6,913 research outputs found
First observation and measurement of the resonant structure of the lambda_b->lambda_c pi-pi+pi- decay mode
We present the first observation of the lambda_b->lambda_c pi-pi+pi- decay
using data from an integrated luminosity of approximately 2.4 fb-1 of ppbar
collisions at ECM=1.96 TeV, collected with the CDF II detector at the Fermilab
Tevatron. We also present the first observation of the resonant decays
lambda_b->sigma_c(2455)0 pi+pi- ->lambda_c pi-pi+pi-, lambda_b->sigma_c(2455)++
pi-pi- ->lambda_c pi-pi+pi-, lambda_b->lambda_c(2595)+ pi- ->lambda_c pi-pi+pi-
and lambda_b->lambda_c(2625)+ pi- ->lambda_c pi-pi+pi-, and measure their
relative branching ratios.Comment: 3 pages, 3 figures, to appear in the proceedings of LEPTON PHOTON
2009, Hamburg, German
Beam test calibration of the balloon-borne imaging calorimeter for the CREAM experiment
CREAM (Cosmic Ray Energetics And Mass) is a multi-flight balloon mission
designed to collect direct data on the elemental composition and individual
energy spectra of cosmic rays. Two instrument suites have been built to be
flown alternately on a yearly base. The tungsten/Sci-Fi imaging calorimeter for
the second flight, scheduled for December 2005, was calibrated with electron
and proton beams at CERN. A calibration procedure based on the study of the
longitudinal shower profile is described and preliminary results of the beam
test are presented.Comment: 4 pages, 4 figures. To be published in the Proceedings of 29th
International Cosmic Ray Conference (ICRC 2005), Pune, India, August 3-10,
200
INFN Camera demonstrator for the Cherenkov Telescope Array
The Cherenkov Telescope Array is a world-wide project for a new generation of
ground-based Cherenkov telescopes of the Imaging class with the aim of
exploring the highest energy region of the electromagnetic spectrum. With two
planned arrays, one for each hemisphere, it will guarantee a good sky coverage
in the energy range from a few tens of GeV to hundreds of TeV, with improved
angular resolution and a sensitivity in the TeV energy region better by one
order of magnitude than the currently operating arrays. In order to cover this
wide energy range, three different telescope types are envisaged, with
different mirror sizes and focal plane features. In particular, for the highest
energies a possible design is a dual-mirror Schwarzschild-Couder optical
scheme, with a compact focal plane. A silicon photomultiplier (SiPM) based
camera is being proposed as a solution to match the dimensions of the pixel
(angular size of ~ 0.17 degrees). INFN is developing a camera demonstrator made
by 9 Photo Sensor Modules (PSMs, 64 pixels each, with total coverage 1/4 of the
focal plane) equipped with FBK (Fondazione Bruno Kessler, Italy) Near
UltraViolet High Fill factor SiPMs and Front-End Electronics (FEE) based on a
Target 7 ASIC, a 16 channels fast sampler (up to 2GS/s) with deep buffer,
self-trigger and on-demand digitization capabilities specifically developed for
this purpose. The pixel dimensions of mm lead to a very compact
design with challenging problems of thermal dissipation. A modular structure,
made by copper frames hosting one PSM and the corresponding FEE, has been
conceived, with a water cooling system to keep the required working
temperature. The actual design, the adopted technical solutions and the
achieved results for this demonstrator are presented and discussed.Comment: In Proceedings of the 34th International Cosmic Ray Conference
(ICRC2015), The Hague, The Netherlands. All CTA contributions at
arXiv:1508.0589
FULL TEMPORAL RECONSTRUCTION USING AN ADVANCED LONGITUDINAL DIAGNOSTIC AT THE SPARC FEL
FULL TEMPORAL RECONSTRUCTION USING AN ADVANCED
LONGITUDINAL DIAGNOSTIC AT THE SPARC FE
Galileo, the European GNSS program, and LAGEOS
With the ASI-INFN project âETRUSCO-2 (Extra Terrestrial Ranging to Unified Satellite COnstellations-2)â we have the opportunity to continue and enhance the work already done with the former ETRUSCO INFN experiment. With ETRUSCO (2005-2010) the SCF LAB (Satellite/lunar laser ranging Characterization Facility LABoratory) team developed a new industry-standard test for laser retroreflectors characterization (the SCF-Test). This test is an integrated and concurrent thermal and optical measurement in accurately laboratory-simulated space environment. In the same period we had the opportunity to test several flight models of retroreflectors from NASA, ESA and ASI. Doing this we examined the detailed thermal behavior and the optical performance of LAGEOS (Laser GEOdynamics Satellites) cube corner retroreflectors and many others being used on the Global Navigation Satellite System (GNSS) constellations currently in orbit, mainly GPS, GLONASS and GIOVE-A/GIOVE-B (Galileo In Orbit Validation Element) satellites, which deploy old-generation aluminium back-coated reflectors; we also SCFTested for ESA prototype new-generation uncoated reflectors for the Galileo IOV (In-Orbit Validation) satellites, which is the most important result presented here. ETRUSCO-2 inherits all this work and a new lab with doubled instrumentation (cryostat, sun simulator, optical bench) inside a new, dedicated 85m2 class 10000 (or better) clean room. This new project aims at a new revision of the SCF-Test expressly conceived to dynamically simulate the actual GNSS typical orbital environment, a new, reliable Key Performance Indicator for the future GNSS retroreflectors payload. Following up on this and using LAGEOS as a reference standard target in
