centre-of-mass system is 1.5 < y < 4.0 (forward region) and -5.0 < y < -2.5 (backward region). The forward-backward production ratio and the nuclear modification factor for (1S) mesons are determined. The data are compatible with the predictions for a suppression of (1S) production with respect to proton-proton collisions in the forward region, an…
Innovación educativa en la educación superior a través de la blogosfera educativa
2020
INTRODUCCIÓN. En este trabajo se presenta una experiencia de uso de blogs como red de aprendizaje o blogosfera educativa, para el próximo curso escolar 2020-2021, y que forma parte del proyecto de innovación educativa Edublogs y aprendizaje colaborativo: fomentando procesos de tutorización y acompañamiento al alumnado para la mejora del aprendizaje autónomo y la evaluación, financiado por la Universitat de València. En este contexto, el profesorado responsable de la asignatura Didáctica de los Juegos y de las Actividades deportivas, de la mención de Educación Física, del Grado de Maestro/a en Educación Primaria diseñaron el blog docente, cuya principal función será conformar una red de apre…
Measurement of D*(+/-) meson production in jets from pp collisions at root s=7 TeV with the ATLAS detector
2012
This paper reports a measurement of D*(+/-) meson production in jets from proton- proton collisions at a center- of- mass energy of root s = 7 TeV at the CERN Large Hadron Collider. The measurement is based on a data sample recorded with the ATLAS detector with an integrated luminosity of 0.30 pb(-1) for jets with transverse momentum between 25 and 70 GeV in the pseudorapidity range vertical bar eta vertical bar D-0 pi(+), D-0 -> K-pi(+), and its charge conjugate. The production rate is found to be N(D*(+/-))/N(jet) = 0.025 +/- 0.001(stat.) +/- 0.004(syst.) for D*(+/-) mesons that carry a fraction z of the jet momentum in the range 0.3< z< 1. Monte Carlo predictions fail to describe the dat…
S-11-N(1535) and -N(1650) resonances in meson-baryon unitarized coupled channel chiral perturbation theory
2001
The s-wave meson-baryon scattering is analyzed for the strangeness S = 0 sector in a Bethe-Salpeter coupled channel formalism incorporating chiral symmetry. Four channels have been considered: piN, etaN, K Lambda, K Sigma. The needed two-particle irreducible matrix amplitude is taken from lowest order chiral perturbation theory in a relativistic formalism and low energy constants are fitted to the elastic piN phase shifts and the pi (-) p-->etan and pi (-) p-->K-0 Lambda cross section data. The position of the complex poles in the second Riemann sheet of the scattering amplitude determines masses and widths of the S-11-N(1535) and -N(1650) resonances, in reasonable agreement with experiment…