Ωc\Omega_c excited states: a molecular approach with heavy-quark spin symmetry

The LHCb Collaboration has recently discovered five excited $\Omega_c$ states with masses between 3 and 3.1 GeV, four of them corroborated by the Belle Collaboration. We analyse the dynamical generation of these states within a molecular baryon-meson model that is consistent with both chiral and heavy-quark spin symmetries. Earlier predictions within this model found five $\Omega_c$ states with masses below 3 GeV. Thus, in order to study the possible identification of any of these states with the experimental ones in the correct energy region, we explore two different regularization schemes, that is, a modified regularization subtraction method and a cutoff regularization scheme. We find that at least three of the dynamically generated states can be identified with the experimental ones and have spin-parity $J=1/2^-$ or $J=3/2^-$Comment: 6 pages, 3 tables, 1 figure, contribution based on a keynote parallel talk of the 8th International Conference on Quarks and Nuclear Physics (QNP2018), November 13-17, 2018, Tsukuba (Japan

Dynamics of charmed and bottomed meson and baryon resonances

En la actualidad, el Modelo Estándar es el mejor marco teórico de que disponemos para describir multitud de fenómenos de física de partículas. Dentro del mismo, la Cromodinámica Cuántica (QCD) es la teoría que describe la interacción fuerte entre quarks y gluones, de los que están compuestos los hadrones. En este trabajo estudiamos diversos procesos hadrónicos donde se involucran bajas transferencias de energías y momentos. Al contrario que en otras teorías del Modelo Estándar, en este régimen, la aproximación perturbativa para QCD no resulta adecuada, porque la intensidad de la interacción fuerte aumenta al disminuir las escalas energéticas relevantes ( q), dando lugar a la propiedad de confinamiento para q ≤ ΛQCD ∼ 200 − 250 MeV. En la práctica, es necesario resolver no perturbativamente QCD utilizando técnicas Monte Carlo en un espacio-tiempo discretizado (lattice QCD), o formular teorías efectivas, que son aproximaciones de la teoría subyacente (QCD) basadas en ciertas de sus simetrías, exactas o aproximadas. En esta tesis describimos la dinámica de algunas resonancias, que interpretamos como moléculas, producto de la interacción entre dos hadrones. Para ello utilizamos una combinación de teorías efectivas y resumaciones no perturbativas. El trabajo se estructura en cuatro partes. En la Parte I se presenta el forma- lismo físico-matemático necesario para obtener y analizar los resultados del resto de la tesis. Empezamos con un primer capítulo introductorio muy generico. A conti- nuación, en el Capítulo 2 se describen brevemente QCD y la teoría quiral de per- turbaciones (χPT ), la teoría efectiva que describe las interacciones entre bosones de Goldstone y de estos mesones con otras partículas (mesones vectoriales y bariones ligeros o hadrones con un quark pesado), también estudiadas en esta memoria. En este mismo capítulo se discute el formalismo del local hidden gauge (LHG), que pro- pone una extensión de χ PT para incluir las interacciones de los mesones vectoriales, y finalmente la simetría de espín de quarks pesados (HQSS). En este último caso, se presta una atención especial a las simplificaciones que se deducen, en el límite de masa de quark infinita, para la evaluación de elementos de matriz de transiciones que involucran estados iniciales y finales con hadrones pesados. En el Capítulo 3, se presenta una breve introducción a la teoría de dispersión de dos cuerpos, a los v conceptos de unitariedad, analiticidad, y a la definición de las hojas de Riemann de la amplitud extendida al plano complejo. A continuación, se extiende el formalismo para estudiar canales acoplados y presentamos el esquema quiral unitario (CUA), donde se restaura unitariedad en las amplitudes quirales del Capítulo 3 utilizando la ecuación de Bethe-Salpeter (BSE) . Por último, utilizando los conceptos de uni- tariedad y analiticidad, en la última sección se detallan las condiciones para las que los loops con topología triangular, que pueden dar lugar a singularidades en el plano complejo de la matriz T , produzcan efectos visibles en los espectros experimentales. En las Partes II, III y IV se presentan los resultados de esta tesis, todos publicados en revistas internacionales del primer tercil especializadas en física hadrónica. En la Parte II, abordamos diversos procesos en el sector ligero em- pleando las técnicas y los modelos presentados en la Parte I. En la Parte III estudiamos varias resonancias bariónicas en el los sctores de Charm y Bottom, utilizando las técnicas detalladas en las Partes I y II, debidamente extendidas al sector pesado. En la Parte IV estudiamos el efecto de las singularidades triangulares, haciendo uso de las técnicas presentadas y desarrolladas a lo largo de esta tesis, en varias reacciones que involucran hadrones ligeros y pesados. Finalmente, en la Parte V se resumen los resultados principales y conclusiones de esta tesis.Particle Physics is currently best described by the Standard Model. Within this framework, the interaction between quarks and gluons is characterized by the theory of Quantum Chromodynamics (QCD). Hadrons can be formed by combining quarks and gluons through strong interaction. However, these interactions happen typically at low energies and, unlike the other theories in the Standard Model, QCD can be only calculated perturbatively at high energies. As a consequence, to describe this non-perturbative regime one has to apply other approaches, like lattice QCD (LQCD), scattering theory, effective theories... In this thesis, special attention will be given to molecular resonances that result from the interaction between two hadrons, which will be described using a combination of non-perturbative resummations and effective theories. In particular we will focus on resonances containing one heavy quark. The thesis is divided into four parts. Part I deals with the mathematical and physical formalism necessary to understand the results. We briefly present begin with chiral perturbation theory ($\chi$PT), local hidden gauge (LHG) formalism and heavy quark spin symmetry (HQSS). Furthermore, we review the concepts of analyticity, unitarity and Riemann sheets of scattering amplitudes and we explain under which conditions triangle loops can give rise to singularities that can be experimentally observed. In Parts II, III and IV we present the results of this dissertation, that were obtained using the techniques outlined previously. In Part II, the behavior of hadrons in the light sector is explored, using the techniques and models presented in the previous chapters, such as the CUA in coupled channels and the study of dynamically generated resonances. In Part III, baryon resonance states with heavy quarks, such as the $\Lambda_{c (b)}^{(*)}, \ \Omega_c^{(*)}$ and $\Xi_{c (b)}^{(*)}$, are studied using the various techniques presented in Parts I and II. In Part~IV we study the effect of triangle singularities in several reactions involving both light and heavy hadrons, making use also of the techniques explored and developed so far in this thesis. Finally, in Part V, a summary of the main results and conclusions obtained in this thesis is given

