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Milan, Italy

The INFN Grid project was an initiative of the Istituto Nazionale di Fisica Nucleare —Italy's National Institute for Nuclear Physics—for grid computing. Its goal was to develop and deploy grid middleware services to allow INFN's various user communities to transparently and securely share the computing and storage resources together with applications and technical facilities for scientific collaborations.With the beginning of the European Grid Infrastructure project in 2010, the activities of INFN Grid were consolidated into the Italian Grid Infrastructure which operates as a European joint research unit formally supported by the Italian Ministry for University and Research and the European Commission. Wikipedia.

Shao G.-Y.,National Institute of Nuclear Physics, Italy
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2011

The Poyakov-Nambu-Jona-Lasinio (PNJL) model was developed recently, which includes both the chiral dynamics and (de)confinement effect and gives a good description of lattice QCD data. In this study we use the PNJL model to describe the quark phase, and first use it to study the evolution of proto-neutron star (PNS) with a hadron-quark phase transition. Along the line of a PNS evolution, we take several snapshots of PNS profiles, presenting the fractions of different species, the equations of state (EOS), and the mass-radius relations at different stages. The calculation shows the mixed phase may exist during the whole evolving process, and the onset density of quark phase decreases with the radiation of neutrinos in the heating stage. In the cooling stage, the EOS of the mixed phase softens and the center density increases. In this process a part of nuclear matter transforms to quark matter, which may lead to a PNS collapsing into a black hole. © 2011 Elsevier B.V.

Tomassetti N.,National Institute of Nuclear Physics, Italy
Astrophysical Journal Letters | Year: 2012

Recent data from ATIC, CREAM, and PAMELA indicate that the cosmic-ray energy spectra of protons and nuclei exhibit a remarkable hardening at energies above 100GeVnucleon-1. We propose that the hardening is an interstellar propagation effect that originates from a spatial change of the cosmic-ray transport properties in different regions of the Galaxy. The key hypothesis is that the diffusion coefficient is not separable into energy and space variables as usually assumed. Under this scenario, we can reproduce the observational data well. Our model has several implications for cosmic-ray acceleration/propagation physics and can be tested by ongoing experiments such as the Alpha Magnetic Spectrometer or Fermi-LAT. © 2012. The American Astronomical Society. All rights reserved..

Colonna M.,National Institute of Nuclear Physics, Italy
Physical Review Letters | Year: 2013

Within a dynamical description of nuclear fragmentation, based on the liquid-gas phase transition scenario, we explore the relation between neutron-proton density fluctuations and nuclear symmetry energy. We show that, along the fragmentation path, isovector fluctuations follow the evolution of the local density and approach an equilibrium value connected to the local symmetry energy. Higher-density regions are characterized by smaller average asymmetry and narrower isotopic distributions. This dynamical analysis points out that fragment final state isospin fluctuations can probe the symmetry energy of the density domains from which fragments originate. © 2013 American Physical Society.

Berezinsky V.,National Institute of Nuclear Physics, Italy
Astroparticle Physics | Year: 2014

The signatures of UHE proton propagation through CMB radiation are pair-production dip and GZK cutoff. The visible manifestations of these two spectral features are ankle, which is intrinsic part of the dip, beginning of GZK cutoff in the differential spectrum and E1/2 in integral spectrum. Observed practically in all experiments since 1963, the ankle is usually interpreted as a feature caused by transition from galactic to extragalactic cosmic rays. Using the mass composition measured by HiRes, Telescope Array and Auger detectors at energy (1-3) EeV, calculated anisotropy of galactic cosmic rays at these energies, and the elongation curves we strongly argue against the interpretation of the ankle given above. The transition must occur at lower energy, most probably at the second knee as the dip model predicts. The other prediction of the dip model, the shape of the dip, is well confirmed by HiRes, Telescope Array (TA), AGASA and Yakutsk detectors, and, after recalibration of energies, by Auger detector. Predicted beginning of GZK cutoff and E1/2 agree well with HiRes and TA data. However, directly measured mass composition remains a puzzle. While HiRes and TA detectors observe the proton-dominated mass composition, as required by the dip model, the data of Auger detector strongly evidence for nuclei mass composition becoming progressively heavier at energy higher than 4 EeV and reaching Iron at energy about 35 EeV. The Auger-based scenario is consistent with another interpretation of the ankle at energy Ea≈4 EeV as transition from extragalactic protons to extragalactic nuclei. The heavy-nuclei dominance at higher energies may be provided by low-energy of acceleration for protons Epmax∼4 EeV and rigidity-dependent EAmax=ZEpmax for nuclei. The highest energy suppression may be explained as nuclei-photodisintegration cutoff. © 2013 Elsevier B.V. All rights reserved.

Giunti C.,National Institute of Nuclear Physics, Italy | Studenikin A.,Moscow State University
Reviews of Modern Physics | Year: 2015

A review is given of the theory and phenomenology of neutrino electromagnetic interactions, which provide powerful tools to probe the physics beyond the standard model. After a derivation of the general structure of the electromagnetic interactions of Dirac and Majorana neutrinos in the one-photon approximation, the effects of neutrino electromagnetic interactions in terrestrial experiments and in astrophysical environments are discussed. The experimental bounds on neutrino electromagnetic properties are presented and the predictions of theories beyond the standard model are confronted. © 2015 American Physical Society.

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