The DIRC (Detection of Internally Reflected Cerenkov (light)) is a new type of Cerenkov ring imaging detector based on total internal reflection that is used in the BABAR detector at the PEP-II ring ...of the Stanford Linear Accelerator Center, Stanford, CA. The Cerenkov radiators are long rectangular bars made of synthetic fused silica. The photon detector is a water tank equipped with an array of 10,752 conventional photomultipliers. The first-year operational experience in the BABAR detector is presented on the basis of cosmic data and collision data in the energy region of the Upsilon (4S) resonance. (Author)
A mini-TPC for SLAC B-factory commissioning Cizeron, R.; Durand, A.; Lepeltier, V. ...
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment,
1999, Letnik:
419
Conference Proceeding
An overview of a large-scale data migration Lubeck, M.; Geppert, D.; Nienartowicz, K.
20th IEEE/11th NASA Goddard Conference on Mass Storage Systems and Technologies, 2003. (MSST 2003). Proceedings,
2003
Conference Proceeding
We present an overview of the migration of the data collected by the COMPASS experiment at CERN. In less than three months, almost 300 TB will be migrated at a sustained data rate approaching 100 ...MB/s, using a distributed system with multiple nodes and data servers. This project, which is being carried out by the Database Group of CERN's IT Division and is expected to be completed by early 2003, involves both a physical media migration, from StorageTek 9940A to StorageTek 9940B tapes, and a data format conversion, from an object database management system to a hybrid persistency mechanism based on flat files referenced in a relational database management system.
The data collected at centre-of-mass energies of 188.6 GeV by ALEPH at LEP, corresponding to an integrated luminosity of 176.2 pb-1, are analysed in a search for pair-produced charged Higgs bosons ...H+/-. Three analyses are employed to select the taunutaunu, taunucs and cscs final states. No evidence for a signal is found. Upper limits are set on the production cross section as a function of the branching fraction BR(H+ to tau nu) and of the mass M(H+), assuming that the sum of the branching ratios is equal to one. In the framework of a two-Higgs-doublet model, charged Higgs bosons with masses below 65.4 GeV/c2 are excluded at 95% confidence level independently of the decay mode.
This review presents the data on clinical presentation at diagnosis in 1564 patients included in the European Registry on Cushing's syndrome (ERCUSYN), of whom 1045 (67%) had pituitary‐dependent ...Cushing's syndrome (CS) (PIT‐CS), 385 (25%) had adrenal dependent CS (ADR‐CS) and 89 (5%) had ectopic adrenocorticotropic hormone syndrome (ECT‐CS). The most frequent symptoms in the overall series were weight gain (83%), hypertension (79%), skin alterations (76%) and myopathy (70%). Diabetes mellitus was present in 32% and depression in 35% of patients. Skin alterations, menstrual irregularities and reduced libido were more prevalent in PIT‐CS patients compared to ADR‐CS patients, whereas patients with ECT‐CS more frequently had diabetes mellitus, myopathy, hirsutism and vertebral fractures compared to the other etiologies, consistent with a more severe clinical scenario. Reduced libido and bone fractures were more prevalent in men compared to women. Quality of life was poor at diagnosis, irrespective of the etiology of CS, and also associated with the presence of depression at baseline. A delay of 2 years between the onset of symptoms and diagnosis was also observed, with a high number of specialists consulted, who often missed the correct diagnosis. To develop strategies aimed at shortening the time elapsed to diagnosis, it is important to rapidly start treatment and reduce the burden of the disease on patient psychophysical health and longevity.
HEP event selection is traditionally considered a binary classification problem, involving the dichotomous categories of signal and background. In distribution fits for particle masses or couplings, ...however, signal events are not all equivalent, as the signal differential cross section has different sensitivities to the measured parameter in different regions of phase space. In this paper, I describe a mathematical framework for the evaluation and optimization of HEP parameter fits, where this sensitivity is defined on an event-by-event basis, and for MC events it is modeled in terms of their MC weight derivatives with respect to the measured parameter. Minimising the statistical error on a measurement implies the need to resolve (i.e. separate) events with different sensitivities, which ultimately represents a non-dichotomous classification problem. Since MC weight derivatives are not available for real data, the practical strategy I suggest consists in training a regressor of weight derivatives against MC events, and then using it as an optimal partitioning variable for 1-dimensional fits of data events. This CHEP2019 paper is an extension of the study presented at CHEP2018: in particular, event-by-event sensitivities allow the exact computation of the “FIP” ratio between the Fisher information obtained from an analysis and the maximum information that could possibly be obtained with an ideal detector. Using this expression, I discuss the relationship between FIP and two metrics commonly used in Meteorology (Brier score and MSE), and the importance of “sharpness” both in HEP and in that domain. I finally point out that HEP distribution fits should be optimized and evaluated using probabilistic metrics (like FIP or MSE), whereas ranking metrics (like AUC) or threshold metrics (like accuracy) are of limited relevance for these specific problems.
Background measurements during PEP-II commissioning Mattison, T.; Aston, D.; Byers, B. ...
Proceedings of the 1999 Particle Accelerator Conference (Cat. No.99CH36366),
1999, Letnik:
5
Conference Proceeding
Odprti dostop
A variety of background detectors were installed at the interaction point of PEP-II for measurements of machine backgrounds during commissioning. Results from these detectors, machine experiments, ...and simulations have been used to reduce the backgrounds at PEP-II before the installation of the BaBar physics detector.
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