The negative-parity spin-1/2 Λ\Lambda baryon spectrum from lattice QCD and effective theory

The spectrum of the negative-parity spin-1/2 $\Lambda$ baryons is studied using lattice QCD and hadronic effective theory in a unitarized coupled-channel framework. A direct comparison between the two approaches is possible by considering the hadronic effective theory in a finite volume and with hadron masses and mesonic decay constants that correspond to the situation studied on the lattice. Comparing the energy level spectrum and $SU(3)$ flavor decompositions of the individual states, it is found that the lowest two states extracted from lattice QCD can be identified with one of the two $\Lambda(1405)$-poles and the $\Lambda(1670)$ resonance. The quark mass dependences of these two lattice QCD levels are in good agreement with their effective theory counterparts. However, as current lattice QCD studies still rely on three-quark operators to generate the physical states, clear signals corresponding to the meson-baryon scattering states, that appear in the finite volume effective theory calculation, are not yet seen.Comment: 10 pages, 6 figure

Doenças endocrinológicas com repercussões psiquiátricas: revisão sistemática / Endocrinological disorders with psychiatric repercussions: a systematic review

O objetivo do estudo foi realizar uma revisão sistemática de literatura sobre doenças endocrinológicas com repercussões psiquiátricas. Para isso, realizou-se uma revisão sistemática de literatura, através de uma busca nas bases de dados Latino-Americana e do Caribe em Ciências da Saúde, Google Scholar e Scientific Electronic Library Online, utilizando-se os descritores: Endocrinology, Mental Disorders, Psychiatric Symptoms, Cushing’s syndrome, Hyperthyroidism, Hypothyroidism, Addison disease. Através disso, foram selecionados 12 artigos que compunham os critérios de inclusão e exclusão do presente estudo. Dessa forma, destaca-se que os estudos evidenciaram que diversos são as repercussões psiquiátricas em pacientes com doenças endocrinológicas, variando desde transtornos de ansiedade, depressão, transtorno de déficit de atenção/hiperatividade e psicose, cabendo aos profissionais o diagnóstico correto e em tempo hábil para auxiliar na qualidade de vida do indivíduo. 

Polymorphism of the APOE Locus in the Azores Islands (Portugal)

Our aim in this study is to report on the polymorphism of the APOE gene in the Azores Islands (Portugal) to obtain a population baseline of the existing variation in this locus, known to be one of the genetic determinants of plasma lipid levels. One hundred twenty-six Azorean individuals were typed for the APOE polymorphism using standard PCR-RFLP. Allele frequencies obtained for APOE*2, APOE*3, and APOE*4 were 6.75%, 83.73%, and 9.52%, respectively. The APOE*3/*3 genotype presented the highest frequency (69.84%), and the APOE*4/*4 genotype had the lowest frequency (0.79%). Genotype frequencies were in conformity with Hardy- Weinberg expectations. The observed genotype and allele frequencies were similar to those reported for other Iberian samples. Furthermore, Nei’s gene diversity (Hˆ 0.2864 0.0351) was similar to that reported for samples from mainland Portugal. The data generated from this study will be of importance in the context of ongoing studies concerning the factors that influence lipid levels in the Azorean population

Annotated corpora and tools of the PARSEME Shared Task on Automatic Identification of Verbal Multiword Expressions (edition 1.1)

This multilingual resource contains corpora in which verbal MWEs have been manually annotated. VMWEs include idioms (let the cat out of the bag), light-verb constructions (make a decision), verb-particle constructions (give up), inherently reflexive verbs (help oneself), and multi-verb constructions (make do). VMWEs were annotated according to the universal guidelines in 19 languages. The corpora are provided in the cupt format, inspired by the CONLL-U format. The corpora were used in the 1.1 edition of the PARSEME Shared Task (2018). For most languages, morphological and syntactic information ­­­­– not necessarily using UD tagsets – including parts of speech, lemmas, morphological features and/or syntactic dependencies are also provided. Depending on the language, the information comes from treebanks (e.g., Universal Dependencies) or from automatic parsers trained on treebanks (e.g., UDPipe). This item contains training, development and test data, as well as the evaluation tools used in the PARSEME Shared Task 1.1 (2018). The annotation guidelines are available online: http://parsemefr.lif.univ-mrs.fr/parseme-st-guidelines/1.