Search results for "CA [SR]"
showing 10 items of 2784 documents
Measurement of inclusive jet and dijet cross sections in proton-proton collisions at 7 TeV centre-of-mass energy with the ATLAS detector
2011
Jet cross sections have been measured for the first time in proton-proton collisions at a centre-of-mass energy of 7 TeV using the ATLAS detector. The measurement uses an integrated luminosity of 17 nb−1 recorded at the Large Hadron Collider. The anti-k t algorithm is used to identify jets, with two jet resolution parameters, R=0.4 and 0.6. The dominant uncertainty comes from the jet energy scale, which is determined to within 7% for central jets above 60 GeV transverse momentum. Inclusive single-jet differential cross sections are presented as functions of jet transverse momentum and rapidity. Dijet cross sections are presented as functions of dijet mass and the angular variable χ. The res…
Measurements of underlying-event properties using neutral and charged particles in pp collisions at root s=900 GeV and root s=7 TeV with the ATLAS de…
2011
We present first measurements of charged and neutral particle-flow correlations in pp collisions using the ATLAS calorimeters. Data were collected in 2009 and 2010 at centre-of-mass energies of 900 GeV and 7 TeV. Events were selected using a minimum-bias trigger which required a charged particle in scintillation counters on either side of the interaction point. Particle flows, sensitive to the underlying event, are measured using clusters of energy in the ATLAS calorimeters, taking advantage of their fine granularity. No Monte Carlo generator used in this analysis can accurately describe the measurements. The results are independent of those based on charged particles measured by the ATLAS …
Luminosity determination in pp collisions at s=7 TeV using the ATLAS detector at the LHC
2011
Measurements of luminosity obtained using the ATLAS detector during early running of the Large Hadron Collider (LHC) at s√=7 TeV are presented. The luminosity is independently determined using several detectors and multiple algorithms, each having different acceptances, systematic uncertainties and sensitivity to background. The ratios of the luminosities obtained from these methods are monitored as a function of time and of μ, the average number of inelastic interactions per bunch crossing. Residual time- and μ-dependence between the methods is less than 2% for 0<μ<2.5. Absolute luminosity calibrations, performed using beam separation scans, have a common systematic uncertainty of ±11%, do…
Limits on the production of the standard model Higgs boson in pp collisions at root s=7 TeV with the ATLAS detector
2011
A search for the Standard Model Higgs boson at the Large Hadron Collider (LHC) running at a centre-of-mass energy of 7 TeV is reported, based on a total integrated luminosity of up to 40 pb−1 collected by the ATLAS detector in 2010. Several Higgs boson decay channels: H→γγ, H→ZZ(∗)→ℓℓℓℓ, H→ZZ→ℓℓνν, H→ZZ→ℓℓqq, H→WW(∗)→ℓνℓν and H→WW→ℓνqq (ℓ is e, μ) are combined in a mass range from 110 GeV to 600 GeV. The highest sensitivity is achieved in the mass range between 160 GeV and 170 GeV, where the expected 95% CL exclusion sensitivity is at Higgs boson production cross sections 2.3 times the Standard Model prediction. Upper limits on the cross section for its production are determined. Models wit…
Política Social Comparada entre países de la Alianza del Pacífico y de la Unión Europea: México, Finlandia y España
2014
En la actualidad no existen estudios comparativos que midan de forma global la política social como input de los gobiernos. Una alternativa es la inclusión de diversos indicadores relevantes para la política social en un solo índice, que permita realizar un análisis estadístico y comparativo de diferentes países. El objetivo de este estudio es conocer la factibilidad de medir la política social basándonos en sus input y aplicando el Social Policy Index (SPI) en tres países de diferente régimen de bienestar social, estableciendo una comparación retrospectiva de la situación de las políticas sociales entre cada uno, considerando los años 2001 a 2010. Los resultados arrojan una coherencia entr…
SINDROME DA ATTIVAZIONE MACROFAGICA SECONDARIA AD IMMUNODEFICIT
2018
Introduzione: la sindrome da attivazione macrofagica (SAM) è una condizione clinica rara, di cui esistono forme primitive (es. deficit di perforine) e secondarie ad infezioni, farmaci, immunodeficit; nel 10% dei casi rappresenta una complicanza dell'artrite idiopatica giovanile sistemica (AIG). Criteri diagnostici: febbre, epatosplenomegalia, citopenia bilineare, aumento di ferritina, transaminasi, ipertrigliceridemia ed ipofibrinogenemia con segni di emofagocitosi all'aspirato midollare. Terapia: metilprednisolone a 30 mg/Kg/die ev e terapia della patologia di base; nei no-responders trova impiego l'uso dei farmaci immunosoppressori come ciclosporina, Anakinra per forme secondarie ad AIG, …
Time-Varying mHAP-III Is the Most Accurate Predictor of Survival in Patients with Hepatocellular Carcinoma Undergoing Transarterial Chemoembolization
2021
<b><i>Introduction:</i></b> The prognosis of patients undergoing transarterial chemoembolization (TACE) is extremely variable, and a confounding factor is that TACE is often repeated several times. We retrospectively evaluated the accuracy of different prognostic scores and staging systems in estimating overall survival (OS) in patients with hepatocellular carcinoma (HCC). <b><i>Methods:</i></b> An analysis considering prognostic models as time-varying variables was performed, calculating OS from the time of TACE to the time of the subsequent treatment. Total follow-up time for each patient was therefore split into several observation times ac…
Updated measurement of the τ lepton lifetime
1997
A new measurement of the mean lifetime of the tau lepton is presented. Three different analysis methods are applied to a sample of 90000 tau pairs, collected in 1993 and 1994 with the ALEPH detector at LEP. The average of this measurement and those previously published by ALEPH is tau_tau = 290.1 +- 1.5 +- 1.1 fs.
Effects of high pressure thermal treatments in oxygen and helium atmospheres on amorphous silicon dioxide and its radiation hardness
2009
The effects of thermal treatments at similar to 400 degrees C in oxygen or helium atmospheres at similar to 180 baron the radiation hardness of amorphous SiO(2) are studied. The generation efficiency of several point defects under gamma irradiation is compared to that of the untreated material. All the effects on point defects generation here observed can be explained in terms of changes in the precursor sites. In particular it has been observed that the thermal treatments can change the precursors sites of point defects both through temperature and pressure related processes, not depending on the atmosphere, and through oxygen related processes creating oxygen excess sites. The presence of…
In-situ observation of beta-ray induced UV optical absorption in a-SiO2: radiation darkening and room temperature recovery
2006
International audience; We studied the optical absorption in the 3.0-6.2 eV range induced in bulk amorphous SiO2 by beta-ray irradiation up to similar to 1 MGy at room temperature. The induced absorption was measured in situ both during irradiation and in the post irradiation time. Our data evidence E', center as the main defect induced by irradiation and the partial decay of their absorption band at about 5.8 eV after irradiation. A quantitative analysis of the time evolution of the induced absorption shows that the transmission recovery observed after irradiation is compatible with the reaction of radiation-induced defects with H-related (H-2, H2O) species diffusing in the amorphous matrix