Neutrino Decay and Atmospheric Neutrinos

We reconsider neutrino decay as an explanation for atmospheric neutrino observations. We show that if the mass-difference relevant to the two mixed states \nu_\mu and \nu_\tau is very small (< 10^{-4} eV^2), then a very good fit to the observations can be obtained with decay of a component of \nu_\mu to a sterile neutrino and a Majoron. We discuss how the K2K and MINOS long-baseline experiments can distinguish the decay and oscillation scenarios.Comment: 9 pages, Revtex, uses epsf.sty, 3 postscript figures. Additions and corrections to references, minor changes in the text and to some number

The TNG Near Infrared Camera Spectrometer

NICS (acronym for Near Infrared Camera Spectrometer) is the near-infrared cooled camera-spectrometer that has been developed by the Arcetri Infrared Group at the Arcetri Astrophysical Observatory, in collaboration with the CAISMI-CNR for the TNG (the Italian National Telescope Galileo at La Palma, Canary Islands, Spain). As NICS is in its scientific commissioning phase, we report its observing capabilities in the near-infrared bands at the TNG, along with the measured performance and the limiting magnitudes. We also describe some technical details of the project, such as cryogenics, mechanics, and the system which executes data acquisition and control, along with the related software.Comment: 7 pages, 5 figures, compiled with A&A macros. A&A in pres

Observables sensitive to absolute neutrino masses: A reappraisal after WMAP-3y and first MINOS results

In the light of recent neutrino oscillation and non-oscillation data, we revisit the phenomenological constraints applicable to three observables sensitive to absolute neutrino masses: The effective neutrino mass in single beta decay (m_beta); the effective Majorana neutrino mass in neutrinoless double beta decay (m_2beta); and the sum of neutrino masses in cosmology (Sigma). In particular, we include the constraints coming from the first Main Injector Neutrino Oscillation Search (MINOS) data and from the Wilkinson Microwave Anisotropy Probe (WMAP) three-year (3y) data, as well as other relevant cosmological data and priors. We find that the largest neutrino squared mass difference is determined with a 15% accuracy (at 2-sigma) after adding MINOS to world data. We also find upper bounds on the sum of neutrino masses Sigma ranging from ~2 eV (WMAP-3y data only) to ~0.2 eV (all cosmological data) at 2-sigma, in agreement with previous studies. In addition, we discuss the connection of such bounds with those placed on the matter power spectrum normalization parameter sigma_8. We show how the partial degeneracy between Sigma and sigma_8 in WMAP-3y data is broken by adding further cosmological data, and how the overall preference of such data for relatively high values of sigma_8 pushes the upper bound of Sigma in the sub-eV range. Finally, for various combination of data sets, we revisit the (in)compatibility between current Sigma and m_2beta constraints (and claims), and derive quantitative predictions for future single and double beta decay experiments.Comment: 18 pages, including 7 figure

Geo-neutrinos: A systematic approach to uncertainties and correlations

Geo-neutrinos emitted by heat-producing elements (U, Th and K) represent a unique probe of the Earth interior. The characterization of their fluxes is subject, however, to rather large and highly correlated uncertainties. The geochemical covariance of the U, Th and K abundances in various Earth reservoirs induces positive correlations among the associated geo-neutrino fluxes, and between these and the radiogenic heat. Mass-balance constraints in the Bulk Silicate Earth (BSE) tend instead to anti-correlate the radiogenic element abundances in complementary reservoirs. Experimental geo-neutrino observables may be further (anti)correlated by instrumental effects. In this context, we propose a systematic approach to covariance matrices, based on the fact that all the relevant geo-neutrino observables and constraints can be expressed as linear functions of the U, Th and K abundances in the Earth's reservoirs (with relatively well-known coefficients). We briefly discuss here the construction of a tentative "geo-neutrino source model" (GNSM) for the U, Th, and K abundances in the main Earth reservoirs, based on selected geophysical and geochemical data and models (when available), on plausible hypotheses (when possible), and admittedly on arbitrary assumptions (when unavoidable). We use then the GNSM to make predictions about several experiments ("forward approach"), and to show how future data can constrain - a posteriori - the error matrix of the model itself ("backward approach"). The method may provide a useful statistical framework for evaluating the impact and the global consistency of prospective geo-neutrino measurements and Earth models.Comment: 17 pages, including 4 figures. To appear on "Earth, Moon, and Planets," Special Issue on "Neutrino Geophysics," Proceedings of Neutrino Science 2005 (Honolulu, Hawaii, Dec. 2005

