4,241 research outputs found

    Aspects of symmetry breaking in SO(10) GUTs

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    I review some recent results on the Higgs sector of minimal SO(10) grand unified theories both with and without supersymmetry. It is shown that nonsupersymmetric SO(10) with just one adjoint triggering the first stage of the symmetry breaking does provide a successful gauge unification when radiative corrections are taken into account in the scalar potential, while in the supersymmetric case it is argued that the troubles in achieving a phenomenologically viable breaking with representations up to the adjoint are overcome by considering the flipped SO(10) embedding of the hypercharge.Comment: 8 pages, 1 figure; prepared for the proceedings of DISCRETE'10 - Symposium on Prospects in the Physics of Discrete Symmetrie

    On soft breaking and CP phases in the supersymmetric standard model

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    We consider a class of N=1 supersymmetric extensions of the Standard Model in which the soft breaking sector is CP conserving at the GUT scale. We study the question of whether the presence of explicit CP violation in the Yukawa sector of the theory induces through renormalization effects CP violating phases in the soft terms, which could lead to observable effects. A clear pattern appears in the structure of phases in the soft sector. In particular, the inclusion of intergenerational mixing induces large phases in the flavour mixing entries of the trilinear soft breaking terms, whereas the diagonal entries remain real. A mechanism is proposed for generating through chargino exchange a contribution to the neutron electric dipole moment which can be a few orders of magnitude larger that that of the Standard Model, although still out of reach of experimental tests. We comment on the possible relevance of these phases for baryogenesis at the weak scale in minimal supersymetric scenarios, recently considered in the literature.Comment: 12 pages + 1 figure (postscript file available on request), LATEX, SISSA 173/93/E

    Supersymmetry breaking at the end of a cascade of Seiberg dualities

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    We study the IR dynamics of the cascading non-conformal quiver theory on N regular and M fractional D3 branes at the tip of the complex cone over the first del Pezzo surface. The horizon of this cone is the irregular Sasaki-Einstein manifold Y^{2,1}. Our analysis shows that at the end of the cascade supersymmetry is dynamically broken.Comment: 12 pages, 2 figures, minor changes, typos correcte

    Le specificità del sistema agro-alimentare nella ricostruzione post-sisma

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    Anche il cosiddetto ‘cratere agricolo’ ha pagato un prezzo molto elevato a seguito degli eventi sismici del maggio 2012 in Emilia. Tutte le principali produzioni agro-industriali del territorio hanno subito gravi danni: si pensi ai caseifici e magazzini di stagionatura per la produzione di Parmigiano Reggiano, alle cantine e acetaie, alle celle frigorifere per la conservazione dei prodotti ortofrutticoli. Il presente lavoro analizza i principali elementi di specificità che, rispetto ad una forte vulnerabilità settoriale, hanno caratterizzato la ricostruzione del patrimonio agricolo e agro-industriale del cratere. Grande attenzione è data, ad esempio, alla risposta istituzionale per la ricostruzione. Come il settore industriale, infatti, anche il settore agro-alimentare ha beneficiato dei contributi per la ricostruzione attraverso la piattaforma SFINGE. Tuttavia, esso ha altresì beneficiato delle risorse stanziate attraverso il FEASR (Fondo Europeo Agricolo per lo Sviluppo Rurale): l’attivazione di specifiche misure ha permesso di sostenere l’intero territorio del cratere del sisma. Un ulteriore elemento di specificità evidenziato è rappresentato dal tema dell’associazionismo (attivazione di accordi di filiera, interventi di solidarietà e mutualistici) e dal ruolo ricoperto dai Consorzi di Tutela delle produzioni tipiche. Il lavoro dunque evidenzia come, nonostante le criticità riscontrate, il settore agro-alimentare abbia saputo cogliere alcune opportunità dall’evento sismico, soprattutto in termini di capacità innovativa. Abstract: The 2012 earthquake in Emilia-Romagna (Italy) affected a broad area that is characterized by the presence of important industrial and agricultural districts. Indeed, dairies producing Parmigiano Reggiano cheese, firms producing balsamic vinegar of Modena (acetaie) as well as wineries have been particularly damaged. This work focuses on those specific features of agricultural activities that have affected the reconstruction process as well. According to those specificities, the paper points out regulatory interventions that were approved, aiming to guarantee appropriate financial support to the agri-industrial activities damaged by the earthquake. Specific focus is devoted to the role played by the European Agricultural Fund for Rural Development (EAFRD). Eventually, the role played by the cooperative system is stressed as well. According to this analysis, agri-food sector has been proven quite innovative, despite many limits affecting it

    Black hole - D-brane correspondence: An example

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    We explore the connection between D-branes and black holes in one particular case: a D3D3-brane compactified to four dimensions on T6/Z3T^6/Z_3. Using the DD-brane boundary state description we show the equivalence with a double extremal N=2 black hole solution of four dimensional supergravity.Comment: 15 pages, LaTeX. Contribution by C. Nunez to the conference Quantum Gravity in the Southern Cone, Bariloche 7-10 January 1998; to appear in the proceeding

    Direct CP Violation in B->phi K_s and New Physics

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    In the presence of large New Physics contributions to loop-induced b->s transitions, sizable direct CP violation in B-> phi K decays is expected on general grounds. We compute explicitly CP-violating effects using QCD factorization and find that, even in the restricted case in which New Physics has the same penguin structure as the Standard Model, the rate asymmetry can be of order one. We briefly discuss a more general scenario and comment on the inclusion of power-suppressed corrections to factorization.Comment: 3 page

    Supersymmetry breaking deformations and phase transitions in five dimensions

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    We analyze a recently proposed supersymmetry breaking mass deformation of the E1 superconformal fixed point in five dimensions which, at weak gauge coupling, leads to pure SU(2) Yang-Mills and which was conjectured to lead to an interacting CFT at strong coupling. We provide an explicit geometric construction of the deformation using brane-web techniques and show that for large enough gauge coupling a global symmetry is spontaneously broken and the theory enters a new phase which, at infinite coupling, displays an instability. The Yang-Mills and the symmetry broken phases are separated by a phase transition. Depending on the structure of the potential, this can be first or second order

    Poverty and Social Exclusion in the European Union: South-Eastern Territorial Patterns

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    Despite the ambitious goals of promoting inclusive growth in the Europe 2020 strategy, the number of people at risk of poverty in European Union is still growing. The paper moves from the hypothesis that poverty may show distinctive social patterns, which couple with a given spatial dimension and therefore can be defined as a spatially heterogeneous phenomenon at both national and sub-national level. Using the available data from Eurostat on income and living conditions (EUSILC) at NUTS2 level, the paper highlights the different territorial patterns in shaping the risk of exclusion across the EU regions. Focusing on the regions of the Southern and Eastern peripheral EU Member States (MSs), the paper outlines the differences emerging from the results achieved by the EU MSs in applying the Europe 2020 Strategy. Moreover, it deepens the analysis of the poverty drivers at the regional level. The paper shows that the peripheral countries of EU are more vulnerable to poverty but different patterns emerge when comparing Mediterranean and Eastern countries, especially with regard to the material deprivation and the drivers influencing poverty and risk of exclusion
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