The QCD Critical End Point in the Context of the Polyakov--Nambu--Jona-Lasinio Model

We investigate the phase diagram of the so-called Polyakov--Nambu--Jona-Lasinio model at finite temperature and nonzero chemical potential with three quark flavors. Chiral and deconfinement phase transitions are discussed, and the relevant order-like parameters are analyzed. A special attention is payed to the critical end point (CEP): the influence of the strangeness on the location of the CEP is studied; also the strength of the flavor-mixing interaction alters the CEP location, once when it becomes weaker the CEP moves to low temperatures and can even disappear.Comment: Prepared for Strangeness in Quark Matter 2011, Sept. 18--24, Cracow, Polan

Exploring the role of model parameters and regularization procedures in the thermodynamics of the PNJL model

The equation of state and the critical behavior around the critical end point are studied in the context of the Polyakov--Nambu--Jona--Lasinio model. We prove that a convenient choice of the model parameters is crucial to get the correct description of isentropic trajectories. The physical relevance of the effects of the regularization procedure is insured by the agreement with general thermodynamic requirements. The results are compared with simple thermodynamic expectations and lattice data.Comment: Talk given at XIII International Conference on Hadron Spectroscopy (Hadron 2009), Tallahassee, Florida, USA, 29 Nov - 4 Dec, 200

A importância do contexto cultural para a comunicação empresarial: um breve enquadramento

O modo como as empresas olham cada vez mais para o mundo como o seu mercado potencial faz com que o sucesso dos negócios internacionais dependa em grande medida da eficácia da comunicação em contexto intercultural. Estudar e relacionar a comunicação intercultural e a comunicação empresarial faz por isso muito sentido. O que distingue a comunicação intercultural de outros tipos de comunicação é a interacção entre pessoas percebidas como diferentes de nós. No entanto, é fácil perdermo-nos neste conceito e nas suas implicações. Este texto procura, por isso, contextualizar a noção de cultura, os seus níveis e as suas dimensões, assim como identificar barreiras à comunicação intercultural. Uma análise e investigação mais profunda das teorias pode levar-nos a concordar ou a discordar sobre os seus resultados e sobre o que elas advogam. Porém, do nosso ponto de vista, esse não será o aspecto mais importante. Fundamental na sua leitura e revisão será a ajuda que nos dará a entender melhor a nossa cultura, a encontrar e a perceber as diferenças em relação às outras, a antecipar os riscos e as formas de minimizar o seu impacto, a tornar-nos comunicadores interculturais mais eficazes e, como consequência, a obter melhores resultados.The way in which companies increasingly look to the whole world as their potential market means that international business success largely depends on the effectiveness of intercultural communication. Thus, it makes sense to study and to link intercultural communication to international business and to business communication. What distinguishes intercultural communication from other types of communication is the interaction between people perceived as different from us. However, we can easily fail to understand these concepts and their implications. We will then try to address some issues such as culture, levels of cultures and dimensions of cultures, as well as some barriers to intercultural communication. Further analysis and investigation into these theories can lead us to agree or to disagree with them and with their results. But from our point of view, this is not the key aspect. What is important in reading and reviewing them is to get a better understanding of our own culture, to identify and understand the differences in relation to others, to anticipate the risks and the means to minimize their impact, to become more effective intercultural communicators and, consequently, to achieve better results

How parameters and regularization affect the PNJL model phase diagram and thermodynamic quantities

We explore the phase diagram and the critical behavior of QCD thermodynamic quantities in the context of the so-called Polyakov--Nambu--Jona-Lasinio model. We show that this improved field theoretical model is a successful candidate for studying the equation of state and the critical behavior around the critical end point. We argue that a convenient choice of the model parameters is crucial to get the correct description of isentropic trajectories. The effects of the regularization procedure in several thermodynamic quantities is also analyzed. The results are compared with simple thermodynamic expectations and lattice data.Comment: 27 pages, 7 figures, 4 tables; PRD versio

Restoration of UA_A(1) symmetry and meson spectrum in hot or dense matter

We explore the effects of breaking and restoration of chiral and axial symmetries using an extended three-flavor Nambu-Jona-Lasinio model that incorporates explicitly the axial anomaly through the 't Hooft interaction. We implement a temperature (density) dependence of the anomaly coefficient motivated by lattice results for the topological susceptibility. The spectrum of scalar and pseudoscalar mesons is analyzed bearing in mind the identification of chiral partners and the study of its convergence. We also concentrate on the behavior of the mixing angles that give us relevant information on the issue under discussion. The results suggest that the axial part of the symmetry is restored before the possible restoration of the full U(3)$\otimes$U(3) chiral symmetry might occur.Comment: 9 pages, 5 figures. Talk given at Joint Meeting Heidelberg-Liege-Paris-Rostock (HLPR 2004), Spa, Belgium, 16-18 Dec 200