Relativistic approach to one nucleon knockout reactions

We develop a fully relativistic distorted wave impulse approximation model for electron- and photon-induced one proton knockout reactions. The relativistic mean field for the bound state and the Pauli reduction for the scattering state are used, including a fully relativistic electromagnetic current operator. Results for 16O(e,e'p) cross section and structure functions are shown in various kinematic conditions and compared with nonrelativistic calculations. Nuclear transparency calculations in a Q^2 range between 0.3 and 1.8 (GeV/c)^2 are presented. Results for 16O(gamma,p) differential cross sections are displayed in an energy range between 60 and 150 MeV including two-body seagull contribution in the nuclear current.Comment: 4 pages, 4 figures, REVTeX4. Talk presented by Andrea Meucci at the IX Workshop on Theoretical Nuclear Physics in Italy, Cortona, Italy, 9-12 October 200

Strange quark effects in electron and neutrino-nucleus quasi-elastic scattering

The role of the sea quarks to ground state nucleon properties with electroweak probes is discussed. A relativistic Green's function approach to parity violating electron scattering and a distorted-wave impulse-approximation applied to charged- and neutral-current neutrino-nucleus quasi-elastic scattering are presented in view of the possible determination of the strangeness content of the nucleon.Comment: 6 pages, 3 figures, talk given at 11th Conference on Problems in Theoretical Nuclear Physics, Cortona, Italy, 11-14 October 200

The hadronic vacuum polarization contribution to (gμ−2)(g_\mu-2): Lattice QCD+QED calculations

The anomalous magnetic moment of the muon $a_\mu$ is one of the most accurate quantities in Particle Physics. The long-standing discrepancy of about $3.7$ standard deviations between the experimental value and the prediction of the Standard Model could represent an intriguing indication of New Physics. The experiments at Fermilab (E989) and at J-PARC (E34) aim at reducing significantly the experimental uncertainty, thus making the theoretical one due to hadronic corrections the main limitation of this stringent test of the Standard Model. In this contribution we present the results of a first-principles lattice calculation of the hadronic vacuum polarization (HVP) contribution to $a_\mu$, including electromagnetic and $SU(2)$-breaking corrections. Our determination, $a_\mu^{\rm HVP} = 682.0 ~ (18.7) \cdot 10^{-10}$, turns out to be in agreement with recent theoretical determinations based on the dispersive analyses of the experimental cross section data for the annihilation process $e^+e^- \to hadrons$. Furthermore, we provide for the first time a lattice estimate for the missing part of $a_\mu^{\rm HVP}$ not covered in the MUonE experiment, $\left[a_\mu^{\rm HVP}\right]_> = 91.6 ~ (2.0) \cdot 10^{-10}$.Comment: Invited plenary talk at IFAE 2019, Napoli (Italy), 08-10 April 2019. v2: extended version, 5 pages, 1 figur

Relativistic descriptions of final-state interactions in neutral-current neutrino-nucleus scattering at MiniBooNE kinematics

The analysis of the recent neutral-current neutrino-nucleus scattering cross sections measured by the MiniBooNE Collaboration requires relativistic theoretical descriptions also accounting for the role of final state interactions. In this work we evaluate differential cross sections with the relativistic distorted-wave impulse-approximation and with the relativistic Green's function model to investigate the sensitivity to final state interactions. The role of the strange-quark content of the nucleon form factors is also discussed.Comment: 8 pages, 5 figure

Elastic and quasi-elastic electron scattering off nuclei with neutron excess

We present theoretical predictions for electron scattering on oxygen and calcium isotopic chains. The calculations are done within the framework of the distorted-wave Born approximation and the proton and neutron density distributions are evaluated adopting a relativistic Dirac-Hartree model. We present results for the elastic and quasi-elastic cross sections and for the parity-violating asymmetry. As a first step, the results of the models are tested in comparison with some of the data available for elastic and quasi-elastic scattering on 16O and 40Ca nuclei. Then, the evolution of some nuclear properties is investigated as a function of the neutron number. We also present a comparison with the parity-violating asymmetry parameter obtained by the PREX Collaboration on 208Pb and give a prediction for the future experiment CREX on 48Ca.Comment: 37 pages, 17 figures. version accepted for publication in the Physical Review C. arXiv admin note: text overlap with arXiv:0809.4124 by other author

Chapter New Perspectives on Nation-building and Orientalism in Italy from the Risorgimento to the Republic

In this introductory essay, the editors discuss the new perspectives offered by the volume on travel literature, the question of nation-building and the history of orientalism and oriental studies in Post-unification Italy. In particular, the authors describe the methodological potential of the concept of rereading and discuss the intertwinement between the (re)uses of travel literature and the processes of nation-building in Italy. Furthermore, the editors highlight the open character of the notion of “travellers” adopted in the essays and underline the importance of considering the specific character of orientalism and oriental studies in Italy, while briefly discussing the issue of female travel literature. Finally, they present the essays contained in the volume, suggesting different ways of reading them

Radiative corrections to decay amplitudes in lattice QCD

The precision of lattice QCD computations of many quantities has reached such a precision that isospin-breaking corrections, including electromagnetism, must be included if further progress is to be made in extracting fundamental information, such as the values of Cabibbo-Kobayashi-Maskawa matrix elements, from experimental measurements. We discuss the framework for including radiative corrections in leptonic and semileptonic decays of hadrons, including the treatment of infrared divergences. We briefly review isospin breaking in leptonic decays and present the first numerical results for the ratio $\Gamma(K_{\mu2})/\Gamma(\pi_{\mu2})$ in which these corrections have been included. We also discuss the additional theoretical issues which arise when including electromagnetic corrections to semileptonic decays, such as $K_{\ell3}$ decays. The separate definition of strong isospin-breaking effects and those due to electromagnetism requires a convention. We define and advocate conventions based on hadronic schemes, in which a chosen set of hadronic quantities, hadronic masses for example, are set equal in QCD and in QCD+QED. This is in contrast with schemes which have been largely used to date, in which the renormalised $\alpha_s(\mu)$ and quark masses are set equal in QCD and in QCD+QED in some renormalisation scheme and at some scale $\mu$.Comment: Presented at the 36th Annual International Symposium on Lattice Field Theory (Lattice2018), Michigan State University, July 22nd - 28th 201