58 research outputs found
The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe
The preponderance of matter over antimatter in the early Universe, the
dynamics of the supernova bursts that produced the heavy elements necessary for
life and whether protons eventually decay --- these mysteries at the forefront
of particle physics and astrophysics are key to understanding the early
evolution of our Universe, its current state and its eventual fate. The
Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed
plan for a world-class experiment dedicated to addressing these questions. LBNE
is conceived around three central components: (1) a new, high-intensity
neutrino source generated from a megawatt-class proton accelerator at Fermi
National Accelerator Laboratory, (2) a near neutrino detector just downstream
of the source, and (3) a massive liquid argon time-projection chamber deployed
as a far detector deep underground at the Sanford Underground Research
Facility. This facility, located at the site of the former Homestake Mine in
Lead, South Dakota, is approximately 1,300 km from the neutrino source at
Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino
charge-parity symmetry violation and mass ordering effects. This ambitious yet
cost-effective design incorporates scalability and flexibility and can
accommodate a variety of upgrades and contributions. With its exceptional
combination of experimental configuration, technical capabilities, and
potential for transformative discoveries, LBNE promises to be a vital facility
for the field of particle physics worldwide, providing physicists from around
the globe with opportunities to collaborate in a twenty to thirty year program
of exciting science. In this document we provide a comprehensive overview of
LBNE's scientific objectives, its place in the landscape of neutrino physics
worldwide, the technologies it will incorporate and the capabilities it will
possess.Comment: Major update of previous version. This is the reference document for
LBNE science program and current status. Chapters 1, 3, and 9 provide a
comprehensive overview of LBNE's scientific objectives, its place in the
landscape of neutrino physics worldwide, the technologies it will incorporate
and the capabilities it will possess. 288 pages, 116 figure
Study of correlations between photoproduced pairs of charmed particles at Experiment E831/FOCUS
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Study of correlations between photoproduced pairs of charmed particles at Experiment E831/FOCUS
The authors present the study of the charm-pair correlations produced in photon-nucleon interactions at <E{sub {gamma}}> = 175 GeV/c, by the Fermilab fixed target experiment E831/FOCUS. The E831/FOCUS experiment produced and reconstructed over one million charm particles. This high statistics allows the reconstruction of more than 7000 charm-pair mesons D{bar D}, 10 times the statistic of former experiments, and also allows to get, for the first time, about 600 totally reconstructed charm-pairs in the DD{sub s} and D{Lambda}{sub c} channels. They were able to study, with some detail, the kinematical correlations between the charm and anticharm particle forming a pair, in the square transverse momentum (p{sub T}{sup 2}), azimuthal angle difference ({Delta}{phi}), rapidity difference ({Delta}y) and the charm-pair mass variables. They observe some correlation for the longitudinal momenta, and a significant correlation for the transverse momenta of the charm and anticharm particles. They compare the experimental distributions with theoretical predictions based on the photon-gluon fusion model (PGF), for the production of c{bar c} quarks, and the standard Lund hadronization model. These models are implemented by the PYTHIA Monte Carlo event generator. The PYTHIA program allows the inclusion, in the simulation, of non-perturbative effects that have been shown to be important for charm production. In order to compare data and simulation, they have generated two Monte Carlo samples, the first one set to favor the production of D{bar D} pairs (MCDD2), and the second one set to favor the production of DD{sub s} and D{Lambda}{sub c} pairs, where each one uses different functions and parameters values for the theoretical models in the simulation. They observe, for the correlation distributions, that the set of parameters used by the MCDD2 model together with the intrinsic transverse momentum (k{sub {perpendicular}}) of the partons inside the nucleons, has a better agreement with data distributions than the one used by the MCDSLC model. Finally, the relative pair/anti-pair yield production ratio is calculated for five sets of charm-pairs, D{sup +}D{sup 0}, D{sup +}D{sub s}{sup -}, D{sup 0}D{sub s}{sup -}, D{sup +}{Lambda}{sub c}{sup -} e D{sup 0}{Lambda}{sub c}{sup -}, both for data as well as for the two Monte Carlo samples. They observe that the MCDSLC model predicts charm-pair yield production ratios closer to the yield ratios data than the MCDD2 model
Externado De Pediatría-ME82-201402
El inicio del ciclo académico 12 marca un cambio importante en el proceso de formación del estudiante de la carrera al tratarse de un ciclo eminentemente práctico. Durante el externado el alumno rotará por las principales áreas clínico quirúrgicas que le permitirán ir consolidando las competencias del perfil del egresado propuestas por la Escuela de Medicina. Cada alumno rotará 3 semanas por un servicio de Pediatría y 1 semana en Neonatología de los diferentes hospitales concertados
Externado De Pediatría-ME82-201302
El inicio del ciclo académico 12 marca un cambio importante en el proceso de formación del estudiante de la carrera al tratarse de un ciclo eminentemente práctico. Durante el externado el alumno rotará por las principales áreas clínico quirúrgicas que le permitirán ir consolidando las competencias del perfil del egresado propuestas por la Escuela de Medicina. Cada alumno rotará 3 semanas por un servicio de Pediatría y 1 semana en Neonatología de los diferentes hospitales concertados
Externado de Pediatría - ME82 201302
El inicio del ciclo académico 12 marca un cambio importante en el proceso de formación del estudiante de la
carrera al tratarse de un ciclo eminentemente práctico. Durante el externado, el alumno rotará por las principales
áreas clínico quirúrgicas que le permitirán ir consolidando las competencias del perfil del egresado propuestas
por la Escuela de Medicina. Cada alumno rotará 3 semanas por un servicio de Pediatría y 1 semana en
Neonatología de los diferentes hospitales concertados
