47 research outputs found

    Modeling of GERDA Phase II data

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    The GERmanium Detector Array (Gerda) experiment at the Gran Sasso underground laboratory (LNGS) of INFN is searching for neutrinoless double-beta (0\u3bd\u3b2\u3b2) decay of 76Ge. The technological challenge of Gerda is to operate in a \u201cbackground-free\u201d regime in the region of interest (ROI) after analysis cuts for the full 100 kg\ub7yr target exposure of the experiment. A careful modeling and decomposition of the full-range energy spectrum is essential to predict the shape and composition of events in the ROI around Q\u3b2\u3b2 for the 0\u3bd\u3b2\u3b2 search, to extract a precise measurement of the half-life of the double-beta decay mode with neutrinos (2\u3bd\u3b2\u3b2) and in order to identify the location of residual impurities. The latter will permit future experiments to build strategies in order to further lower the background and achieve even better sensitivities. In this article the background decomposition prior to analysis cuts is presented for Gerda Phase II. The background model fit yields a flat spectrum in the ROI with a background index (BI) of 16.04 120.85+0.78\ub710 123 cts/(keV\ub7kg\ub7yr) for the enriched BEGe data set and 14.68 120.52+0.47\ub710 123 cts/(keV\ub7kg\ub7yr) for the enriched coaxial data set. These values are similar to the one of Phase I despite a much larger number of detectors and hence radioactive hardware components

    Search for exotic physics in double-β decays with GERDA Phase II

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    A search for Beyond the Standard Model double-β\beta decay modes of76^{76}Ge has been performed with data collected during the Phase II of theGERmanium Detector Array (GERDA) experiment, located at Laboratori Nazionalidel Gran Sasso of INFN (Italy). Improved limits on the decays involvingMajorons have been obtained, compared to previous experiments with 76^{76}Ge,with half-life values on the order of 1023^{23} yr. For the first time with76^{76}Ge, limits on Lorentz invariance violation effects in double-β\betadecay have been obtained. The isotropic coefficienta˚of(3)\mathring{a}_\text{of}^{(3)}, which embeds Lorentz violation indouble-β\beta decay, has been constrained at the order of 10610^{-6} GeV. Wealso set the first experimental limits on the search for light exotic fermionsin double-β\beta decay, including sterile neutrinos.<br

    Feint Lines: Notes on the Creation of a Skateboard Choreography

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    Magnetic fields on a range of scales play a large role in the ecosystems of galaxies, both in the galactic disk and in the extended layers of gas away from the plane. Observing magnetic field strength, structure and orientation is complex, and necessarily indirect. Observational data of magnetic fields in the halo of the Milky Way are scarce, and non-conclusive about the large-scale structure of the field. In external galaxies, various large-scale configurations of magnetic fields are measured, but many uncertainties about exact configurations and their origin remain. There is a strong interaction between magnetic fields and other components in the interstellar medium such as ionized and neutral gas and cosmic rays. The energy densities of these components are comparable on large scales, indicating that magnetic fields are not passive tracers but that magnetic field feedback on the other interstellar medium components needs to be taken into account.Comment: 13 pages, 7 figures. Accepted in Space Science Review

    The Physics of the B Factories

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    Nanophononics: state of the art and perspectives

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    Palliation of malignant rectal obstruction with self-expanding metal stents

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    BACKGROUND: Surgical management of patients with metastatic or recurrent rectal cancer remains controversial. Self-expanding metal stents are increasingly used for palliative treatment of advanced tumors, although long-term results are not yet available. METHODS: Between 1996 and 2003, 521 patients underwent surgery for rectal neoplasms. In the same time period, self-expanding metal stents were used for palliation of 34 patients with malignant rectal obstruction and incurable disease. The outcome of the patients was analyzed retrospectively. RESULTS: Rectal stents were successfully placed in 33 of 34 patients (97%) without major complications. Early failure occurred in 7 patients (21%) because of stent migration, pain, or incontinence. Long-term success with a mean patency of 5.3 months was observed in 26 patients (79%), but restenting was required in 2 patients. Despite the initial success of stenting, a colostomy was created in 2 other patients after 3.4 months and 9.2 months because of incontinence and rectovesical fistula. Overall, 6 of 33 patients (18%) underwent palliative surgery because of early complications (n = 4) or long-term failure of stent treatment (n = 2). CONCLUSIONS: Self-expanding metal stents are useful to avoid a colostomy in selected patients with incurable rectal cancer and limited life expectancy. Nonetheless, a considerable number (18%) of patients will require surgical palliation because of failure of stent treatment

    Successful hybridization between non‐congeneric parrots in a small introduced population

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    Introduced organisms have to overcome several obstacles, including the scarcity of conspecific mates, before becoming successfully established. We recorded inter-specific mating in non-native areas (Spain) that involved Orange-winged Amazons Amazona amazónica with three non-congeneric parrot species: Scaly-headed ParrotPionus maximiliani, Rose-ringed Parakeet Psittacula krameriand Monk Parakeet Myiopsitta monachus. Ratherthan mating with parakeets, a male Orange-wingedAmazon successfully bred with a female Scaly-headed Parrot, raising hybrid offspring duringfive consecutive years and thus increasing the initial population size fromfive to 12 individuals in 9 years. Non-congenerichy bridization seems to be extremely rare in wild parrotsand, in this case, it may facilitate the successful establishment of a small introduced population in Tenerife, Spain.This research was supported by the Severo Ochoa Program (SVP-2014-068732) and Action COST ES1304 (Parrot Net).Peer reviewe
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