The ATLAS data quality defect database system Golling, T.; Hayward, H. S.; Onyisi, P. U. E. ...
The European physical journal. C, Particles and fields,
04/2012, Letnik:
72, Številka:
4
Journal Article
Recenzirano
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The ATLAS experiment at the Large Hadron Collider has implemented a new system for recording information on detector status and data quality, and for transmitting this information to users performing ...physics analysis. This system revolves around the concept of “defects,” which are well-defined, fine-grained, unambiguous occurrences affecting the quality of recorded data. The motivation, implementation, and operation of this system is described.
ATLAS offline data quality monitoring Adelman, J; Baak, M; Boelaert, N ...
Journal of physics. Conference series,
04/2010, Letnik:
219, Številka:
4
Journal Article
Recenzirano
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The ATLAS experiment at the Large Hadron Collider reads out 100 Million electronic channels at a rate of 200 Hz. Before the data are shipped to storage and analysis centres across the world, they ...have to be checked to be free from irregularities which render them scientifically useless. Data quality offline monitoring provides prompt feedback from full first-pass event reconstruction at the Tier-0 computing centre and can unveil problems in the detector hardware and in the data processing chain. Detector information and reconstructed proton-proton collision event characteristics are distilled into a few key histograms and numbers which are automatically compared with a reference. The results of the comparisons are saved as status flags in a database and are published together with the histograms on a web server. They are inspected by a 24/7 shift crew who can notify on-call experts in case of problems and in extreme cases signal data taking abort.
At the ATLAS experiment, the Detector Control System (DCS) is used to oversee detector conditions and supervise the running of equipment. It is essential that information from the DCS about the ...status of individual sub-detectors be extracted and taken into account when determining the quality of data taken and its suitability for different analyses. DCS information is written to the ATLAS conditions database and then summarised to provide a status flag for each sub-detector and displayed on the web. We discuss how this DCS information should be used, and the technicalities of making this summary.
The first measurements of the coherence factor R_{K_S^0K\pi} and the average strong--phase difference \delta^{K_S^0K\pi} in D^0 \to K_S^0 K^\mp\pi^\pm decays are reported. These parameters can be ...used to improve the determination of the unitary triangle angle \gamma\ in B^- \rightarrow \(\widetilde{D}K^-\) decays, where \(\widetilde{D}\) is either a D^0 or a D^0-bar meson decaying to the same final state, and also in studies of charm mixing. The measurements of the coherence factor and strong-phase difference are made using quantum-correlated, fully-reconstructed D^0D^0-bar pairs produced in e^+e^- collisions at the \psi(3770) resonance. The measured values are R_{K_S^0K\pi} = 0.70 \pm 0.08 and \delta^{K_S^0K\pi} = (0.1 \pm 15.7)\(^\circ\) for an unrestricted kinematic region and R_{K*K} = 0.94 \pm 0.12 and \delta^{K*K} = (-16.6 \pm 18.4)\(^\circ\) for a region where the combined K_S^0 \pi^\pm invariant mass is within 100 MeV/c^2 of the K^{*}(892)^\pm mass. These results indicate a significant level of coherence in the decay. In addition, isobar models are presented for the two decays, which show the dominance of the K^*(892)^\pm resonance. The branching ratio {B}(D^0 \rightarrow K_S^0K^+\pi^-)/{B}(D^0 \rightarrow K_S^0K^-\pi^+) is determined to be 0.592 \pm 0.044 (stat.) \pm 0.018 (syst.), which is more precise than previous measurements.
I review some recent results on hadronic decays of charmed mesons. These decays illuminate a wide range of physics, including the absolute normalizations of b and c decays, the understanding of D^0 ...mixing, the coupling of heavy mesons to hadronic decay products, and light hadron spectroscopy.
The ATLAS experiment at the Large Hadron Collider has implemented a new system for recording information on detector status and data quality, and for transmitting this information to users performing ...physics analysis. This system revolves around the concept of "defects," which are well-defined, fine-grained, unambiguous occurrences affecting the quality of recorded data. The motivation, implementation, and operation of this system is described.
The CLEO-c experiment, running at charm threshold, has measured many charmed meson properties. Here I summarize results on leptonic and semileptonic decays of D mesons, as well as measurements ...hadronic decay strong phases that are relevant to the extraction of the CKM angle gamma from B decays.
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