Vector mesons within nonlocal chiral quark models for strong interactions

We analyze meson properties within an SU(2) chiral quark model that includes nonlocal four fermion couplings with wave function renormalization. Model parameters are determined from meson phenomenology, considering different nonlocal form factor shapes. We concentrate in the description of basic features of nonstrange vector and axial vector mesons, considering nonlocal form factors that are based in lattice QCD results for effective quark propagators.Instituto de Física La Plat

Properties of vector and axial-vector mesons in a nonlocal SU(2) PNJL model

We study the features of a SU(2) Polyakov-Nambu-Jona-Lasinio model that includes wave function renormalization and nonlocal vector interactions. Within this framework we analyze, among other properties, the masses, width, and decay constants of light vector and axial-vector mesons at finite temperature. Then we obtain the corresponding phase diagram in a finite density scenario, after characterizing the deconfinement and chiral restoration transitions.Fil: Carlomagno, Juan Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Departamento de Física; ArgentinaFil: Izzo Villafañe, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; Argentin

Modelos quirales para las interacciones fuertes: fenomenología de mesones y transiciones de fase en presencia de campos magnéticos externos

La dinámica de quarks se encuentra descrita en el marco del Modelo Estándar por la Cromodinámica Cuántica (QCD), que formalmente es una teoría de campos de gauge no abeliana. En procesos de altas energías la propiedad de libertad asintótica presente en QCD permite obtener predicciones a partir del lagrangiano fundamental de la teoría. Sin embargo, a bajas energías (≤1 GeV) la constante de acoplamiento fuerte aumenta su valor de modo tal que las técnicas perturbativas ya no son aplicables. En este régimen los quarks se encuentran confinados en hadrones, y la simetría quiral se encuentra espontáneamente rota. El empleo de teorías efectivas permite estudiar la fenomenología de las partículas hadrónicas y analizar el comportamiento de la materia fuertemente interactuante en sistemas con temperatura y densidad finitas. En esta Tesis se estudiaron modelos efectivos para la descripción de la interacción fuerte a bajas energías. En particular, se consideraron modelos de quarks relativistas del tipo Nambu-Jona-Lasinio con interacciones no locales para dos sabores de quarks de modo de estudiar la fenomenología de los mesones livianos. Se estudió también el acoplamiento con campos magnéticos externos uniformes, y el efecto de éstos sobre las propiedades de los mesones y las transiciones de fase que sufre la materia hadrónica a temperatura finita.Facultad de Ciencias Exacta

Strong magnetic fields in nonlocal chiral quark models

We study the behavior of strongly interacting matter under a uniform intense external magnetic field in the context of nonlocal extensions of the Polyakov-Nambu-Jona-Lasinio model. A detailed description of the formalism is presented, considering the cases of zero and finite temperature. In particular, we analyze the effect of the magnetic field on the chiral restoration and deconfinement transitions, which are found to occur at approximately the same critical temperatures. Our results show that these models offer a natural framework to account for the phenomenon of inverse magnetic catalysis found in lattice QCD calculations.Fil: Gomez Dumm, Daniel Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Izzo Villafañe, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Noguera, S.. Universidad de Valencia; EspañaFil: Pagura, Valeria Paula. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Valencia; EspañaFil: Scoccola, Norberto Nerio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; Argentina. Universidad Favaloro; Argentin

Vector mesons within nonlocal chiral quark models for strong interactions

We analyze meson properties within an SU(2) chiral quark model that includes nonlocal four fermion couplings with wave function renormalization. Model parameters are determined from meson phenomenology, considering different nonlocal form factor shapes. We concentrate in the description of basic features of nonstrange vector and axial vector mesons, considering nonlocal form factors that are based in lattice QCD results for effective quark propagators.Instituto de Física La Plat

Properties of vector and axial-vector mesons in a nonlocal SU(2) PNJL model

We study the features of a SU(2) Polyakov-Nambu-Jona-Lasinio model that includes wave function renormalization and nonlocal vector interactions. Within this framework we analyze, among other properties, the masses, width, and decay constants of light vector and axial-vector mesons at finite temperature. Then we obtain the corresponding phase diagram in a finite density scenario, after characterizing the deconfinement and chiral restoration transitions.Instituto de Física La Plat

Properties of magnetized neutral pions at zero and finite temperature in nonlocal chiral quark models

The behavior of π0 meson properties in the presence of a uniform external magnetic field is studied in the context of a nonlocal extension of the Polyakov-Nambu-Jona-Lasinio model. The analysis includes the π0 mass, the effective π0-quark coupling and the pion-to-vacuum hadronic form factors, both at zero and finite temperature. Numerical results are compared with previous calculations carried out within the local NJL model, when available. The validity of chiral relations and the features of deconfinement and chiral symmetry restoration transitions are discussed.Fil: Gomez Dumm, Daniel Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Física La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Física La Plata; ArgentinaFil: Izzo Villafañe, María Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; ArgentinaFil: Scoccola, Norberto Nerio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica; Argentin

