200 research outputs found
ATLAS physics results (not Higgs)
No full textThese proceedings give a review of some of the non-Higgs physics results from ATLAS. The topics covered include Standard Model, exotics and SUSY. Rather than summarizing the very large number of results available in these areas, a few analyses are picked out to emphasize some important common themes for LHC physics. The first theme is the importance of good experimental resolution to maximize the sensitivity to new physics. As all new Beyond the Standard Model (BSM) physics will suffer from Standard Model backgrounds, a very good understanding of SM processes is also essential. The other two general themes that will be discussed are the choice of optimized variables and the use of data-driven background estimates
Incorporating landscape metrics into invertebrate fisheries management: Case study of the gooseneck barnacle in Asturias (N. Spain)
No full textWe thank the Asturian cofradías for their continuous support. This work would not have been possible without the valuable information on topographical analyses provided by Eva López and Nicolás Weidberg. This study was financed by the Spanish Government through project DOSMARES (CTM2010-21810-C03-02, Ministerio de Ciencia e Innovación, Spain). Fishery data were provided by the Dirección General de Pesca Marítima del Principado de Asturias. SIGMA S.L. provided support on quality classifications. A.R. was supported by an FPU fellowship (Ref. AP2010-5376, Ministerio de Educación de España, Grant no. AP2010-5376). A.R. and S.G. thank the Iniciativa Científica Milenio P10-033F, NC 120086, and Conicyt FB 0002
Frequency scanned interferometry (FSI): The basis of a survey system for ATLAS using fast automated remote interferometry
No full textA novel optical survey system for continuous alignment of HEP experiments is described. The complete survey system is outlined and the underlying measurement technique, FSI, is described in detail. Preliminary findings made with a laboratory demonstration system for FSI are presented
Optical data links for the ATLAS SCT and Pixel Detector
No full textATLAS (The ATLAS Technical Proposal, CERN/LHCC 94-33) is one of the large electronic particle detectors at LHC (The LHC Conceptual Design, Report- The Yellow Book, CERN/AC/95-05(LHC)) which will become operational in 2005. It is planned to use radiation tolerant optical links for the data transfer from the SemiConductor Tracker (SCT) (ATLAS Inner Detector Technical Proposal, CERN/LHCC 97-16 and CERN/LHCC 97-17). and Pixel Detector (ATLAS Pixel Detector Technical Proposal, CERN/LHCC 98-13) systems to the acquisition electronics over a distance up to 140m. The overall architecture and the performance of these optical data links are described. One of the three candidate designs for an on-detector Opto-Package is presented. (C) 2001 Published by Elsevier Science B.V
Radiation hardness studies of the front end ASICs for the optical links of the ATLAS SemiConductor Tracker
No full textStudies have been performed on the effects of radiation on ASICs incorporating bipolar npn transistors in the AMS 0.8 mu m BiCMOS process. Radiation effects are reviewed and the approach used to achieve radiation tolerant ASICs is described. The radiation tests required to validate the ASICs for use in the ATLAS detector at the CERN Large Hadron Collider are discussed. The results demonstrate that they are sufficiently radiation tolerant for use in the ATLAS semiconductor tracker. (20 refs)
Radiation hardness and lifetime studies of LEDs and VCSELs for the optical readout of the ATLAS SCT
No full textWe study the radiation hardness and the lifetime of Light Emitting Diodes (LEDs) and Vertical Cavity Surface Emitting Laser diodes (VCSELs) in the context of the development of the optical readout for the ATLAS SemiConductor Tracker (SCT) at LHC. About 170 LEDs from two different manufacturers and about 130 VCSELs were irradiated with neutron and proton fluences equivalent to (and in some cases more than twice as high as) the combined neutral and charged particle fluence of about 5×1014 n (1 MeV eq. in GaAs)/cm2 expected in the ATLAS inner detector. We report on the radiation damage and the conditions required for its partial annealing under forward bias, we calculate radiation damage constants, and we present post-irradiation failure rates for LEDs and VCSELs. The lifetime after irradiation was investigated by operating the diodes at an elevated temperature of 50 °C for several months, resulting in operating times corresponding to up to 70 years of operation in the ATLAS SCT. From our results we estimate the signal-to-noise ratio and the failure rate of optical links using LEDs developed specifically for application at LHC
Author Correction: A detailed map of Higgs boson interactions by the ATLAS experiment ten years after the discovery
No full textIn the version of this article initially published, the ATLAS Collaboration
author names, affiliations and acknowledgements were omitted and
have now been included in the HTML and PDF versions of the article
Single event upset studies with the optical links of the ATLAS semiconductor tracker
No full textStudies have been performed of Single Event Upsets in the ATLAS SemiConductor Tracker optical links system. The measurements were made using low energy neutrons, and pion and proton beams in the momentum range 300-465MeV/c. The implications for the operation of the system in ATLAS during high luminosity LHC operation are discussed. © 2002 Elsevier Science B.V. All rights reserved
Final results of radiation hardness and lifetime studies of LEDs and VCSELs for optical links of the ATLAS inner detector
No full textSearch for a CP-odd Higgs boson decaying to Zh in pp collisions at root s=8 TeV with the ATLAS detector
No full textSee paper for full list of authors – 13 pages plus author list + cover pages (30 pages total), 5 figures, 2 tables, submitted to Phys. Lett. B, All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/HIGG-2013-06/International audienceA search for a heavy, CP-odd Higgs boson, , decaying into a boson and a 125 GeV Higgs boson, , with the ATLAS detector at the LHC is presented. The search uses proton--proton collision data at a centre-of-mass energy of 8 TeV corresponding to an integrated luminosity of 20.3 fb. Decays of CP-even bosons to or pairs with the boson decaying to electron or muon pairs are considered, as well as decays with the boson decaying to neutrinos. No evidence for the production of an boson in these channels is found and the 95% confidence level upper limits derived for \sigma (gg\rightarrow A) \times \mbox{BR}(A \rightarrow Zh) \times \mbox{BR}(h \rightarrow f\bar{f}) are 0.098--0.013 pb for and 0.57--0.014 pb for in a range of 220--1000 GeV. The results are combined and interpreted in the context of two-Higgs doublet models
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