Study of the crossover transition of a gas of extended hadrons

We formulate a simple model for a gas of extended hadrons at zero chemical potential by taking inspiration from the compressible bag model. We show that a crossover transition qualitatively similar to lattice QCD can be reproduced by such a system by including some appropriate additional dynamics. Under certain conditions, at high temperature, the system consists of a finite number of infinitely extended bags, which occupy the entire space. In this situation the system behaves as an ideal gas of quarks and gluons.Comment: 2 pages, 1 figure - To appear in the conference proceedings for Quark Matter 2009, March 30 - April 4, Knoxville, Tennesse

LE VARIETÀ LINGUISTICHE IN CONTESTO INFORMALE: UNO STUDIO DI CASO DI UNA FAMIGLIA ITALIANA IN BRASILE

Il contributo si inserisce all’interno degli studi sull’ecologia linguistica ed esplora le varietà linguistiche in uso in un contesto intrafamiliare di tipo informale, in quanto la famiglia costituisce l’unità di analisi per eccellenza per lo studio dei fenomeni di mantenimento e di trasformazione linguistica. Lo studio di caso è stato svolto all’interno di una famiglia veneta di classe medio-alta, emigrata nel sud del Brasile nell’ultimo decennio, in seguito alla crisi economica che ha investito l’Italia. Un elemento di novità rispetto alle ricerche passate è rappresentato dal repertorio linguistico dei soggetti presi in esame che è piuttosto omogeneo. Infatti, seppur con alcune sfumature, i componenti della famiglia condividono tutti la stessa lingua materna (dialetto veneto - italiano) e hanno imparato il portoghese in un contesto d’immersione. L’analisi mostra che il tessuto discorsivo è composito e attraversato dalla pratica del translinguismo, attivata consapevolmente dai parlanti. Lo spazio linguistico è conteso tra l’italiano e il dialetto veneto contornato dal portoghese che apre momenti dedicati a riflessioni metalinguistiche che attestano il consolidamento di una competenza multilingue.The aim of this survey is to document the language varieties used in an informal intra-family context. The case study focuses on a family with a medium-high level of education from the Veneto Region who, following the last major world economic crisis of 2008, moved to Brazil. This survey falls within studies on linguistic ecology in family contexts and is based on the analysis of a video recording made during a lunch and a questionnaire. The analysis shows that even if Italian remains the prevailing code for all family members, there is a casualness from one code to another (Italian, Venetian dialect and Portuguese) that creates space for metalinguistic reflections at the lexical level. The codes of the repertory overlap but at the same time there are clear boundaries that emphasize the distance from the host culture, although the switching takes place following a precise communicative will. The case study observed highlights how in the case of multilingualism experienced in terms of enrichment among the varieties of the Italian repertoire / dialect available to the speakers, the inclusion of the language of the host country becomes a further element of wealth in addition to the language of origin

Crossover transition in bag-like models

We formulate a simple model for a gas of extended hadrons at zero chemical potential by taking inspiration from the compressible bag model. We show that a crossover transition qualitatively similar to lattice QCD can be reproduced by such a system by including some appropriate additional dynamics. Under certain conditions, at high temperature, the system consist of a finite number of infinitely extended bags, which occupy the entire space. In this situation the system behaves as an ideal gas of quarks and gluons.Comment: Corresponds to the published version. Added few references and changed the titl

Graphene-based nanomaterials for tissue engineering in the dental field

The world of dentistry is approaching graphene-based nanomaterials as substitutes for tissue engineering. Apart from its exceptional mechanical strength, electrical conductivity and thermal stability, graphene and its derivatives can be functionalized with several bioactive molecules. They can also be incorporated into different scaffolds used in regenerative dentistry, generating nanocomposites with improved characteristics. This review presents the state of the art of graphene-based nanomaterial applications in the dental field. We first discuss the interactions between cells and graphene, summarizing the available in vitro and in vivo studies concerning graphene biocompatibility and cytotoxicity. We then highlight the role of graphene-based nanomaterials in stem cell control, in terms of adhesion, proliferation and differentiation. Particular attention will be given to stem cells of dental origin, such as those isolated from dental pulp, periodontal ligament or dental follicle. The review then discusses the interactions between graphene-based nanomaterials with cells of the immune system; we also focus on the antibacterial activity of graphene nanomaterials. In the last section, we offer our perspectives on the various opportunities facing the use of graphene and its derivatives in associations with titanium dental implants, membranes for bone regeneration, resins, cements and adhesives as well as for tooth-whitening procedure

Particle Number Fluctuations in Statistical Model with Exact Charge Conservation Laws

Even though the first momenta i.e. the ensemble average quantities in canonical ensemble (CE) give the grand canonical (GC) results in large multiplicity limit, the fluctuations involving second moments do not respect this asymptotic behaviour. Instead, the asymptotics are strikingly different, giving a new handle in study of statistical particle number fluctuations in relativistic nuclear reactions. Here we study the analytical large volume asymptotics to general case of multispecies hadron gas carrying fixed baryon number, strangeness and electric charge. By means of Monte Carlo simulations we have also studied the general multiplicity probability distributions taking into account the decay chains of resonance states.Comment: 4 pages, 2 figures. The report of the talk given in Strangeness in Quark Matter 2004, Cape Town. Submitted to J. Phys. G: Nucl. Part. Phy

Investigating The Physics Case of Running a B-Factory at the Y(5S) Resonance

We discuss the physics case of a high luminosity B-Factory running at the Y(5S) resonance. We show that the coherence of the B meson pairs is preserved at this resonance, and that Bs can be well distinguished from Bd and charged B mesons. These facts allow to cover the physics program of a traditional B-Factory and, at the same time, to perform complementary measurements which are not accessible at the Y(4S). In particular we show how, despite the experimental limitations in performing time-dependent measurements of Bs decays, the same experimental information can be extracted, in several cases, from the determination of time-integrated observables. In addition, a few examples of the potentiality in measuring rare Bs decays are given. Finally, we discuss how the study of Bs meson will improve the constraints on New Physics parameters in the Bs sector, in the context of the generalized Unitarity Triangle analysis.Comment: 47 pages, 22 figure

Statistical hadronization and hadronic microcanonical ensemble I

We present a full treatment of the microcanonical ensemble of the ideal hadron-resonance gas in a quantum-mechanical framework which is appropriate for the statistical model of hadronization. By using a suitable transition operator for hadronization we are able to recover the results of the statistical theory, particularly the expressions of the rates of different channels. Explicit formulae are obtained for the phase space volume or density of states of the ideal relativistic gas in quantum statistics which, for large volumes, turn to a cluster decomposition whose terms beyond the leading one account for Bose-Einstein and Fermi-Dirac correlations. The problem of the computation of the microcanonical ensemble and its comparison with the canonical one, which will be the main subject of a forthcoming paper, is addressed.Comment: 15 pages, LaTeX macros svjour.cls and svepj.clo needed, revised version to be published in Eur. Phys. J.