Status and potentialities of the JUNO experiment

One of the main open issues of neutrino physics is the determination of the mass hierarchy, discriminating between the two possible ordering of the mass eigenvalues, known as Normal and Inverted Hierarchies. The solution of this puzzle would have a significant impact both on elementary particle physics and astrophysics. A possible way to investigate the problem is the study, with medium baseline reactor antineutrinos, of the mass dependent corrections to inverse $\beta$ decays. This is the idea pursued by JUNO, a multipurpose underground liquid scintillator experiment that will start data taking in very few years from now. The main characteristics and the status of the experiment are discussed here, together with its rich physics program. We focus in particular on the potentiality for mass hierarchy determination, the main goal of the experiment, on the oscillation parameters accurate measurements and on the supernova and solar neutrinos and geoneutrino studies.Comment: Invited talk given, on behalf of the JUNO Collaboration, by Vito Antonelli at the XVII International Workshop on Neutrino Telescopes (Venice, 13-17 March 2017

The flat X-ray spectrum of the LINER NGC1052

We report on ROSAT and ASCA observations of the LINER NGC1052, which is the first one where broad optical lines in polarized light have been observed. The 2-10 keV spectrum is very flat, with an observed photon index (Gamma) ~0.1. A model where a nuclear source is - partly or totally - obscured by a screen of matter with column density ~10^23 atom/cm/cm is the most convincing explanation for the observed flatness. This agrees with the hypothesis that the LINERs are a population of low-luminosity AGN, to which the Seyfert unification scenario applies. The intrinsic spectral index is still rather flat (1.0-1.4), as observed in a few type-2 Seyferts so far or predicted if the accretion occurs in an advection-dominated flow.Comment: 5 pages, Latex, 2 Postscript figures, accepted for publication in MNRA

Neutrino oscillations and Lorentz Invariance Violation in a Finslerian Geometrical model

Neutrino oscillations are one of the first evidences of physics beyond the Standard Model (SM). Since Lorentz Invariance is a fundamental symmetry of the SM, recently also neutrino physics has been explored to verify the eventual modification of this symmetry and its potential magnitude. In this work we study the consequences of the introduction of Lorentz Invariance Violation (LIV) in the high energy neutrinos propagation and evaluate the impact of this eventual violation on the oscillation predictions. An effective theory explaining these physical effects is introduced via Modified Dispersion Relations. This approach, originally introduced by Coleman and Glashow, corresponds in our model to a modification of the special relativity geometry. Moreover, the generalization of this perspective leads to the introduction of a maximum attainable velocity which is specific of the particle. This can be formalized in Finsler geometry, a more general theory of space-time. In the present paper the impact of this kind of LIV on neutrino phenomenology is studied, in particular by analyzing the corrections introduced in neutrino oscillation probabilities for different values of neutrino energies and baselines of experimental interest. The possibility of further improving the present constraints on CPT-even LIV coefficients by means of our analysis is also discussed.Comment: Accepted for publication with minor revisions, will appear on European Physics Journal

Solar Neutrinos

The study of solar neutrinos has given since ever a fundamental contribution both to astroparticle and to elementary particle physics, offering an ideal test of solar models and offering at the same time relevant indications on the fundamental interactions among particles. After reviewing the striking results of the last two decades, which were determinant to solve the long standing solar neutrino puzzle and refine the Standard Solar Model, we focus our attention on the more recent results in this field and on the experiments presently running or planned for the near future. The main focus at the moment is to improve the knowledge of the mass and mixing pattern and especially to study in detail the lowest energy part of the spectrum, which represents most of solar neutrino spectrum but is still a partially unexplored realm. We discuss this research project and the way in which present and future experiments could contribute to make the theoretical framemork more complete and stable, understanding the origin of some "anomalies" that seem to emerge from the data and contributing to answer some present questions, like the exact mechanism of the vacuum to matter transition and the solution of the so called solar metallicity problem.Comment: 51 pages, to be published in Special Issue on Neutrino Physics, Advances in High Energy Physics Hindawi Publishing Corporation 201

Dose of colistin. a work in progress?

We thank Rashid and colleagues [1] and Honoré and colleagues [2] for their comments regarding our article on risk factors for acute kidney injury in pa- tients receiving colistin or other nephrotoxic antimi- crobials [3]. It is correct that we did not specifically report urine output in the text, but it was obviously included in the RIFLE (Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease) criteria reported in Table two [3]

Analysis of X-ray flares in GRBs

We present a detailed study of the spectral and temporal properties of the X-ray flares emission of several GRBs. We select a sample of GRBs which X-ray light curve exhibits large amplitude variations with several rebrightenings superposed on the underlying three-segment broken powerlaw that is often seen in Swift GRBs. We try to understand the origin of these fluctuations giving some diagnostic in order to discriminate between refreshed shocks and late internal shocks. For some bursts our time-resolved spectral analysis supports the interpretation of a long-lived central engine, with rebrightenings consistent with energy injection in refreshed shocks as slower shells generated in the central engine prompt phase catch up with the afterglow shock at later times.Comment: 9 pages, 3 figures. Invited talk at the Swift-Venice 2006 meeting to be published by "Il Nuovo Cimento

Extinction properties of the X-ray bright/optically faint afterglow of GRB 020405

We present an optical-to-X-ray spectral analysis of the afterglow of GRB 020405. The optical spectral energy distribution not corrected for the extragalactic extinction is significantly below the X-ray extrapolation of the single powerlaw spectral model suggested by multiwavelength studies. We investigate whether considerable extinction could explain the observed spectral ``mismatch'' by testing several types of extinction curves. For the first time we test extinction curves computed with time-dependent numerical simulations of dust grains destruction by the burst radiation. We find that an extinction law weakly depen dent on wavelength can reconcile the unabsorbed optical and X-ray data with the expected synchrotron spectrum. A gray extinction law can be provided by a dust grain size distribution biased toward large grains.Comment: 6 pages, 5 figures, accepted for publication on A&

Food Habits of Dicamptodon Ensatus and Associated Fish Species of Maratta Creek, Washington

Three cold-blooded vertebrates, Dicamptodon ensatus, Cottus tenuis, and Salmo gairdneri were investigated as to food habits for a period of one year. The existence of competition between these animals for food was determined by means of stomach analysis. The results were compared relative to each vertebrate and the bottom fauna procurred from the stream. It was shown that the food habits of D. ensatus and S. gairdneri were diverse enough to warrant partial exclusion on the basis of food. C. tenuis demonstrated selectivity and was shown to be under competitive stress from the other two species