125551627
Study of gamma/jet separation with the ATLAS detector
125535688
Cosmic Ray, Beam-Halo and Beam-Gas Rate Studies for ATLAS Commissioning
126272154
Tagging of low-pt electrons from b decays with the ATLAS electromagnetic calorimeter
118222129
Final Report of the Simulation Optimization Task Force
This is the final report of the ATLAS Simulation Optimization Task Force, establishedin June of 2007. This note justifies the selected Geant4 version, physics list, and range cuts to be used by the default ATLAS simulation for initial data taking and beyond. The current status of several projects, including detector description, simulation validation, studies of additional Geant4 parameters, and cavern background, are reported.
14248170
Impact of energy and luminosity upgrades at LHC on the physics programme of ATLAS
The impact of possible LHC upgrades on the physics capabilities of the ATLAS detector is discussed. As a benchmark, an increase in the luminosity by a factor of 10 is considered. For comparison, the doubling of the LHC energy is also explored. Both upgrades significantly enhance the physics capabilities of ATLAS. Measured in terms of the mass reach for new particles, the energy upgrade is more powerful. However, in cases where the effect of an upgrade is to increase the precision of measurements as a result of larger data samples, the luminosity upgrade can be at least as powerful. The pile-up of minimum bias events at higher luminosity could limit the physics performance of ATLAS in areas where tagging of forward jets is needed.
16422857
Preparing for LHC data-taking with the ATLAS experiment
The status of the ATLAS experiment a few months before the start-up of LHC operation is described. Emphasis is given to the preparation for the imminent data-taking phase through commissioning studies with cosmics data. A few examples of the physics potential and goals with early LHC data are also presented.
119196535
Evaluating the maximum likelihood method for detecting short-term variability of AGILE γ-ray sources
Context. The AGILE space mission (whose instrument is sensitive to the energy ranges 18–60 keV, and 30 MeV–50 GeV) has been operating since 2007. Assessing the statistical significance of the time variability of γ-ray sources above 100 MeV is a primary task of the AGILE data analysis. In particular, it is important to verify the instrument sensitivity in terms of Poisson modeling of the data background, and to determine the post-trial confidence of detections. Aims. The goals of this work are: (i) to evaluate the distributions of the likelihood ratio test for both “empty” fields and regions of the Galactic plane, and (ii) to calculate the probability of false detections over multiple time intervals. Methods. We describe in detail the techniques used to search for short-term variability in the AGILE γ-ray source database. We describe the binned maximum likelihood method used for the analysis of AGILE data, and the numerical simulations that support the characterization of the statistical analysis. We apply our method to both Galactic and extragalactic transients, and provide a few examples. Results. After checking the reliability of the statistical description tested with the real AGILE data, we obtain the distribution of p-values for blind and specific source searches. We apply our results to the determination of the post-trial statistical significance of detections of transient γ-ray sources in terms of pre-trial values. Conclusions. The results of our analysis allow a precise determination of the post-trial significance of γ-ray sources detected by AGILE.
119226776
The AGILE Science Alert System
The AGILE Science Alert System has been developed to provide prompt processing of science data for detection and alerts on gamma-ray galactic and extra galactic transients, gamma-ray bursts, X-ray bursts and other transients in the hard X-rays. The system is distributed among the AGILE Data Center (ADC) of the Italian Space Agency (ASI), Frascati (Italy), and the AGILE Team Quick Look sites, located at INAF/IASF Bologna and INAF/IASF Roma. We present the Alert System architecture and performances in the first 2 years of operation of the AGILE payload.
121426765
The mini-calorimeter detector for the AGILE mission
AGILE is an ASI space mission for high energy astrophysics in the gamma ray energy range 30MeV-50GeV, and in the X-ray band (10keV-40keV). AGILE is composed of three detecting systems: a Tungsten-Silicon Tracker, a Csl Mini-Calorimeter and a Silicon based X-ray detector (Super-Agile), plus an anticoincidence system for background rejection. The satellite will have good imaging performances (with angular resolution of a few arc-minutes in the gamma ray band), good timing resolution and a large field of view (about 1/5 of the sky). AGILE high energy detector is composed of a Silicon Tracker, a Mini-Calorimeter, the Anticoincidence and the Data Handling system The Mini-Calorimeter can also work as a stand-alone gamma ray detector in the energy range 250keV-250MeV, with no imaging capabilities, for the detection of transients and gamma ray burst events and for the evaluation of gamma ray background fluctuations. The Mini-Calorimeter is made of 30 independent elements of 37.5 × 2.3 × 1.5  cm stacked in two layers. Each detector scintillator signal is read out via two photodiodes glued on the small surfaces of the bar. The characteristics of the engineering model detectors has been deeply investigated and will be reported.
13932374
Design and Construction of the Mini-Calorimeter of the AGILE Satellite
Abstract AGILE is a small space mission of the Italian Space Agency (ASI) devoted to gamma-ray and hard-X astrophysics, successfully launched on April 23, 2007. The AGILE Payload is composed of three instruments: a gamma-ray imager based on a tungsten-silicon tracker (ST), for observations in the gamma ray energy range 30 MeV–50 GeV, a Silicon based X-ray detector, SuperAGILE (SA), for imaging in the range 18–60 keV and a CsI(Tl) Mini-Calorimeter (MCAL) that detects gamma rays or charged particles energy loss in the range 300 keV–100 MeV. MCAL is composed of 30 CsI(Tl) scintillator bars with photodiode readout at both ends, arranged in two orthogonal layers. MCAL can work both as a slave of the ST and as an independent gamma-ray detector for transients and gamma-ray bursts detection. In this paper a detailed description of MCAL is presented together with its performance.
107972078
The Test Equipment of the AGILE Minicalorimeter Prototype
AGILE is an ASI (Italian Space Agency) Small Space Mission for high energy astrophysics in the range 30 MeV – 50 GeV. The AGILE satellite is currently in the C phase and is planned to be launched in 2005. The Payload shall consist of a Tungsten‐Silicon Tracker, a CsI Minicalorimeter, an anticoincidence system and a X‐Ray detector sensitive in the 10–40 KeV range. The purpose of the Minicalorimeter (MCAL) is twofold. It shall work in conjunction with the Tracker in order to evaluate the energy of the interacting photons, and it shall operate autonomously in the energy range 250KeV–250 MeV for detection of transients and gamma ray burst events and for the measurement of gamma ray background fluctuations. We present the architecture of the Test Equipment we have designed and developed in order to test and verify the MCAL Simplified Electrical Model prototype which has been manufactured in order to validate the design of the MCAL Proto Flight Model.