4,688 research outputs found

    Unbinned test of time-dependent signals in real-time neutrino oscillation experiments

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    Real-time neutrino oscillation experiments such as Super-Kamiokande (SK), the Sudbury Neutrino Observatory (SNO), the Kamioka Liquid scintillator Anti-Neutrino Detector (KamLAND), and Borexino, can detect time variations of the neutrino signal, provided that the statistics is sufficiently high. We quantify this statement by means of a simple unbinned test, whose sensitivity depends on the variance of the signal in the time domain, as well as on the total number of signal and background events. The test allows a unified discussion of the statistical uncertainties affecting current or future measurements of eccentricity-induced variations and of day-night asymmetries (in SK, SNO, and Borexino), as well as of reactor power variations (in KamLAND).Comment: 17 pages, including 3 figure

    Addendum to: Model-dependent and -independent implications of the first Sudbury Neutrino Observatory results

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    In the light of recent experimental and theoretical improvements, we review our previous model-independent comparison [hep-ph/0106247] of the Super-Kamiokande (SK) and Sudbury Neutrino Observatory (SNO) solar neutrino event rates, including updated values for the ``equalized'' SK datum and for the reference Standard Solar Model (SSM) B neutrino flux. We find that the joint SK+SNO evidence for active neutrino flavor transitions is confirmed at the level of 3.3 standard deviations, independently of possible transitions to sterile states. Barring sterile neutrinos, we estimate the 3-sigma range for the 8^8B neutrino flux (normalized to SSM) as f_B=0.96 +0.54-0.55. Accordingly, the 3-sigma range for the energy-averaged nu_e survival probability is found to be = 0.31 +0.55-0.16, independently of the functional form of P_ee. An increase of the reference nu_e + d --> p + p + e cross section by ~3%, as suggested by recent theoretical calculations, would slightly shift the central values of f_B and of to ~1.00 and ~0.29, respectively, and would strengthen the model-independent evidence for nu_e transitions into active states at the level of ~3.6 sigma.Comment: 6 pages + 2 figures. Addendum to hep-ph/010624

    Global analysis of three-flavor neutrino masses and mixings

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    We present a comprehensive phenomenological analysis of a vast amount of data from neutrino flavor oscillation and non-oscillation searches, performed within the standard scenario with three massive and mixed neutrinos, and with particular attention to subleading effects. The detailed results discussed in this review represent a state-of-the-art, accurate and up-to-date (as of August 2005) estimate of the three-neutrino mass-mixing parameters.Comment: Final version (including a new Appendix), to be published in "Progress in Particle and Nuclear Physics". Higher-resolution pdf file and eps figures can be download from http://www.ba.infn.it/~now2004/PPNP_review

    Neutrino masses and mixings: Status of known and unknown 3ν3\nu parameters

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    Within the standard 3nu mass-mixing framework, we present an up-to-date global analysis of neutrino oscillation data (as of January 2016), including the latest available results from experiments with atmospheric neutrinos (Super-Kamiokande and IceCube DeepCore), at accelerators (first T2K anti-nu and NOvA nu runs in both appearance and disappearance mode), and at short-baseline reactors (Daya Bay and RENO far/near spectral ratios), as well as a reanalysis of older KamLAND data in the light of the "bump" feature recently observed in reactor spectra. We discuss improved constraints on the five known oscillation parameters (delta m^2, |Delta m^2|, sin^2theta_12, sin^2theta_13, sin^2theta_23), and the status of the three remaining unknown parameters: the mass hierarchy, the theta_23 octant, and the possible CP-violating phase delta. With respect to previous global fits, we find that the reanalysis of KamLAND data induces a slight decrease of both delta m^2 and sin^2theta_12, while the latest accelerator and atmospheric data induce a slight increase of |Delta m^2|. Concerning the unknown parameters, we confirm the previous intriguing preference for negative values of sin(delta) [with best-fit values around sin(delta) ~ -0.9], but we find no statistically significant indication about the theta_23 octant or the mass hierarchy (normal or inverted). Assuming an alternative (so-called LEM) analysis of NOvA data, some delta ranges can be excluded at >3 sigma, and the normal mass hierarchy appears to be slightly favored at 90% C.L. We also describe in detail the covariances of selected pairs of oscillation parameters. Finally, we briefly discuss the implications of the above results on the three non-oscillation observables sensitive to the (unknown) absolute nu mass scale: the sum of nu masses, the effective nu_e mass, and the effective Majorana mass.Comment: 15 pages, 9 figures, 2 tables. Invited contribution prepared for the Nuclear Physics B Special Issue on "Neutrino Oscillations" celebrating the Nobel Prize in Physics 201

