Performance study of the CMS barrel resistive plate chambers with cosmic rays

In October and November 2008, the CMS collaboration conducted a programme of cosmic ray data taking, which has recorded about 270 million events. The Resistive Plate Chamber system, which is part of the CMS muon detection system, was successfully operated in the full barrel. More than 98% of the channels were operational during the exercise with typical detection efficiency of 90%. In this paper, the performance of the detector during these dedicated runs is reported. © 2010 IOP Publishing Ltd and SISSA.

Performance of the CMS cathode strip chambers with cosmic rays

The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47μm to 243μm. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns. © 2010 IOP Publishing Ltd and SISSA.

Aligning the CMS muon chambers with the muon alignment system during an extended cosmic ray run

The alignment system for the muon spectrometer of the CMS detector comprises three independent subsystems of optical and analog position sensors. It aligns muon chambers with respect to each other and to the central silicon tracker. System commissioning at full magnetic field began in 2008 during an extended cosmic ray run. The system succeeded in tracking muon detector movements of up to 18 mm and rotations of several milliradians under magnetic forces. Depending on coordinate and subsystem, the system achieved chamber alignment precisions of 140-350 μm and 30-200 μrad, close to the precision requirements of the experiment. Systematic errors on absolute positions are estimated to be 340-590 μm based on comparisons with independent photogrammetry measurements. © 2010 IOP Publishing Ltd and SISSA.

Precise mapping of the magnetic field in the CMS barrel yoke using cosmic rays

The CMS detector is designed around a large 4 T superconducting solenoid, enclosed in a 12 000-tonne steel return yoke. A detailed map of the magnetic field is required for the accurate simulation and reconstruction of physics events in the CMS detector, not only in the inner tracking region inside the solenoid but also in the large and complex structure of the steel yoke, which is instrumented with muon chambers. Using a large sample of cosmic muon events collected by CMS in 2008, the field in the steel of the barrel yoke has been determined with a precision of 3 to 8% depending on the location. © 2010 IOP Publishing Ltd and SISSA.

Determinantes económicos del salario mínimo en países pequeños y abiertos: una aplicación para Centroamérica

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Performance of CMS muon reconstruction in cosmic-ray events

The performance of muon reconstruction in CMS is evaluated using a large data sample of cosmic-ray muons recorded in 2008. Efficiencies of various high-level trigger, identification, and reconstruction algorithms have been measured for a broad range of muon momenta, and were found to be in good agreement with expectations from Monte Carlo simulation. The relative momentum resolution for muons crossing the barrel part of the detector is better than 1% at 10 GeV/c and is about 8% at 500 GeV/c, the latter being only a factor of two worse than expected with ideal alignment conditions. Muon charge misassignment ranges from less than 0.01% at 10GeV/c to about 1% at 500 GeV/c. © 2010 IOP Publishing Ltd and SISSA.

First measurement of the underlying event activity at the LHC with √ = 0.9 TeV

A measurement of the underlying activity in scattering processes with pT scale in the GeV region is performed in proton-proton collisions at √ = 0.9 TeV, using data collected by the CMS experiment at the LHC. Charged particle production is studied with reference to the direction of a leading object, either a charged particle or a set of charged particles forming a jet. Predictions of several QCD-inspired models as implemented in PYTHIA are compared, after full detector simulation, to the data. The models generally predict too little production of charged particles with pseudorapidity {pipe}η{pipe} < 2, pT > 0.5 GeV/c, and azimuthal direction transverse to that of the leading object. © 2010 CERN for benefit of the CMS collaboration.

Resultados y rendimiento del gasto en el sector público de salud en Chile 1990-1999

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Reforma al sector salud en Argentina

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Prompt and non-prompt J/ψ production in pp collisions at √s =7 TeV

The production of J/ψ mesons is studied in pp collisions at √s = 7 TeV with the CMS experiment at the LHC. The measurement is based on a dimuon sample corresponding to an integrated luminosity of 314 nb-1. The J/ψ differential cross section is determined, as a function of the J/ψ transverse momentum, in three rapidity ranges. A fit to the decay length distribution is used to separate the prompt from the non-prompt (b hadron to J/ψ) component. Integrated over J/ψ transverse momentum from 6.5 to 30 GeV/c and over rapidity in the range {pipe}y{pipe} < 2.4, the measured cross sections, times the dimuon decay branching fraction, are 70.9 ± 2.1(stat.) ± 3.0(syst.) ± 7.8(luminosity) nb for prompt J/ψ mesons assuming unpolarized production and 26.0 ± 1.4(stat.) ± 1.6(syst.) ± 2.9(luminosity) nb for J/ψ mesons from b-hadron decays. © CERN for the benefit of the CMS collaboration 2011.

Flexiguridad con informalidad: opciones y restricciones

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El desarrollo sostenible de los asentamientos humanos en América Latina y el Caribe

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Pobreza en América Latina: nuevos escenarios y desafíos de políticas para el hábitat urbano

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Las nuevas funciones urbanas: gestión para la ciudad sostenible

El concepto y la práctica en materia de gestión urbana-territorial se han modificado sustancialmente en los últimos años en América Latina y el Caribe, desarrollándose para abarcar asuntos y problemas vinculados al desarrollo urbano, que tradicionalmente no hacían parte del quehacer profesional en esta materia. Las razones: la consolidación de los procesos de descentralización y la modernización del estado en el marco del desafío que la globalización impone a los países de la región. La consolidación de una nueva economía urbana, que se caracteriza por una estrecha interrelación entre sistemas complejos (servicios, comunicaciones, producción, información, infraestructura) como asimismo el surgimiento de una estructura social-territorial marcada por los problemas de equidad y vulnerabilidad hacen parte de una realidad del hábitat en la región que impone nuevos desafíos y tareas. Precisamente estas nuevas formas de conceptualizar las intervenciones y la gestión urbana son presentadas por un conjunto de expertos en el presente documento. En primer lugar Ricardo Jordán y Daniela Simioni presentan el proyecto Instrumentos y estrategias de gestión urbana para el desarrollo sostenible", que considera particularmente el rol del municipio en tres ejes temáticos claves para la gestión urbana: las intervenciones para la pobreza urbana; la gestión de servicios públicos y la rehabilitación de lugares centrales. Todo ello en el marco de las características que asume hoy el proceso de urbanización en la región. A continuación Carmen Bellet Sanfeliu y Josep Maria Llop Torne nos presentan un programa de trabajo en torno al tema de las ciudades intermedias y la urbanización mundial, desarrollado por la Unión Internacional de Arquitectos (UIA). El énfasis esta puesto en el diseño de estrategias de gestión para ciudades intermedias sustentadas en una amplia participación de la comunidad. Rubén Pesci aporta otro novedoso enfoque para desarrollar una gestión que tenga por objetivo la sostenibilidad en ciudades intermedias en América Latina. La presentación involucra los aspectos conceptuales y de definición, un análisis de la situación y la descripción de algunos casos emblemáticos en la región. Vinculado con la presentación anterior, finalmente Liana Vallicelli presenta un caso 'Clásico' en América Latina: Curitiba (Brazil). Fundamental en este sentido es la evaluación que se hace de la experiencia y de las lecciones aprendidas para la gestión sostenible."

Búsqueda de cohesión social y sostenibilidad fiscal en los procesos de descentralización

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