terms of optical performances, the SCF LAB research team led by S. DellâAgnello is designing, building and testing a new generation of GNSS retroreflectors array (GRA) for the new European GNSS constellation Galileo
Intra-articular somatostatin 14 reduces synovial thickness in rheumatoid arthritis: An ultrasonographic study
Sixteen patients with RA (3 males, 13 females), diagnosed according to RA revised criteria, were selected and entered the study. They underwent six intra-articular injections of 750 mcg of SST14 at 15-day intervals. The thickness of the synovial membrane (SM) was measured with a 5-MHz linear sound with longitudinal and transversal scanning carried out on the upper patellar cavity. The contralateral knee was also assessed together with the injected knee in order to ascertain any systemic effect of the drug. A significant reduction of SM thickness was observed already at the first control (T3) in 14 out of 16 patients. At the 5th and 6th injections (T5 and T6) the reduction was still significant but to a lower extent. In 8 out of 16 cases a reduction of SM thickness was observed in the contralateral knee. Analysis of these data clearly shows that the intra-articular injection of SST14 is able to reduce the thickness of SM in patients with RA, and indicates that SST14 may directly reduce synovitis. This particularity has been detected in our work with a non-invasive technique such as the joint ultra-sound (US). In conclusion, our work confirms the efficacy of SST14 in the control of RA synovial hypertrophy and the reliability of US technique in the measurement of SM thickness
MOONLIGHT: A NEW LUNAR LASER RANGING RETROREFLECTOR AND THE LUNAR GEODETIC PRECESSION
Since the 1970s Lunar Laser Ranging (LLR) to the Apollo Cube Corner Retroreflector (CCR) arrays (developed by the University of Maryland, UMD) supplied almost all significant tests of General Relativity (Alley et al., 1970; Chang et al., 1971; Bender et al.,1973): possible changes in the gravitational constant, gravitational self-energy, weak equivalence principle, geodetic precession, inverse-square force-law. The LNF group, in fact, has just completed a new measurement of the lunar geodetic precession with Apollo array, with accuracy of 9 Ă 10â3, comparable to the best measurement to date. LLR has also provided significant information on the composition and origin of the moon. This is the only Apollo experiment still in operation. In the 1970s Apollo LLR arrays contributed a negligible fraction of the ranging error budget. Since the ranging capabilities of ground stations improved by more than two orders of magnitude, now, because of the lunar librations, Apollo CCR arrays dominate the error budget. With the project MoonLIGHT (Moon Laser Instrumentation for General relativity High-accuracy Tests), in 2006 INFN-LNF joined UMD in the development and test of a new-generation LLR payload made by a single, large CCR (100mm diameter) unaffected by the effect of librations. With MoonLIGHT CCRs the accuracy of the measurement of the lunar geodetic precession can be improved up to a factor 100 compared to Apollo arrays. From a technological point of view, INFN-LNF built and is operating a new experimental apparatus (Satellite/lunar laser ranging Characterization Facility, SCF) and created a new industry-standard test procedure (SCF-Test) to characterize and model the detailed thermal behavior and the optical performance of CCRs in accurately laboratory-simulated space conditions, for industrial and scientific applications. Our key experimental innovation is the concurrent measurement and modeling of the optical Far Field Diffraction Pattern (FFDP) and the temperature distribution of retroreflector payloads under thermal conditions produced with a close-match solar simulator. The apparatus includes infrared cameras for non-invasive thermometry, thermal control and real-time payload movement to simulate satellite orientation on orbit with respect to solar illumination and laser interrogation beams. These capabilities provide: unique pre-launch performance validation of the space segment of LLR/SLR (Satellite Laser Ranging); retroreflector design optimization to maximize ranging efficiency and signal-to-noise conditions in daylight. Results of the SCF-Test of our CCR payload will be presented. Negotiations are underway to propose our payload and SCF-Test services for precision gravity and lunar science measurements with next robotic lunar landing missions. In particular, a scientific collaboration agreement was signed on Jan. 30, 2012, by D. Currie, S. DellâAgnello and the Japanese PI team of the LLR instrument of the proposed SELENE-2 mission by JAXA (Registered with INFN Protocol n. 0000242-03/Feb/2012). The agreement foresees that, under no exchange of funds, the Japanese single, large, hollow LLR reflector will be SCF-Tested and that MoonLIGHT will be considered as backup instrument
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