953 research outputs found

    Texture zeros and hierarchical masses from flavour (mis)alignment

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    We introduce an unconventional interpretation of the fermion mass matrix elements. As the full rotational freedom of the gauge-kinetic terms renders a set of infinite bases called weak bases, basis-dependent structures as mass matrices are unphysical. Matrix invariants, on the other hand, provide a set of basis-independent objects which are of more relevance. We employ one of these invariants to give a new parametrization of the mass matrices. By virtue of it, one gains control over its implicit implications on several mass matrix structures. The key element is the trace invariant which resembles the equation of a hypersphere with a radius equal to the Frobenius norm of the mass matrix. With the concepts of alignment or misalignment we can identify texture zeros with certain alignments whereas Froggatt-Nielsen structures in the matrix elements are governed by misalignment. This method allows further insights of traditional approaches to the underlying flavour geometry.Comment: 27 pages; v2 matches version accepted by NPB, discussion on Dirac CP phase for neutrinos adde

    Vibrating soap films: An analog for quantum chaos on billiards

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    We present an experimental setup based on the normal modes of vibrating soap films which shows quantum features of integrable and chaotic billiards. In particular, we obtain the so-called scars -narrow linear regions with high probability along classical periodic orbits- for the classically chaotic billiards. We show that these scars are also visible at low frequencies. Finally, we suggest some applications of our experimental setup in other related two-dimensional wave phenomena.Comment: 5 pages, 7 figures. Better Postscript figures available on reques

    Land Surface Processes Analysis Using Sentinel-3 OLCI and Modis Data

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    This communication describes the optical processing chain to use Sentinel-3 OLCI and MODIS data as part of the ESA funded Synergy project of the Scientific Exploitation of Sentinel Missions (SEOM) component of the EO Envelope programme. One of the goals of the project is to use Data Assimilation techniques to produce land surface products combining the data from Sentinels-2 and 3. Some of the derived products are the OLCI atmospherically corrected data that can be used to generate a spectral BRDF product from OLCI and MODIS, broadband albedo and different vegetation parameters. The project also implements a series of efficiency improvements to the algorithms to speed up the processing. The demonstrator product uses one year of OLCI and MODIS data (2017)

    A new derivation of the Hubble constant from γ\gamma-ray attenuation using improved optical depths for the Fermi and CTA era

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    We present γ\gamma-ray optical-depth calculations from a recently published extragalactic background light (EBL) model built from multiwavelength galaxy data from the Hubble Space Telescope Cosmic Assembly Near-Infrared Deep Extragalactic Legacy Survey (HST/CANDELS). CANDELS gathers one of the deepest and most complete observations of stellar and dust emissions in galaxies. This model resulted in a robust derivation of the evolving EBL spectral energy distribution up to z∼6z\sim 6, including the far-infrared peak. Therefore, the optical depths derived from this model will be useful for determining the attenuation of γ\gamma-ray photons coming from high-redshift sources, such as those detected by the Large Area Telescope on board the Fermi Gamma-ray Space Telescope, and for multi-TeV photons that will be detected from nearby sources by the future Cherenkov Telescope Array. From these newly calculated optical depths, we derive the cosmic γ\gamma-ray horizon and also measure the expansion rate and matter content of the Universe including an assessment of the impact of the EBL uncertainties. We find H0=61.9H_{0}=61.9 −2.4+2.9^{+2.9}_{-2.4} km s−1^{-1} Mpc−1^{-1} when fixing Ωm=0.32\Omega_{m}=0.32, and H0=65.6H_{0}=65.6 −5.0+5.6^{+5.6}_{-5.0} km s−1^{-1} Mpc−1^{-1} and Ωm=0.19±0.07\Omega_{m}=0.19\pm 0.07, when exploring these two parameters simultaneously.Comment: 11 pages, 8 figures, 1 tables; Accepted by MNRA
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