Linfoma não-Hodgkin primário do fígado em paciente com SIDA

Non-Hodgkin's lymphomas (NHL) are the second most frequent malignancies in AIDS patients. The majority of NHL associated with AIDS involves extranodal sites, especially the digestive tract and the central nervous system. Primary liver lymphoma (PLL) is an uncommon neoplasm among these patients. Ultrasonography and computed tomography scans may be helpful in the diagnosis of focal hepatic lymphoma. Image-guided fine-needle biopsy with histopathology of the liver lesions is the gold standard for the diagnosis of hepatic lymphoma. We report a case of PLL as the initial manifestation of AIDS in a patient without any previous infection by hepatitis C or B virus, presented as multiple and large hepatic masses.Os linfomas não-Hodgkin (LNH) são as segundas neoplasias mais freqüentes nos pacientes com síndrome da imunodeficiência adquirida (SIDA). A maioria dos LNH associados à AIDS envolvem locais extra-ganglionares, especialmente o trato digestivo e o sistema nervoso central. O linfoma não-Hodgkin primário do fígado (LPF) é uma neoplasia incomum nestes pacientes. A ultrassonografia (US) e a tomografia computadorizada (TC) podem ser úteis no diagnóstico de linfoma não-Hodgkin hepático apresentando-se como lesões multifocais. A biópsia com agulha fina guiada por imagens (US, TC) juntamente com a histopatologia das lesões do fígado constitui o padrão-ouro para o diagnóstico de linfoma hepático. Este trabalho relata um caso de LPF como manifestação inicial de AIDS em um paciente sem infecção prévia pelo vírus da hepatite C e B, que se apresentou como massas hepáticas múltiplas e de grandes dimensões

Strong magnetic fields in nonlocal chiral quark models

We study the behavior of strongly interacting matter under a uniform intense external magnetic field in the context of nonlocal extensions of the Polyakov-Nambu-Jona-Lasinio model. A detailed description of the formalism is presented, considering the cases of zero and finite temperature. In particular, we analyze the effect of the magnetic field on the chiral restoration and deconfinement transitions, which are found to occur at approximately the same critical temperatures. Our results show that these models offer a natural framework to account for the phenomenon of inverse magnetic catalysis found in lattice QCD calculations.Instituto de Física La PlataConsejo Nacional de Investigaciones Científicas y Técnica

First Evidence of Akodon-Borne Orthohantavirus in Northeastern Argentina

Orthohantaviruses (genus Orthohantavirus, family Hantaviridae) are the etiologic agents of Hantavirus Pulmonary Syndrome in the Americas. In South America, orthohantaviruses are highly diverse and are hosted by sigmodontine rodents (subfamiliy Sigmodontinae, family Cricetidae), an also diverse group of rodents. The aims of this work were to (1) identify orthohantavirus hosts and (2) to study the spatial and temporal variations in the prevalence of infection and their associations with community, environmental and individual characteristics, in different environments of Misiones province, northeastern Argentina. Live-capture sessions were carried out during two years in different land uses, with a trapping effort of 31,653 trap nights. We captured 719 individuals from the species Akodon montensis, Rattus rattus, Mus musculus, Calomys tener, Thaptomys nigrita, Oligoryzomys nigripes, Euryoryzomys russatus, Oligoryzomys flavescens, Brucepattersonius sp., and Juliomys pictipes. Antibodies against orthohantavirus were detected in Akodon montensis in one natural protected and one periurban areas, and it was the most abundant species in almost every study sites. We observed the presence of spatial focality of orthohantavirus infection and a positive association with host abundance suggesting the existence of a threshold density. At the individual level, large, reproductively active, and male individuals were more likely to have antibodies against orthohantavirus. This is the first record of orthohantavirus infection in A. montensis in Argentina, which shows the importance of investigations about emerging diseases.Fil: Burgos, Eliana Florencia. Administracion Nacional de Laboratorios E Institutos de Salud "dr. Carlos G. Malbran". Instituto Nacional de Medicina Tropical.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vadell, María Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Administracion Nacional de Laboratorios E Institutos de Salud "dr. Carlos G. Malbran". Instituto Nacional de Medicina Tropical.; ArgentinaFil: Bellomo, Carla María. Dirección Nacional de Instituto de Investigación. Adm.nacional de Laboratorio E Instituto de Salud "dr.c.g.malbran". Instituto Nacional de Enfermedades Infecciosas. Departamento de Virologia; ArgentinaFil: Martinez, Valeria Paula. Dirección Nacional de Instituto de Investigación. Adm.nacional de Laboratorio E Instituto de Salud "dr.c.g.malbran". Instituto Nacional de Enfermedades Infecciosas. Departamento de Virologia; ArgentinaFil: Salomón, Oscar Daniel. Administracion Nacional de Laboratorios E Institutos de Salud "dr. Carlos G. Malbran". Instituto Nacional de Medicina Tropical.; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gomez Villafañe, Isabel Elisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentin