2,206 research outputs found

    Study of the performance of the NA62 Small-Angle Calorimeter at the DAΦ\PhiNE Linac

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    The measurement of BR(K+→π+ννˉ)BR(K^+\to\pi^+\nu\bar{\nu}) with 10% precision by the NA62 experiment requires extreme background suppression. The Small Angle Calorimeter aims to provide an efficient veto for photons flying at angles down to zero with respect to the kaon flight direction. The initial prototype was upgraded and tested at the Beam Test Facility of the DAΦ\PhiNE Linac at Frascati. The energy resolution and the efficiency were measured and are presented.Comment: 5 pages, 7 figure

    Precision test of the SM with Kl2 and Kl3 decays at KLOE

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    Kaon decay studies seeking new-physics (NP) effects in leptonic (K_l2) or semileptonic (K_l3) decays are discussed. A unitarity test of the first row of the CKM mixing matrix is obtained from the KLOE precision measurements of Kl3 widths for K^+-, K_L, and (unique to KLOE) K_S, complemented with the absolute branching ratio for the K_mu2 decay. KLOE results lead to constraints for NP models and can probe possible charged Higgs exchange contribution in SM extensions with two Higgs doublets. The main focus in the present document is set on a new measurement of R_K=Gamma(K_e2)/Gamma(K_mu2) with an accuracy at the % level, aiming at finding evidence of deviations from the SM prediction induced by lepton-flavor violation NP effects.Comment: Contributed to Rencontres de Moriond EW 2009, La Thuile, Italy, 7-14 March 200

    Interleukin-13 (IL-13)in autoimmune rheumatic diseases: relationship with autoantibody profile

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    Objective: Several cytokines play a role in the production of autoantibodies such as RF and ANA by B-lymphocytes; the role of IL- 13 in this process has not been previously studied. We investigated the relationship between the serum concentration of this cytokine and circulating autoantibodies. Methods: IL-13 serum levels, as well as RF and ANA, were evaluated in 282 patients with autoimmune rheumatic diseases including RA (n=84), SLE (n = 114), SS (n = 52) and Scl (n =32). Results: Serum levels of IL-13 (pg/ml) were significantly higher in patients with RA (p < 0.00003), SLE (p < 0.03), SS (p < 0.0007), or Scl (p < 0.025) compared to controls. IL-13 serian levels correlated with those of RF in RA (p < 0.00001), SLE (p < 0.003) and Scl (p < 0.03). IL- 13 levels were higher in RA (p<0.0003), SLE (p<0.005) and Scl (p<0.05) patients with RF than in patients,without RE SS patients with anti-SSA/Ro antibodies had significantly higher IL-13 levels than SS patients without this autoantibody (p < 0.04). No statistically significant correlation was found between IL-13 levels and any other antinuclear autoantibody, total immunoglobulin levels or the main clinical features of each disease. Conclusion: The evidence of higher IL- 13 levels in our RA, SLE, SS and Scl patients confirms that this cytokine is involved in the pathogenesis of autoimmune rheumatic diseases. The relationship of this cytokine with RF in RA, SLE and Scl, as well as with antiSSA/ Ro antibody in SS, strengthens the hypothesis that it plays a role in autoantibody production. However the different autoantibody synthesis by Bcells recognises different pathways depending on the underlying autoimmune disease

    Searches for Physics Beyond the Standard Model at Colliders

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    All experimental measurements of particle physics today are beautifully described by the Standard Model. However, there are good reasons to believe that new physics may be just around the corner at the TeV energy scale. This energy range is currently probed by the Tevatron and HERA accelerators and selected results of searches for physics beyond the Standard Model are presented here. No signals for new physics have been found and limits are placed on the allowed parameter space for a variety of different particles.Comment: Proceedings for 2007 Europhysics Conference on High Energy Physics, Manchester, July 200

    A prototype large-angle photon veto detector for the P326 experiment at CERN

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    The P326 experiment at the CERN SPS has been proposed with the purpose of measuring the branching ratio for the decay K^+ \to \pi^+ \nu \bar{\nu} to within 10%. The photon veto system must provide a rejection factor of 10^8 for \pi^0 decays. We have explored two designs for the large-angle veto detectors, one based on scintillating tiles and the other using scintillating fibers. We have constructed a prototype module based on the fiber solution and evaluated its performance using low-energy electron beams from the Frascati Beam-Test Facility. For comparison, we have also tested a tile prototype constructed for the CKM experiment, as well as lead-glass modules from the OPAL electromagnetic barrel calorimeter. We present results on the linearity, energy resolution, and time resolution obtained with the fiber prototype, and compare the detection efficiency for electrons obtained with all three instruments.Comment: 8 pages, 9 figures, 2 tables. Presented at the 2007 IEEE Nuclear Science Symposium, Honolulu HI, USA, 28 October - 3 November 200

    Project HOME

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    This research project is focused on providing future astronauts ways to grow a complete diet on a planet that does not receive as much sunlight as Earth does. We evaluated a deep-water culture indoor hydroponics system to grow Moringa Oleifera, a nutrient- and antioxidant-rich plant with leaves containing all nine essential amino acids. After initial aquaponics growth and 3 prior harvests, the lighting intensity was set to 590 W/m^2 in a twelve hour on/off cycle. This simulates an ambient light collection and reflection system on Mars. 32 plants were harvested 17 times over a 9 month period at regular intervals, when plant heights reached an average of 0.9 m and we found consumable leaf yield averaged 0.18g per plant, per day. Data suggests using Moringa Oleifera as a perennial hydroponic crop is possible under reduced illumination, and is a candidate food source for Mars explorers. Preliminary research has expanded to utilizing natural light, additional plants, three more hydroponic systems, and solar power. Currently, a solar powered 8x12ft greenhouse is being used to hydroponically grow Goji Berries, Moringa Oleifera, Bamboo, Kale, Chia, and Sweet Potatoes. Combined, these foods contain a complete set of nutrients needed for a balanced human diet. The greenhouse and solar panels receive 590 W/m^2 by utilizing shade cloths. In conclusion, the project demonstrates that astronauts will have great potential in future missions to Mars to maximize the growth of superfoods using natural light, with a focus on a hydroponics system as the preferred farming method for space
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