5 research outputs found

    On some notions of good reduction for endomorphisms of the projective line

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    Let Φ\Phi be an endomorphism of \SR(\bar{\Q}), the projective line over the algebraic closure of \Q, of degree 2\geq2 defined over a number field KK. Let vv be a non-archimedean valuation of KK. We say that Φ\Phi has critically good reduction at vv if any pair of distinct ramification points of Φ\Phi do not collide under reduction modulo vv and the same holds for any pair of branch points. We say that Φ\Phi has simple good reduction at vv if the map Φv\Phi_v, the reduction of Φ\Phi modulo vv, has the same degree of Φ\Phi. We prove that if Φ\Phi has critically good reduction at vv and the reduction map Φv\Phi_v is separable, then Φ\Phi has simple good reduction at vv.Comment: 15 page

    Implementação da seleção recorrente no melhoramento de plantas autógamas através da macho-esterilidade Implementation of recurrent selection in plant breding of autogamous crops through male sterility

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    Os sistemas de melhoramento convencionais baseados no método genealógico, utilizados principalmente em cereais de estação fria, determinam a redução da variabilidade e da capacidade de recombinação, devido a utilização de um número de genitores limitado nos cruzamentos. O incremento da probabilidade de recombinação através da seleção recorrente pelo aumento do número de cruzamentos pode ser a saída para este problema. A utilização da macho-esterilidade representa uma alternativa viável para propiciar o cruzamento natural em espécies de autofecundação, favorecendo a utilização da seleção recorrente como uma importante ferramenta para o melhoramento de plantas autógamas.<br>The mechanism of pedigree system used in smallgrain cereals reduce genetic variability and recombination capacity due to the limited number of parent used in crosses. The increase in recombination through recurrent selection by maximizing number of crosses may be a solution for this problem. The use of male sterility may overcome the difficult of performing artificial crosses, supporting recurrent selection as a viable and important tool for autogamous crops breeding

    Doping Liquid Argon with Xenon in ProtoDUNE Single-Phase: Effects on Scintillation Light

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    International audienceDoping of liquid argon TPCs (LArTPCs) with a small concentration of xenon is a technique for light-shifting and facilitates the detection of the liquid argon scintillation light. In this paper, we present the results of the first doping test ever performed in a kiloton-scale LArTPC. From February to May 2020, we carried out this special run in the single-phase DUNE Far Detector prototype (ProtoDUNE-SP) at CERN, featuring 770 t of total liquid argon mass with 410 t of fiducial mass. The goal of the run was to measure the light and charge response of the detector to the addition of xenon, up to a concentration of 18.8 ppm. The main purpose was to test the possibility for reduction of non-uniformities in light collection, caused by deployment of photon detectors only within the anode planes. Light collection was analysed as a function of the xenon concentration, by using the pre-existing photon detection system (PDS) of ProtoDUNE-SP and an additional smaller set-up installed specifically for this run. In this paper we first summarize our current understanding of the argon-xenon energy transfer process and the impact of the presence of nitrogen in argon with and without xenon dopant. We then describe the key elements of ProtoDUNE-SP and the injection method deployed. Two dedicated photon detectors were able to collect the light produced by xenon and the total light. The ratio of these components was measured to be about 0.65 as 18.8 ppm of xenon were injected. We performed studies of the collection efficiency as a function of the distance between tracks and light detectors, demonstrating enhanced uniformity of response for the anode-mounted PDS. We also show that xenon doping can substantially recover light losses due to contamination of the liquid argon by nitrogen

    Doping Liquid Argon with Xenon in ProtoDUNE Single-Phase: Effects on Scintillation Light

    No full text
    International audienceDoping of liquid argon TPCs (LArTPCs) with a small concentration of xenon is a technique for light-shifting and facilitates the detection of the liquid argon scintillation light. In this paper, we present the results of the first doping test ever performed in a kiloton-scale LArTPC. From February to May 2020, we carried out this special run in the single-phase DUNE Far Detector prototype (ProtoDUNE-SP) at CERN, featuring 770 t of total liquid argon mass with 410 t of fiducial mass. The goal of the run was to measure the light and charge response of the detector to the addition of xenon, up to a concentration of 18.8 ppm. The main purpose was to test the possibility for reduction of non-uniformities in light collection, caused by deployment of photon detectors only within the anode planes. Light collection was analysed as a function of the xenon concentration, by using the pre-existing photon detection system (PDS) of ProtoDUNE-SP and an additional smaller set-up installed specifically for this run. In this paper we first summarize our current understanding of the argon-xenon energy transfer process and the impact of the presence of nitrogen in argon with and without xenon dopant. We then describe the key elements of ProtoDUNE-SP and the injection method deployed. Two dedicated photon detectors were able to collect the light produced by xenon and the total light. The ratio of these components was measured to be about 0.65 as 18.8 ppm of xenon were injected. We performed studies of the collection efficiency as a function of the distance between tracks and light detectors, demonstrating enhanced uniformity of response for the anode-mounted PDS. We also show that xenon doping can substantially recover light losses due to contamination of the liquid argon by nitrogen

    Doping Liquid Argon with Xenon in ProtoDUNE Single-Phase: Effects on Scintillation Light

    No full text
    International audienceDoping of liquid argon TPCs (LArTPCs) with a small concentration of xenon is a technique for light-shifting and facilitates the detection of the liquid argon scintillation light. In this paper, we present the results of the first doping test ever performed in a kiloton-scale LArTPC. From February to May 2020, we carried out this special run in the single-phase DUNE Far Detector prototype (ProtoDUNE-SP) at CERN, featuring 770 t of total liquid argon mass with 410 t of fiducial mass. The goal of the run was to measure the light and charge response of the detector to the addition of xenon, up to a concentration of 18.8 ppm. The main purpose was to test the possibility for reduction of non-uniformities in light collection, caused by deployment of photon detectors only within the anode planes. Light collection was analysed as a function of the xenon concentration, by using the pre-existing photon detection system (PDS) of ProtoDUNE-SP and an additional smaller set-up installed specifically for this run. In this paper we first summarize our current understanding of the argon-xenon energy transfer process and the impact of the presence of nitrogen in argon with and without xenon dopant. We then describe the key elements of ProtoDUNE-SP and the injection method deployed. Two dedicated photon detectors were able to collect the light produced by xenon and the total light. The ratio of these components was measured to be about 0.65 as 18.8 ppm of xenon were injected. We performed studies of the collection efficiency as a function of the distance between tracks and light detectors, demonstrating enhanced uniformity of response for the anode-mounted PDS. We also show that xenon doping can substantially recover light losses due to contamination of the liquid argon by nitrogen
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