Modification of the B meson mass in a magnetic field from QCD sum rules

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

QCD sum rules calculation of heavy Λ semileptonic decay

We set up sum rules for heavy lambda decays in a full QCD calculation which in the heavy quark mass limit incorporates the symmetries of heavy quark effective theory. For the semileptonic Λc decay we obtain a reasonable agreement with experiment. For the Λb semileptonic decay we find at the zero recoil point a violation of the heavy quark symmetry of about 20%. © 1998 Published by Elsevier Science B.V. All rights reserved.

Szegö polynomials: quadrature rules on the unit circle and on [-1, 1]

We consider some of the relations that exist between real Szegö polynomials and certain para-orthogonal polynomials defined on the unit circle, which are again related to certain orthogonal polynomials on [-1, 1] through the transformation x = (z1/2+z1/2)/2. Using these relations we study the interpolatory quadrature rule based on the zeros of polynomials which are linear combinations of the orthogonal polynomials on [-1, 1]. In the case of any symmetric quadrature rule on [-1, 1], its associated quadrature rule on the unit circle is also given.

Connections between the Sznajd model with general confidence rules and graph theory

The Sznajd model is a sociophysics model that is used to model opinion propagation and consensus formation in societies. Its main feature is that its rules favor bigger groups of agreeing people. In a previous work, we generalized the bounded confidence rule in order to model biases and prejudices in discrete opinion models. In that work, we applied this modification to the Sznajd model and presented some preliminary results. The present work extends what we did in that paper. We present results linking many of the properties of the mean-field fixed points, with only a few qualitative aspects of the confidence rule (the biases and prejudices modeled), finding an interesting connection with graph theory problems. More precisely, we link the existence of fixed points with the notion of strongly connected graphs and the stability of fixed points with the problem of finding the maximal independent sets of a graph. We state these results and present comparisons between the mean field and simulations in Barabasi-Albert networks, followed by the main mathematical ideas and appendices with the rigorous proofs of our claims and some graph theory concepts, together with examples. We also show that there is no qualitative difference in the mean-field results if we require that a group of size q > 2, instead of a pair, of agreeing agents be formed before they attempt to convince other sites (for the mean field, this would coincide with the q-voter model).

DeCS terminology and the new rules on orthography of Portuguese language: guidelines for an update

PURPOSE: To indicate orthographic changes to be used as a basic reference for professionals, researchers, doctors, teachers, students and users, which are directly linked and performing activities in health services in general, aimed at implementing the correct orthography in recovery and production of their scientific studies. METHODS: For data collection, were shown some examples of terminology DeCS (Descriptors in Health Science) analyzed according to the current spelling and compared with the Orthographic Vocabulary of Portuguese Language (VOLP). RESULTS: It was select and listed examples of key words and/or terms related to Health Sciences, which was compared to the respective rules of the Orthographic Agreement of Portuguese Language, and divided into three items: graphical accentuation, the non use of dieresis and exceptions and, the use of hyphen. CONCLUSION: This study show some guidelines for the orthographic alterations of the terms used by scientific community, according the new orthographic rules, contributing for the efficiency in the description of the documents and consequently in their recovery.

Exotic B-c-like molecules in QCD sum rules

We use the QCD sum rules to study possible B-c-like molecular states. We consider isoscalar J(P) = 0(+) and J(P) = 1(+) D(*) B(*) molecular currents. We consider the contributions of condensates up to dimension eight and we work at leading order in alpha(s). We obtain for these states masses around 7 GeV. (C) 2012 Elsevier B.V. All rights reserved.

QCD sum rules for the 'Z POT + IND C' (3900) state.

We use the QCD sum rules to study the recently observed charmonium-like structure Z+ c (3900) as a tetraquark state. We evaluate the three-point function and extract the coupling constants of the Z+ c J/ψ π+, Z+ c ηc ρ+ and Z+ c D+ ¯D∗0 vertices and the corresponding decay widths in these channels. The results obtained are in good agreement with the experimental data and supports to the tetraquark picture of this state.

The charmed pentaquark Θc(3250) from QCD sum rules.

We study, using the QCD sum rule framework, the possible existence of a charmed pentaquark that we call Θc(3250). In the QCD side we work at leading order in αs and consider condensates up to dimension 10. The mass obtained: mΘc = (3.21±0.13) GeV, is compatible with the mass of the structure seen by BaBar Collaboration in the decay channel B− → ￣p Σ++ c π−π−.

