3,119 research outputs found

    A study of nuclear effects in ν\nu interactions with the NOMAD detector

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    Nuclear effects in \numucc interactions with carbon nuclei have been studied by using backward going protons and π−\pi^-. Detailed analyses, of the momentum distributions and of the production rates, have been carried out in order to understand the mechanism producing these particles. The backward proton data have been compared with the predictions of the reinteraction and the short range correlation models.Comment: 8 pages, 7 figures, to be published in Proc. of NUINT01, The First International Workshop on Neutrino-Nucleus Interactions in the Few GeV Region; December 13-16 2001, KEK Tsukuba, Japa

    NA48 Results on Kaon and Hyperon Decays Relevant to |V_us|

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    New results from the NA48 experiment on kaon and hyperon decays relevant to |V_us| are reported here. For charged kaons we present measurements of BR(K+- -> pi0 e+- nu) and BR(K+- -> pi0 mu+- nu). On neutral kaon decays we report the measurements of BR(K_L -> pi+ pi-) and of K_L -> pi+- mu-+ nu form factors slopes. For hyperons we present results on the BR(Xi0 -> Sigma+ e- nu_e).Comment: 4 pages, 3 figures, to appear in the proceedings of CKM 2006, 4th International Workshop on the CKM Unitarity Triangle, December 12-16, 2006 Nagoya, Japa

    Laser-Accelerated proton beams as diagnostics for cultural heritage

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    This paper introduces the first use of laser-generated proton beams as diagnostic for materials of interest in the domain of Cultural Heritage. Using laser-accelerated protons, as generated by interaction of a high-power short-pulse laser with a solid target, we can produce proton-induced X-ray emission spectroscopies (PIXE). By correctly tuning the proton flux on the sample, we are able to perform the PIXE in a single shot without provoking more damage to the sample than conventional methodologies. We verify this by experimentally irradiating materials of interest in the Cultural Heritage with laser-accelerated protons and measuring the PIXE emission. The morphological and chemical analysis of the sample before and after irradiation are compared in order to assess the damage provoked to the artifact. Montecarlo simulations confirm that the temperature in the sample stays safely below the melting point. Compared to conventional diagnostic methodologies, laser-driven PIXE has the advantage of being potentially quicker and more efficien

    Laser-Generated Proton Beams for High-Precision Ultra-Fast Crystal Synthesis

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    We present a method for the synthesis of micro-crystals and micro-structured surfaces using laseraccelerated protons. In this method, a solid surface material having a low melting temperature is irradiated with very-short laser-generated protons, provoking in the ablation process thermodynamic conditions that are between the boiling and the critical point. The intense and very quick proton energy deposition (in the ns range) induces an explosive boiling and produces microcrystals that nucleate in a plasma plume composed by ions and atoms detached from the laser-irradiated surface. The synthesized particles in the plasma plume are then deposited onto a cold neighboring, non-irradiated, solid secondary surface. We experimentally verify the synthesizing methods by depositing low-meltingmaterial microcrystals - such as gold - onto nearby silver surfaces and modeling the proton/matter interaction via a Monte Carlo code, confrming that we are in the above described thermodynamic conditions. Morphological and crystallinity measurements indicate the formation of gold octahedral crystals with dimensions around 1.2 μm, uniformly distributed onto a silver surface with dimensions in the tens of mm2. This laser-accelerated particle based synthesis method paves the way for the development of new material synthesis using ultrashort laser-accelerated particle beams
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