    Atmospheric, Solar, and CHOOZ neutrinos: a global three generation analysis

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    We perform a global three generation analysis of the current solar and atmospheric evidence in favor of neutrino oscillations. We also include the negative results coming from CHOOZ to constrain the nu_e mixing. We study the zones of mass-mixing oscillations parameters compatible with all the data. It is shown that almost pure nu_mu nu_tau oscillations are required to explain the atmospheric neutrino anomaly and almost pure nu_1 nu_2 oscillations to account for the solar neutrino deficit.Comment: 4 pages, talk given at 36th Rencontres de Moriond: Electroweak Interactions and Unified Theories, Les Arcs, France, 10-17 Mar 200

    Neutrino mass and mixing parameters: A short review

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    We present a brief review of the current status of neutrino mass and mixing parameters, based on a comprehensive phenomenological analysis of neutrino oscillation and non-oscillation searches, within the standard three-neutrino mixing framework.Comment: 11 pages, including 7 figures. Presented at the 40th Rencontres de Moriond on Electroweak Interactions and Unified Theories, La Thuile, Aosta Valley, Italy, 5-12 Mar 200

    Status of three-neutrino oscillation parameters, circa 2013

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    The standard three-neutrino (3nu) oscillation framework is being increasingly refined by results coming from different sets of experiments, using neutrinos from solar, atmospheric, accelerator and reactor sources. At present, each of the known oscillation parameters [the two squared mass gaps (delta m^2, Delta m^2) and the three mixing angles (theta_12}, theta_13, theta_23)] is dominantly determined by a single class of experiments. Conversely, the unknown parameters [the mass hierarchy, the theta_23 octant and the CP-violating phase delta] can be currently constrained only through a combined analysis of various (eventually all) classes of experiments. In the light of recent new results coming from reactor and accelerator experiments, and of their interplay with solar and atmospheric data, we update the estimated N-sigma ranges of the known 3nu parameters, and revisit the status of the unknown ones. Concerning the hierarchy, no significant difference emerges between normal and inverted mass ordering. A slight overall preference is found for theta_23 in the first octant and for nonzero CP violation with sin delta < 0; however, for both parameters, such preference exceeds 1 sigma only for normal hierarchy. We also discuss the correlations and stability of the oscillation parameters within different combinations of data sets.Comment: Updated and revised version, accepted for publication in PRD. The analysis includes the latest (March 2014) T2K disappearance data: all the figures and the numerical results have been updated, and parts of the text have been revised accordingl

    Internal Power Recovery Systems for Cryogenic Cooling Plants: Secondary Compressor Development

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    Abstract Refrigeration systems consume a relevant amount of electrical power worldwide. For this reason, in the last decades, several energy saving techniques have been proposed to reduce the power demand of such plants. The present paper deals with the development of an innovative internal power recovery system for industrial cryogenic cooling plants. Such an innovative system consists in a Compressor-Expander Group (CEG) for internal power recovery. In particular, the paper is focused on the development of the CEG compressor, which has to pre-compress the refrigerant main flow before the fluid enters the main compressor. The machine has been re-designed, modifying a centrifugal compressor for automotive turbocharging. To verify the performance and suggest improvements, a numerical fluid dynamic model has been set up and the commercial Ansys-CFX software has been utilized to perform steady-state 3D simulations. Expected performance of the secondary compressor are presented and discussed in this paper

    Molecular Approach to Cutaneous Squamous Cell Carcinoma: From Pathways to Therapy

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    Cutaneous squamous cell carcinoma (cSCC) represents the second most frequent skin cancer,recently showing a rapid increase in incidence worldwide, with around &gt;1 million cases/year in theUnited States and 2500 deaths [1] [...]
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