Super-Kamiokande data and atmospheric neutrino decay

Neutrino decay has been proposed as a possible solution to the atmospheric neutrino anomaly, in the light of the recent data from the Super-Kamiokande experiment. We investigate this hypothesis by means of a quantitative analysis of the zenith angle distributions of neutrino events in Super-Kamiokande, including the latest (45 kTy) data. We find that the neutrino decay hypothesis fails to reproduce the observed distributions of muons.Comment: 6 pages (RevTeX) + 2 figures (Postscript

Earthquake-Related Signals in Central Italy Detected by Hydrogeochemical and Satellite Techniques

Central Apennines are one of the highest seismic risk regions in Italy. A number of energetic events ((Formula presented.) &gt; 5) struck the region during the period 2004–2017, killing several hundreds of people (e.g., 294 casualties associated with the August 24th, 2016, (Formula presented.) 6.0 event of Amatrice). These earthquakes impacted piezometric levels, springs discharges, and groundwater chemistry across a large area, even at distances of dozens of kilometers from the epicenters. Here we present a multidisciplinary dataset based on hydrogeochemical and satellite observations associated with the seismic events that occurred in Central Italy during the period 2004–2017, which combines information derived from the application of groundwater monitoring and satellite techniques. Groundwater monitoring techniques allowed for the detection of hydrogeochemical anomalies in spring and well waters (14 water sampling points in total, with 22 variations larger than (Formula presented.)), while satellite techniques were applied to detect time-space variations in ground thermal emissions. We detected two significant, almost synchronous, anomalies in 2009 and 2016–2017 with both techniques, and we tentatively correlated them to crustal deformation processes. Part of the observed signals were detected before mainshocks, and they appear to be related to aseismic slip or to seismic slip eventually induced by minor fluctuations in seismicity. We argue that the combination of two factors, i.e., the shallow depth of local earthquakes and the concurrent deepening of groundwater circulation paths to several km depth, allow for the recording of variations in the stress field by geofluids released at the surface

Crustal blocks and seismicity in the Central Apennines of Italy

Kinematics and geodynamics of crustal-block structures separated by compliant zones with viscoelastic rheology play an important role in defining the conditions for many deformation events such as ordinary seismic ruptures, silent and slow earthquakes and aseismic fault creep phenomena. New seismological data from the Latium-Abruzzi carbonatic platform of central Italy fit a block-tectonic modelling previously proposed for this area on the basis of structural and paleomagnetic evidences

Ribosomal stress activates eEF2K-eEF2 pathway causing translation elongation inhibition and recruitment of Terminal Oligopyrimidine (TOP) mRNAs on polysomes

The synthesis of adequate amounts of ribosomes is an essential task for the cell. It is therefore not surprising that regulatory circuits exist to organize the synthesis of ribosomal components. It has been shown that defect in ribosome biogenesis (ribosomal stress) induces apoptosis or cell cycle arrest through activation of the tumor suppressor p53. This mechanism is thought to be implicated in the pathophysiology of a group of genetic diseases such as Diamond Blackfan Anemia which are called ribosomopathies. We have identified an additional response to ribosomal stress that includes the activation of eukaryotic translation elongation factor 2 kinase with a consequent inhibition of translation elongation. This leads to a translational reprogramming in the cell that involves the structurally defined group of messengers called terminal oligopyrimidine (TOP) mRNAs which encode ribosomal proteins and translation factors. In fact, while general protein synthesis is decreased by the impairment of elongation, TOP mRNAs are recruited on polysomes causing a relative increase in the synthesis of TOP mRNA-encoded proteins compared to other proteins. Therefore, in response to ribosomal stress, there is a change in the translation pattern of the cell which may help restore a sufficient level of ribosomes