102,758 research outputs found
Béroul, Tristano e Isotta, a cura di G. Paradisi
No full textIl volume offre l'edizione del testo con la traduzione a fronte, un saggio introduttivo e un commento
On the interrelationship among leptonic g − 2, EDMs and lepton flavor violation
No full textWe present a concise review of the status of charged lepton flavor violation (cLFV) in scenarios beyond the SM. We emphasize that the current experimental resolutions on cLFV processes are already testing territories of new physics (NP) models well beyond the LHC reach. On the other hand, with the expected sensitivities of next-generation experiments, cLFV will become the most powerful probe of NP signals at our disposal. Finally, the interrelationship among leptonic g − 2, EDMs and cLFV will turn out to be of outmost importance to disentangle among different NP scenarios
Paradisi e paradossi fiscali : il rovescio del diritto tributario internazionale
No full textDopo una crescita irrefrenabile, con un’espansione irreversibile dell’economia globale a cui non si è affiancata una globalizzazione del diritto tributario, la crisi finanziaria ha rimesso in discussione il mondo variopinto dei paradisi fiscali e Giuseppe Marino, direttore del Master in Diritto tributario dell’impresa alla Bocconi e docente di Diritto tributario all’Università di Milano, in ‘Paradisi e paradossi fiscali. Il rovescio del diritto tributario internazionale’ (Egea, 2009, 159 pagine, 18 euro) ha colto l’occasione per fare il punto sui paradisi nel mondo e gli ultimissimi sviluppi in termini di legislazione, in una guida contornata con un pizzico di ironia e leggerezza. “Il desiderio,” spiega Marino, “è di impostare il lavoro come una sorta di caccia al tesoro, dove le competenze tecniche in diritto tributario si fondono con la fantasia del romanzo”. Il libro parte proprio con una guida attraverso le vicende storiche e recenti dei paradisi più rappresentativi, inclusi l’oasi nel deserto di Dubai, il caldo caraibico delle Bahamas e Singapore, la Svizzera asiatica. Segue un’accurata analisi della fisionomia camaleontica dei paradisi, da quelli fiscali a quelli bancari, da quelli societari a quelli penali. Si prosegue con una descrizione delle misure di contrasto messe in atto nel diritto tributario internazionale e da parte degli organismi internazionali mentre un’altra parte si concentra sul rapporto tra l’Italia e i paradisi fiscali negli ultimi 20 anni. Analizzando la situazione, la crisi finanziaria ha ora offerto agli stati, dato che il finanziamento per lo sviluppo non può che venire dal prelievo fiscale, l’occasione per riaffermare i loro poteri sovrani e nulla sembra più come prima dopo che nel marzo scorso la Svizzera ha deciso di assicurare una collaborazione fiscale amministrativa alla comunità internazionale e ha aperto negoziati con diversi stati. Ma, conclude Marino, una vera svolta non è certa e esistono ancora molte zone d’ombra e il rischio che “si profili un orizzonte gattopardesco in cui tutto cambia per non cambiare”
Structural and conformational modification of bioactive peptides through the proline – alpha-aminoacid-chimeras approach
No full text
High precision flavour physics
No full textFlavour Physics is a very powerful tool to test the Standard Model and quantify the effects of New Physics by exploring possible departures from the model. It is necessary, however, to increase the level of precision of the experimental measurements and of the theoretical predictions in order to be sensitive to possible deviations. In this thesis we address this issue by providing theoretical improvements for both non-perturbative and perturbative calculations of some relevant flavour observables. On the one hand, we present a new strategy to renormalize lattice operators in QCD+QED in the RI-MOM scheme, fully including the non perturbative dynamics of QCD, and QED at O(αem). We show how to keep systematically into account all contributions not separable between the two interactions, thus overcoming the factorization approximation in which the mixed effects are neglected. A numerical analysis in the electro-quenched approximation is carried out for quark bilinear operators and for the case of the matrix elements relevant for Kl2 and πl2 processes and for semileptonic decays like Kl3. A detailed discussion of the calculation of the leading isospin breaking corrections to the leptonic decay rates Γ(Kμ2) and Γ(πμ2) is presented. On the other hand, we compute for the first time the anomalous dimension matrices of quark bilinear and weak four-fermions semileptonic operators at O(αs αem), thus improving the evolution and matching of the matrix elements related to such operators in Effective Field Theories
Cercando l'Europa
No full textnumero monografico della rivista "Critica del Testo" (XIII, 3, 2010)Special number of the review "Critica del Testo" (XIII, 3, 2010
Two additional oxyprenylated phenylpropanoids in Citrus paradisi Macfad. seeds extract
No full textTwo additional oxyprenylated phenylpropanoids in Citrus paradisi Macfad. seeds extrac
Testing new physics with the electron g-2
No full textWe argue that the anomalous magnetic moment of the electron (a_e) can be used to probe new physics. We show that the present bound on new-physics contributions to a_e is 8*10^-13, but the sensitivity can be improved by about an order of magnitude with new measurements of a_e and more refined determinations of alpha in atomic-physics experiments. Tests on new-physics effects in a_e can play a crucial role in the interpretation of the observed discrepancy in the anomalous magnetic moment of the muon (a_mu). In a large class of models, new contributions to magnetic moments scale with the square of lepton masses and thus the anomaly in a_mu suggests a new-physics effect in a_e of (0.7 +- 0.2)*10^-13. We also present examples of new-physics theories in which this scaling is violated and larger effects in a_e are expected. In such models the value of a_e is correlated with specific predictions for processes with violation of lepton number or lepton universality, and with the electric dipole moment of the electron.We argue that the anomalous magnetic moment of the electron (a_e) can be used to probe new physics. We show that the present bound on new-physics contributions to a_e is 8*10^-13, but the sensitivity can be improved by about an order of magnitude with new measurements of a_e and more refined determinations of alpha in atomic-physics experiments. Tests on new-physics effects in a_e can play a crucial role in the interpretation of the observed discrepancy in the anomalous magnetic moment of the muon (a_mu). In a large class of models, new contributions to magnetic moments scale with the square of lepton masses and thus the anomaly in a_mu suggests a new-physics effect in a_e of (0.7 +- 0.2)*10^-13. We also present examples of new-physics theories in which this scaling is violated and larger effects in a_e are expected. In such models the value of a_e is correlated with specific predictions for processes with violation of lepton number or lepton universality, and with the electric dipole moment of the electron
New physics behind the new muon -2 puzzle?
No full textThe recent measurement of the muon -2 at Fermilab confirms the previous
Brookhaven result. The leading hadronic vacuum polarization (HVP) contribution
to the muon -2 represents a crucial ingredient to establish if the Standard
Model prediction differs from the experimental value. A recent lattice QCD
result by the BMW collaboration shows a tension with the low-energy data which are currently used to determine the HVP
contribution. We refer to this tension as the new muon -2 puzzle. In this
Letter we consider the possibility that new physics contributes to the cross-section. This scenario could, in principle, solve the
new muon -2 puzzle. However, we show that this solution is excluded by a
number of experimental constraints.Comment: 6 pages, 4 figures. Typo in Fig. 4 (left panel) correcte
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