Constraint handling rules. Compositional semantics and program transformation

This thesis intends to investigate two aspects of Constraint Handling Rules (CHR). It proposes a compositional semantics and a technique for program transformation. CHR is a concurrent committed-choice constraint logic programming language consisting of guarded rules, which transform multi-sets of atomic formulas (constraints) into simpler ones until exhaustion [Frü06] and it belongs to the declarative languages family. It was initially designed for writing constraint solvers but it has recently also proven to be a general purpose language, being as it is Turing equivalent [SSD05a]. Compositionality is the first CHR aspect to be considered. A trace based compositional semantics for CHR was previously defined in [DGM05]. The reference operational semantics for such a compositional model was the original operational semantics for CHR which, due to the propagation rule, admits trivial non-termination. In this thesis we extend the work of [DGM05] by introducing a more refined trace based compositional semantics which also includes the history. The use of history is a well-known technique in CHR which permits us to trace the application of propagation rules and consequently it permits trivial non-termination avoidance [Abd97, DSGdlBH04]. Naturally, the reference operational semantics, of our new compositional one, uses history to avoid trivial non-termination too. Program transformation is the second CHR aspect to be considered, with particular regard to the unfolding technique. Said technique is an appealing approach which allows us to optimize a given program and in more detail to improve run-time efficiency or spaceconsumption. Essentially it consists of a sequence of syntactic program manipulations which preserve a kind of semantic equivalence called qualified answer [Frü98], between the original program and the transformed ones. The unfolding technique is one of the basic operations which is used by most program transformation systems. It consists in the replacement of a procedure-call by its definition. In CHR every conjunction of constraints can be considered as a procedure-call, every CHR rule can be considered as a procedure and the body of said rule represents the definition of the call. While there is a large body of literature on transformation and unfolding of sequential programs, very few papers have addressed this issue for concurrent languages. We define an unfolding rule, show its correctness and discuss some conditions in which it can be used to delete an unfolded rule while preserving the meaning of the original program. Finally, confluence and termination maintenance between the original and transformed programs are shown. This thesis is organized in the following manner. Chapter 1 gives some general notion about CHR. Section 1.1 outlines the history of programming languages with particular attention to CHR and related languages. Then, Section 1.2 introduces CHR using examples. Section 1.3 gives some preliminaries which will be used during the thesis. Subsequentely, Section 1.4 introduces the syntax and the operational and declarative semantics for the first CHR language proposed. Finally, the methodologies to solve the problem of trivial non-termination related to propagation rules are discussed in Section 1.5. Chapter 2 introduces a compositional semantics for CHR where the propagation rules are considered. In particular, Section 2.1 contains the definition of the semantics. Hence, Section 2.2 presents the compositionality results. Afterwards Section 2.3 expounds upon the correctness results. Chapter 3 presents a particular program transformation known as unfolding. This transformation needs a particular syntax called annotated which is introduced in Section 3.1 and its related modified operational semantics !0t is presented in Section 3.2. Subsequently, Section 3.3 defines the unfolding rule and prove its correctness. Then, in Section 3.4 the problems related to the replacement of a rule by its unfolded version are discussed and this in turn gives a correctness condition which holds for a specific class of rules. Section 3.5 proves that confluence and termination are preserved by the program modifications introduced. Finally, Chapter 4 concludes by discussing related works and directions for future work.

Ex-post Liability Rules in Modern Patent Law

This doctoral thesis examines the use of liability rules to protect patent entitlements, focusing on a specific type of rule named ex-post since it is applied and designed ex-post by a court or an agency. The research starts from the premise that patents are defined by the legal and economic scholarship as exclusive rights but nevertheless, under certain circumstances there are economic as well as other compelling reasons to transform the exclusiveness of patent rights into a right to receive compensation.

Controlled foreign companies (CFC) e delocalizzazione delle attività economiche nel diritto interno e nell'ordinamento europeo