Externado de Pediatría - ME82 201402
El inicio del ciclo académico 12 marca un cambio importante en el proceso de formación del estudiante de la
carrera al tratarse de un ciclo eminentemente práctico. Durante el externado, el alumno rotará por las principales
áreas clínico quirúrgicas que le permitirán ir consolidando las competencias del perfil del egresado propuestas
por la Escuela de Medicina. Cada alumno rotará 3 semanas por un servicio de Pediatría y 1 semana en
Neonatología de los diferentes hospitales concertados
The DUNE Far Detector Vertical Drift Technology, Technical Design Report
International audienceDUNE is an international experiment dedicated to addressing some of the questions at the forefront of particle physics and astrophysics, including the mystifying preponderance of matter over antimatter in the early universe. The dual-site experiment will employ an intense neutrino beam focused on a near and a far detector as it aims to determine the neutrino mass hierarchy and to make high-precision measurements of the PMNS matrix parameters, including the CP-violating phase. It will also stand ready to observe supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector implements liquid argon time-projection chamber (LArTPC) technology, and combines the many tens-of-kiloton fiducial mass necessary for rare event searches with the sub-centimeter spatial resolution required to image those events with high precision. The addition of a photon detection system enhances physics capabilities for all DUNE physics drivers and opens prospects for further physics explorations. Given its size, the far detector will be implemented as a set of modules, with LArTPC designs that differ from one another as newer technologies arise. In the vertical drift LArTPC design, a horizontal cathode bisects the detector, creating two stacked drift volumes in which ionization charges drift towards anodes at either the top or bottom. The anodes are composed of perforated PCB layers with conductive strips, enabling reconstruction in 3D. Light-trap-style photon detection modules are placed both on the cryostat's side walls and on the central cathode where they are optically powered. This Technical Design Report describes in detail the technical implementations of each subsystem of this LArTPC that, together with the other far detector modules and the near detector, will enable DUNE to achieve its physics goals
The DUNE Far Detector Vertical Drift Technology, Technical Design Report
DUNE is an international experiment dedicated to addressing some of the questions at the forefront of particle physics and astrophysics, including the mystifying preponderance of matter over antimatter in the early universe. The dual-site experiment will employ an intense neutrino beam focused on a near and a far detector as it aims to determine the neutrino mass hierarchy and to make high-precision measurements of the PMNS matrix parameters, including the CP-violating phase. It will also stand ready to observe supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector implements liquid argon time-projection chamber (LArTPC) technology, and combines the many tens-of-kiloton fiducial mass necessary for rare event searches with the sub-centimeter spatial resolution required to image those events with high precision. The addition of a photon detection system enhances physics capabilities for all DUNE physics drivers and opens prospects for further physics explorations. Given its size, the far detector will be implemented as a set of modules, with LArTPC designs that differ from one another as newer technologies arise. In the vertical drift LArTPC design, a horizontal cathode bisects the detector, creating two stacked drift volumes in which ionization charges drift towards anodes at either the top or bottom. The anodes are composed of perforated PCB layers with conductive strips, enabling reconstruction in 3D. Light-trap-style photon detection modules are placed both on the cryostat's side walls and on the central cathode where they are optically powered. This Technical Design Report describes in detail the technical implementations of each subsystem of this LArTPC that, together with the other far detector modules and the near detector, will enable DUNE to achieve its physics goals
Doping liquid argon with xenon in ProtoDUNE Single-Phase: effects on scintillation light
Doping 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 of liquid argon TPCs (LArTPCs) with a smallconcentration of xenon is a technique for light-shifting andfacilitates the detection of the liquid argon scintillationlight. In this paper, we present the results of the first dopingtest ever performed in a kiloton-scale LArTPC. From February to May2020, we carried out this special run in the single-phase DUNE FarDetector prototype (ProtoDUNE-SP) at CERN, featuring 720 t of totalliquid argon mass with 410 t of fiducial mass. A 5.4 ppm nitrogencontamination was present during the xenon doping campaign. The goalof the run was to measure the light and charge response of thedetector to the addition of xenon, up to a concentration of18.8 ppm. The main purpose was to test the possibility forreduction of non-uniformities in light collection, caused bydeployment of photon detectors only within the anode planes. Lightcollection was analysed as a function of the xenon concentration, byusing the pre-existing photon detection system (PDS) of ProtoDUNE-SPand an additional smaller set-up installed specifically for thisrun. In this paper we first summarize our current understanding ofthe argon-xenon energy transfer process and the impact of thepresence of nitrogen in argon with and without xenon dopant. We thendescribe the key elements of ProtoDUNE-SP and the injection methoddeployed. Two dedicated photon detectors were able to collect thelight produced by xenon and the total light. The ratio of thesecomponents was measured to be about 0.65 as 18.8 ppm of xenon wereinjected. We performed studies of the collection efficiency as afunction of the distance between tracks and light detectors,demonstrating enhanced uniformity of response for the anode-mountedPDS. We also show that xenon doping can substantially recover lightlosses due to contamination of the liquid argon by nitrogen.Doping 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 720 t of total liquid argon mass with 410 t of fiducial mass. A 5.4 ppm nitrogen contamination was present during the xenon doping campaign. 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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