Fingerprints of heavy scales in electroweak effective Lagrangians

The couplings of the electroweak effective theory contain information on the heavy-mass scales which are no-longer present in the low-energy Lagrangian. We build a general effective Lagrangian, implementing the electroweak chiral symmetry breaking $SU(2)_L\otimes SU(2)_R\to SU(2)_{L+R}$, which couples the known particle fields to heavier states with bosonic quantum numbers $J^P=0^\pm$ and $1^\pm$. We consider colour-singlet heavy fields that are in singlet or triplet representations of the electroweak group. Integrating out these heavy scales, we analyze the pattern of low-energy couplings among the light fields which are generated by the massive states. We adopt a generic non-linear realization of the electroweak symmetry breaking with a singlet Higgs, without making any assumption about its possible doublet structure. Special attention is given to the different possible descriptions of massive spin-1 fields and the differences arising from naive implementations of these formalisms, showing their full equivalence once a proper short-distance behaviour is required.Comment: 57 pages, 1 pdf figure. Version published at JHE

A few words about Resonances in the Electroweak Effective Lagrangian

Contrary to a widely spread believe, we have demonstrated that strongly coupled electroweak models including both a light Higgs-like boson and massive spin-1 resonances are not in conflict with experimental constraints on the oblique S and T parameters. We use an effective Lagrangian implementing the chiral symmetry breaking SU(2)_L x SU(2)_R -> SU(2)_{L+R} that contains the Standard Model gauge bosons coupled to the electroweak Goldstones, one Higgs-like scalar state h with mass m_h=126 GeV and the lightest vector and axial-vector resonance multiplets V and A. We have considered the one-loop calculation of S and T in order to study the viability of these strongly-coupled scenarios, being short-distance constraints and dispersive relations the main ingredients of the calculation. Once we have constrained the resonance parameters, we do a first approach to the determination of the low energy constants of the electroweak effective theory at low energies (without resonances). We show this determination in the case of the purely Higgsless bosonic Lagrangian.Comment: 6 pages, 2 figures. Talk given at XIth Quark Confinement and Hadron Spectrum, 8-12th September (2014), Saint Petersburg (Russia

An ecofeminist critical discourse analysis

The present paper examines ideological persuasion in discourses and reflects the importance of linguistics for society. By following a Critical Discourse Analysis, the aim of this study is to analyze a persuasive discourse whose linguistic mechanisms lead to the transmission of an ecofeminist ideology. This movement is indeed grounded in the existing relation between domination over women and nature (Gaard 1), conceiving the fight against patriarchy as a suitable solution (Warren, Ecofeminist Philosophy 64). In order to achieve this socio-linguistic connection, the discourse under study is delivered by a victim of patriarchy, Malala Yousafzai, who overtly claims educational equity before the United Nations Youth Takeover in 2013. The analysis is based on Fairclough’s approach to CDA (57), where he states that meaning in discourses arises from the combination of the text, its discourse practice and socio-cultural practice.El presente trabajo estudia la persuasión ideológica de los discursos y refleja la importancia de la lingüística para la sociedad. Siguiendo un Análisis Crítico del Discurso, el objetivo de este estudio es analizar un discurso persuasivo cuyos mecanismos lingüísticos propicien la transmisión de una ideología ecofeminista. De hecho, este movimiento se fundamenta en la relación existente entre la dominación sobre las mujeres y la naturaleza (Gaard 1), y contempla la lucha contra el patriarcado como una solución viable (Warren, Ecofeminist Philosophy 64). Para lograr esta conexión socio-lingüística, el discurso a estudiar se pronuncia por una víctima del patriarcado, Malala Yousafzai, que reivindica abiertamente la igualdad educativa frente a un foro juvenil de la ONU en 2013.Departamento de Filología InglesaGrado en Estudios Inglese

Multiwavelength observations of a bright impact flash during the January 2019 total lunar eclipse

We discuss here a lunar impact flash recorded during the total lunar eclipse that occurred on 2019 January 21, at 4h 41m 38.09 +- 0.01 s UT. This is the first time ever that an impact flash is unambiguously recorded during a lunar eclipse and discussed in the scientific literature, and the first time that lunar impact flash observations in more than two wavelengths are reported. The impact event was observed by different instruments in the framework of the MIDAS survey. It was also spotted by casual observers that were taking images of the eclipse. The flash lasted 0.28 seconds and its peak luminosity in visible band was equivalent to the brightness of a mag. 4.2 star. The projectile hit the Moon at the coordinates 29.2 +- 0.3 $^{\circ}$S, 67.5 +- 0.4 $^{\circ}$W. In this work we have investigated the most likely source of the projectile, and the diameter of the new crater generated by the collision has been calculated. In addition, the temperature of the lunar impact flash is derived from the multiwavelength observations. These indicate that the blackbody temperature of this flash was of about 5700 K.Comment: Accepted for publication in MNRAS on 2019 March 2

Colorful Imprints of Heavy States in the Electroweak Effective Theory

We analyze heavy states from generic ultraviolet completions of the Standard Model in a model-independent way and investigate their implications on the low-energy couplings of the electroweak effective theory. We build a general effective Lagrangian, implementing the electroweak symmetry breaking $SU(2)_L\otimes SU(2)_R\to SU(2)_{L+R}$ with a non-linear Nambu-Goldstone realization, which couples the known particles to the heavy states. We generalize the formalism developed in previous works~[1,2] to include colored resonances, both of bosonic and fermionic type. We study bosonic heavy states with $J^P=0^\pm$ and $J^P=1^\pm$, in singlet or triplet $SU(2)_{L+R}$ representations and in singlet or octet representations of $SU(3)_C$, and fermionic resonances with $J=\frac{1}{2}$ that are electroweak doublets and QCD triplets or singlets. Integrating out the heavy scales, we determine the complete pattern of low-energy couplings at the lowest non-trivial order. Some specific types of (strongly- and weakly-coupled) ultraviolet completions are discussed to illustrate the generality of our approach and to make contact with current experimental searches.Comment: 51 pages, 2 figures, 12 tables; v2: matches Journal versio

Angelina Muñiz, novelista de la generación hispanomexicana.

Sin resume