Le ragioni della delocalizzazione sono molteplici e di differente natura. Si delocalizza, in primo luogo, per ragioni di stampo economico, finanziario eccetera, ma questa spinta naturale alla delocalizzazione è controbilanciata, sul piano strettamente tributario, dall’esigenza di preservare il gettito e da quella di controllare la genuinità della delocalizzazione medesima. E’ dunque sul rapporto tra “spinte delocalizzative” dell’impresa, da un lato, ed esigenze “conservative” del gettito pubblico, dall’altro, che si intende incentrare il presente lavoro. Ciò alla luce del fatto che gli strumenti messi in campo dallo Stato al fine di contrastare la delocalizzazione (più o meno) artificiosa delle attività economiche devono fare i conti con i principi comunitari introdotti con il Trattato di Roma e tratteggiati negli anni dalla giurisprudenza della Corte di Giustizia. In quest’ottica, la disciplina delle CFC costituisce un ottimo punto di partenza per guardare ai fenomeni di produzione transnazionale della ricchezza e agli schemi di ordine normativo preposti alla tassazione di codesta ricchezza. Ed infatti, le norme sulle CFC non fanno altro che omogeneizzare un sistema che, altrimenti, sarebbe lasciato alla libera iniziativa degli uffici fiscali. Tale “normalizzazione”, peraltro, giustifica le esigenze di apertura che sono incanalate nella disciplina degli interpelli disapplicativi. Con specifico riferimento alla normativa CFC, assumono particolare rilievo la libertà di stabilimento ed il principio di proporzionalità anche nella prospettiva del divieto di abuso del diritto. L’analisi dunque verterà sulla normativa CFC italiana con l’intento di comprendere se codesta normativa, nelle sue diverse sfaccettature, possa determinare situazioni di contrasto con i principi comunitari. Ciò anche alla luce delle recenti modifiche introdotte dal legislatore con il d.l. 78/2009 in un quadro normativo sempre più orientato a combattere le delocalizzazioni meramente fittizie.

Analisi di tendenza per ozono e CFC-11 nella serie decennale delle misure di MIPAS in stratosfera e alta troposfera

Lo strumento MIPAS, operativo a bordo del satellite polare ENVISAT negli anni dal 2002 al 2012, ha misurato spettri di emissione nel medio infrarosso utilizzando la tecnica di scansione del lembo atmosferico. L'Agenzia Spaziale Europea (ESA), mediante un algoritmo di inversione ottimizzato, ha ricavato dagli spettri di MIPAS la distribuzione verticale di diversi composti chimici minoritari in stratosfera e alta troposfera. Tra questi composti figurano l'ozono (O3) e il CFC-11. Lo strato di ozono stratosferico svolge una funzione fondamentale come schermo della radiazione ultravioletta solare, altrimenti dannosa per gli esseri viventi sulla terra. D'altra parte, da alcuni decenni i cosiddetti cloro-fluoro carburi (CFC), tra cui la molecola di CCl3F (indicata sinteticamente con la sigla CFC-11) sono ritenuti responsabili della diminuzione generale dell'ozono stratosferico. Per questo motivo nel 1987 a Montreal è stato siglato un accordo internazionale per limitare l'immissione dei CFC in atmosfera. A partire dalla fine degli anni '80, in base a questo accordo, ci si aspetta quindi una progressiva riduzione dei CFC e un conseguente graduale recupero della concentrazione di ozono. Le misure di MIPAS, con copertura geografica globale, offrono una possibilità assai interessante per la verifica di queste tendenze attese. In questo lavoro di tesi, i profili verticali di frazione volumetrica (VMR) di ozono e CFC-11 ricavati dal processore di ESA versione 6.0 sono stati interpolati a livelli di pressione costante, raggruppati per bande di latitudine e mediati su intervalli di tempo mensili. Abbiamo quindi sviluppato un modello di tendenza parametrico che include un termine costante, uno lineare, due termini dell'oscillazione quasi biennale (QBO), un termine di flusso solare radio e diversi termini armonici in seno e coseno con periodo diverso. Il modello è stato quindi adattato mediante un algoritmo di minimizzazione di Levenberg-Marquardt alle medie mensili ottenute dalle misure di MIPAS per tutto il periodo che va da luglio 2002 ad aprile 2012. Le stime di tendenza ottenute per ozono e CFC-11 sono statisticamente significative e, a seconda della latitudine e del livello di pressione considerato, assumono una gamma di valori che va da -0.15 ppmv/decade a +0.44 ppmv/decade per l'ozono e una gamma di valori che va da -50.2 pptv/decade a +6.5 pptv/decade per il CFC-11. Abbiamo ottenuto tendenze per la maggior parte leggermente positive per l'ozono e quasi ovunque fortemente negative per il CFC-11, risultato in accordo con le disposizioni emanate a seguito del Protocollo di Montreal e in buon accordo anche con lavori precedentemente pubblicati in letteratura. Infine abbiamo stimato l'errore sistematico sulle tendenze ricavate, causato dalla deriva strumentale dovuta alla non-linearità della risposta dei rivelatori, che varia a seguito dell'invecchiamento dei rivelatori stessi.