1,813 research outputs found

    Genomic analysis reveals hidden biodiversity within colugos, the sister group to primates

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    Colugos are among the most poorly studied mammals despite their centrality to resolving supraordinal primate relationships. Two described species of these gliding mammals are the sole living members of the order Dermoptera, distributed throughout Southeast Asia. We generated a draft genome sequence for a Sunda colugo and a Philippine colugo reference alignment, and used these to identify colugo-specific genetic changes that were enriched in sensory and musculoskeletal-related genes that likely underlie their nocturnal and gliding adaptations. Phylogenomic analysis and catalogs of rare genomic changes overwhelmingly support the contested hypothesis that colugos are the sister group to primates (Primatomorpha), to the exclusion of treeshrews. We captured ~140 kb of orthologous sequence data from colugo museum specimens sampled across their range and identified large genetic differences between many geographically isolated populations that may result in a >300% increase in the number of recognized colugo species. Our results identify conservation units to mitigate future losses of this enigmatic mammalian order.Victor C. Mason, Gang Li Patrick Minx, Jürgen Schmitz, Gennady Churakov, Liliya Doronina, Amanda D. Melin ... et al

    CUORE-0 results and prospects for the CUORE experiment

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    With 741 kg of TeO2 crystals and an excellent energy resolution of 5 keV (0.2%) at the region of interest, the CUORE (Cryogenic Underground Observatory for Rare Events) experiment aims at searching for neutrinoless double beta decay of 130Te with unprecedented sensitivity. Expected to start data taking in 2015, CUORE is currently in an advanced construction phase at LNGS. CUORE projected neutrinoless double beta decay half-life sensitivity is 1.6E26 y at 1 sigma (9.5E25 y at the 90% confidence level), in five years of live time, corresponding to an upper limit on the effective Majorana mass in the range 40-100 meV (50-130 meV). Further background rejection with auxiliary bolometric detectors could improve CUORE sensitivity and competitiveness of bolometric detectors towards a full analysis of the inverted neutrino mass hierarchy. CUORE-0 was built to test and demonstrate the performance of the upcoming CUORE experiment. It consists of a single CUORE tower (52 TeO2 bolometers of 750 g each, arranged in a 13 floor structure) constructed strictly following CUORE recipes both for materials and assembly procedures. An experiment its own, CUORE-0 is expected to reach a sensitivity to the neutrinoless double beta decay half-life of 130Te around 3E24 y in one year of live time. We present an update of the data, corresponding to an exposure of 18.1 kg y. An analysis of the background indicates that the CUORE performance goal is satisfied while the sensitivity goal is within reach.Comment: 10 pages, 3 figures, to appear in the proceedings of NEUTRINO 2014, 26th International Conference on Neutrino Physics and Astrophysics, 2-7 June 2014, held at Boston, Massachusetts, US

    Search for Neutrinoless Double-Beta Decay of 130^{130}Te with CUORE-0

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    We report the results of a search for neutrinoless double-beta decay in a 9.8~kg\cdotyr exposure of 130^{130}Te using a bolometric detector array, CUORE-0. The characteristic detector energy resolution and background level in the region of interest are 5.1±0.3 keV5.1\pm 0.3{\rm~keV} FWHM and 0.058±0.004(stat.)±0.002(syst.)0.058 \pm 0.004\,(\mathrm{stat.})\pm 0.002\,(\mathrm{syst.})~counts/(keV\cdotkg\cdotyr), respectively. The median 90%~C.L. lower-limit sensitivity of the experiment is 2.9×1024 yr2.9\times 10^{24}~{\rm yr} and surpasses the sensitivity of previous searches. We find no evidence for neutrinoless double-beta decay of 130^{130}Te and place a Bayesian lower bound on the decay half-life, T1/20ν>T^{0\nu}_{1/2}>~2.7×1024 yr 2.7\times 10^{24}~{\rm yr} at 90%~C.L. Combining CUORE-0 data with the 19.75~kg\cdotyr exposure of 130^{130}Te from the Cuoricino experiment we obtain T1/20ν>4.0×1024 yrT^{0\nu}_{1/2} > 4.0\times 10^{24}~\mathrm{yr} at 90%~C.L.~(Bayesian), the most stringent limit to date on this half-life. Using a range of nuclear matrix element estimates we interpret this as a limit on the effective Majorana neutrino mass, mββ<270m_{\beta\beta}< 270 -- 760 meV760~\mathrm{meV}.Comment: 6 pages, 5 figures, updated version as published in PR

    Status of the CUORE and results from the CUORE-0 neutrinoless double beta decay experiments

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    CUORE is a 741 kg array of TeO2 bolometers for the search of neutrinoless double beta decay of 130Te. The detector is being constructed at the Laboratori Nazionali del Gran Sasso, Italy, where it will start taking data in 2015. If the target background of 0.01 counts/keV/kg/y will be reached, in five years of data taking CUORE will have a 1 sigma half life sensitivity of 10E26 y. CUORE-0 is a smaller experiment constructed to test and demonstrate the performances expected for CUORE. The detector is a single tower of 52 CUORE-like bolometers that started taking data in spring 2013. The status and perspectives of CUORE will be discussed, and the first CUORE-0 data will be presented.Comment: 7 pages, 4 figures, to be published in the proceedings of ICHEP 2014, 37th International Conference on High Energy Physics, Valencia (Spain) 2-9 July 201

