Phase diagram and isentropic curves from the vector meson extended Polyakov quark meson model

In the framework of the $N_f = 2+1$ flavor (axial)vector meson extended Polyakov quark meson model we investigate the QCD phase diagram at finite temperature and density. We use a $\chi^2$ minimization procedure to parameterize the model based on tree\,-\,level decay widths and vacuum scalar and pseudoscalar curvature masses which incorporate the contribution of the constituent quarks. Using a hybrid approximation (mesons at tree level, fermions at one\,-\,loop level) for the grand potential we determine the phase boundary both on the $\mu_B-T$ and $\rho-T$ planes. We also determine the location of the critical end point of the phase diagram. Moreover by calculating the pressure and other thermodynamical quantities derived from it, we determine a set of isentropic curves in the crossover region. We show that the curves behave very similarly as their counterparts obtained from the lattice in the crossover regime.Comment: 6 pages, 4 figures, Presented at Excited QCD 2017, 7-13 May 2017, Sintra, Portuga

Chiral phase transition scenarios from the vector meson extended Polyakov quark meson model

Chiral phase transition is investigated in an $SU(3)_L \times SU(3)_R$ symmetric vector meson extended linear sigma model with additional constituent quarks and Polyakov loops (extended Polyakov quark meson model). The parameterization of the Lagrangian is done at zero temperature in a hybrid approach, where the mesons are treated at tree-level, while the constituent quarks at 1-loop level. The temperature and baryochemical potential dependence of the two assumed scalar condensates are calculated from the hybrid 1-loop level equations of states. The order of the phase transition along the $T=0$ and $\mu_B=0$ axes are determined for various parameterization scenarios. We find that in order to have a first order phase transition at $T=0$ as a function of $\mu_B$ a light isoscalar particle is needed.Comment: 6 pages, 2 figures, Presented at Excited QCD 2015 (8-14 March 2015, Tatranska Lomnica, Slovakia

Service-oriented Context-aware Framework

Location- and context-aware services are emerging technologies in mobile and desktop environments, however, most of them are difficult to use and do not seem to be beneficial enough. Our research focuses on designing and creating a service-oriented framework that helps location- and context-aware, client-service type application development and use. Location information is combined with other contexts such as the users' history, preferences and disabilities. The framework also handles the spatial model of the environment (e.g. map of a room or a building) as a context. The framework is built on a semantic backend where the ontologies are represented using the OWL description language. The use of ontologies enables the framework to run inference tasks and to easily adapt to new context types. The framework contains a compatibility layer for positioning devices, which hides the technical differences of positioning technologies and enables the combination of location data of various sources

Chiral phase transition in the vector meson extended linear sigma model

In the framework of an SU(3) (axial)vector meson extended linear sigma model with additional constituent quarks and Polyakov loops, we investigate the effects of (axial)vector mesons on the chiral phase transition. The parameters of the Lagrangian are set at zero temperature and we use a hybrid approach where in the effective potential the constituent quarks are treated at one-loop level and all the mesons at tree-level. We have four order parameters, two scalar condensates and two Polyakov loop variables and their temperature and baryochemical potential dependence are determined from the corresponding field equations. We also investigate the changes of the tree-level scalar meson masses in the hot and dense medium.Comment: 5 pages, 6 figure

A statistical method to estimate low-energy hadronic cross sections

In this article we propose a model based on the Statistical Bootstrap approach to estimate the cross sections of different hadronic reactions up to a few GeV in c.m.s energy. The method is based on the idea, when two particles collide a so called fireball is formed, which after a short time period decays statistically into a specific final state. To calculate the probabilities we use a phase space description extended with quark combinatorial factors and the possibility of more than one fireball formation. In a few simple cases the probability of a specific final state can be calculated analytically, where we show that the model is able to reproduce the ratios of the considered cross sections. We also show that the model is able to describe proton\,-\,antiproton annihilation at rest. In the latter case we used a numerical method to calculate the more complicated final state probabilities. Additionally, we examined the formation of strange and charmed mesons as well, where we used existing data to fit the relevant model parameters.Comment: 12 pages, 12 figures, submitted to EPJ

Burgus building inscriptions of Commodus from Pannonia

In this paper the author examines the case of the building of burgi and praesidia in Pannonia under the reign of Commodus that is attested by a series of inscriptions on the limes between Aquincum and Intercisa. A separated part is devoted to the question what the word paesidium could mean, i. e. most probably a smaller fortlet. The buildings were suddenly interrupted because of Perennis’ conspiracy around 185. ___________________________________________ Der Verfasser beschäftigt sich in diesem Beitrag mit den Bauinschriften von Burgi und Praesidia in Pannonia Inferior aus der Zeit von Commodus.Eine Reihe (insgesamt 16 Inschriften) von Bauinschriften ist aus der Limesstrecke Aquincum-Intercisa bekannt. Nach dem Verf. bedeutet das Wort praesidium ein kleineres Kastell, wie die antiken Quellen bezeugen. Das Bauprogramm wurde plötzlich nach dem Sturz des Legatus Augusti, L.Cornelius Felix Plotianus wegen der Teilnahme in der Verschwörung von Perennis im Jahre 185 n. Chr. aufgegeben