    Measurement of the Two-Neutrino Double Beta Decay Half-life of 130^{130}Te with the CUORE-0 Experiment

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    We report on the measurement of the two-neutrino double beta decay half-life of 130^{130}Te with the CUORE-0 detector. From an exposure of 33.4 kg\cdoty of TeO2_2, the half-life is determined to be T1/22νT_{1/2}^{2\nu} = [8.2 ±\pm 0.2 (stat.) ±\pm 0.6 (syst.)] ×\times 1020^{20}y. This result is obtained after a detailed reconstruction of the sources responsible for the CUORE-0 counting rate, with a specific study of those contributing to the 130^{130}Te neutrinoless double beta decay region of interest.Comment: Corrected typo in section 9: 3.43E5 Bq/kg should have read 3.43E-5 Bq/k

    Analysis Techniques for the Evaluation of the Neutrinoless Double-Beta Decay Lifetime in 130^{130}Te with CUORE-0

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    We describe in detail the methods used to obtain the lower bound on the lifetime of neutrinoless double-beta (0νββ0\nu\beta\beta) decay in 130^{130}Te and the associated limit on the effective Majorana mass of the neutrino using the CUORE-0 detector. CUORE-0 is a bolometric detector array located at the Laboratori Nazionali del Gran Sasso that was designed to validate the background reduction techniques developed for CUORE, a next-generation experiment scheduled to come online in 2016. CUORE-0 is also a competitive 0νββ0\nu\beta\beta decay search in its own right and functions as a platform to further develop the analysis tools and procedures to be used in CUORE. These include data collection, event selection and processing, as well as an evaluation of signal efficiency. In particular, we describe the amplitude evaluation, thermal gain stabilization, energy calibration methods, and the analysis event selection used to create our final 0νββ0\nu\beta\beta decay search spectrum. We define our high level analysis procedures, with emphasis on the new insights gained and challenges encountered. We outline in detail our fitting methods near the hypothesized 0νββ0\nu\beta\beta decay peak and catalog the main sources of systematic uncertainty. Finally, we derive the 0νββ0\nu\beta\beta decay half-life limits previously reported for CUORE-0, T1/20ν>2.7×1024T^{0\nu}_{1/2}>2.7\times10^{24} yr, and in combination with the Cuoricino limit, T1/20ν>4.0×1024T^{0\nu}_{1/2}>4.0\times10^{24} yr.Comment: 18 pages, 18 figures. (Version 3 reflects only minor changes to the text. Few additional details, no major content changes.

    Material screening and selection for XENON100

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    Results of the extensive radioactivity screening campaign to identify materials for the construction of XENON100 are reported. This Dark Matter search experiment is operated underground at Laboratori Nazionali del Gran Sasso (LNGS), Italy. Several ultra sensitive High Purity Germanium detectors (HPGe) have been used for gamma ray spectrometry. Mass spectrometry has been applied for a few low mass plastic samples. Detailed tables with the radioactive contaminations of all screened samples are presented, together with the implications for XENON100.Comment: 8 pages, 1 figur

    Measurement of the diffractive structure function in deep inelastic scattering at HERA

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    This paper presents an analysis of the inclusive properties of diffractive deep inelastic scattering events produced in epep interactions at HERA. The events are characterised by a rapidity gap between the outgoing proton system and the remaining hadronic system. Inclusive distributions are presented and compared with Monte Carlo models for diffractive processes. The data are consistent with models where the pomeron structure function has a hard and a soft contribution. The diffractive structure function is measured as a function of \xpom, the momentum fraction lost by the proton, of β\beta, the momentum fraction of the struck quark with respect to \xpom, and of Q2Q^2. The \xpom dependence is consistent with the form \xpoma where a = 1.30 ± 0.08 (stat)  0.14+ 0.08 (sys)a~=~1.30~\pm~0.08~(stat)~^{+~0.08}_{-~0.14}~(sys) in all bins of β\beta and Q2Q^2. In the measured Q2Q^2 range, the diffractive structure function approximately scales with Q2Q^2 at fixed β\beta. In an Ingelman-Schlein type model, where commonly used pomeron flux factor normalisations are assumed, it is found that the quarks within the pomeron do not saturate the momentum sum rule.Comment: 36 pages, latex, 11 figures appended as uuencoded fil

    Transverse momentum and centrality dependence of dihadron correlations in Au+Au collisions at sqrt(s_NN)=200 GeV: Jet-quenching and the response of partonic matter

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    Azimuthal angle \Delta\phi correlations are presented for charged hadrons from dijets for 0.4 < p_T < 10 GeV/c in Au+Au collisions at sqrt(s_NN) = 200 GeV. With increasing p_T, the away-side distribution evolves from a broad to a concave shape, then to a convex shape. Comparisons to p+p data suggest that the away-side can be divided into a partially suppressed "head" region centered at Delta\phi ~ \pi, and an enhanced "shoulder" region centered at Delta\phi ~ \pi +/- 1.1. The p_T spectrum for the "head" region softens toward central collisions, consistent with the onset of jet quenching. The spectral slope for the "shoulder" region is independent of centrality and trigger p_T, which offers constraints on energy transport mechanisms and suggests that the "shoulder" region contains the medium response to energetic jets.Comment: 420 authors from 58 institutions, 6 pages, 4 figures. Submitted to Physical Review Letters. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm
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