Electrical tests of e. m. barrel presampler sectors

A description of the tests and electronics used to control the presampler sectors, before and after their assembly, is given. An example of the results obtained for the first two sectors, tested at room and liquid nitrogen temperatures, is shown

Electronic tests of the barrel presampler mother boards

The electrical characteristics of the barrel presampler mother boards are recalled. The results of the tests of the first full-size mother board are presented. They satisfy our specifications

34. HIGH-RESOLUTION ELECTRICAL IMAGING IN THE NEW HEBRIDES ISLAND ARC: STRUCTURAL ANALYSIS AND STRESS STUDIES

ABSTRACT Electrical images recorded with the Formation MicroScanner in three of seven holes drilled during Leg 134 were analyzed to study the effect of the collision of the d'Entrecasteaux Ridge with the central New Hebrides Island Arc. Structural features such as bedding, faults, fractures, folds, and shear zones, automatically detected and interactively mapped from the images, were interpreted to document the deformation processes caused by the collision. At Site 829 the images show the imbricated structure of the thrust sheets in the accretionary complex. At Sites 832 and 833 the structural features observed and the compressional-stress information inferred from breakout analyses and hydraulic fractures indicate that the intra-arc North Aoba Basin is still subject to a east-northeast-west-southwest compression. This compression, which is associated with the uplift of the eastern part of the basin, is not older than latest Pliocene

A liquid Xenon Positron Emission Tomograph for small animal imaging : first experimental results of a prototype cell

A detector using liquid Xenon (LXe) in the scintillation mode is studied for Positron Emission Tomography (PET) of small animals. Its specific design aims at taking full advantage of the Liquid Xenon scintillation properties. This paper reports on energy, time and spatial resolution capabilities of the first LXe prototype module equipped with a Position Sensitive Photo- Multiplier tube (PSPMT) operating in the VUV range (178 nm) and at 165 K. The experimental results show that such a LXe PET configuration might be a promising solution insensitive to any parallax effect.Comment: 34 pages, 18 pages, to appear in NIM

Excitation mapping of whispering gallery modes in silica microcavities

We report the direct observation of the electromagnetic-field distribution of whispering?gallery modes in silica microcavities (spheres and toroids). It is revealed by their excitation efficiency with a tapered fiber coupler swept along the meridian. The originality of this method lies in the use of the coupler itself for the near field mapping, eliminating the need of additional tools used in previous work. This method is successfully applied to microspheres and microtoroid

Mechanical design report of the barrel liquid argon presampler

The note describes the mechanical design of the Atlas barrel presampler and its evolution since the publication of thecalorimeter TDR in December 9

Measurement of the cross-section and charge asymmetry of WW bosons produced in proton-proton collisions at s=8\sqrt{s}=8 TeV with the ATLAS detector

This paper presents measurements of the $W^+ \rightarrow \mu^+\nu$ and $W^- \rightarrow \mu^-\nu$ cross-sections and the associated charge asymmetry as a function of the absolute pseudorapidity of the decay muon. The data were collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with the ATLAS experiment at the LHC and correspond to a total integrated luminosity of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the 1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured with an uncertainty between 0.002 and 0.003. The results are compared with predictions based on next-to-next-to-leading-order calculations with various parton distribution functions and have the sensitivity to discriminate between them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables, submitted to EPJC. All figures including auxiliary figures are available at https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13

Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in √s=13 TeV pp collisions with the ATLAS detector

A search for supersymmetry through the pair production of electroweakinos with mass splittings near the electroweak scale and decaying via on-shell W and Z bosons is presented for a three-lepton final state. The analyzed proton-proton collision data taken at a center-of-mass energy of √s=13  TeV were collected between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider, corresponding to an integrated luminosity of 139  fb−1. A search, emulating the recursive jigsaw reconstruction technique with easily reproducible laboratory-frame variables, is performed. The two excesses observed in the 2015–2016 data recursive jigsaw analysis in the low-mass three-lepton phase space are reproduced. Results with the full data set are in agreement with the Standard Model expectations. They are interpreted to set exclusion limits at the 95% confidence level on simplified models of chargino-neutralino pair production for masses up to 345 GeV

Prototype ATLAS IBL Modules using the FE-I4A Front-End Readout Chip

The ATLAS Collaboration will upgrade its semiconductor pixel tracking detector with a new Insertable B-layer (IBL) between the existing pixel detector and the vacuum pipe of the Large Hadron Collider. The extreme operating conditions at this location have necessitated the development of new radiation hard pixel sensor technologies and a new front-end readout chip, called the FE-I4. Planar pixel sensors and 3D pixel sensors have been investigated to equip this new pixel layer, and prototype modules using the FE-I4A have been fabricated and characterized using 120 GeV pions at the CERN SPS and 4 GeV positrons at DESY, before and after module irradiation. Beam test results are presented, including charge collection efficiency, tracking efficiency and charge sharing.Comment: 45 pages, 30 figures, submitted to JINS

Search for squarks and gluinos in events with isolated leptons, jets and missing transverse momentum at s√=8 TeV with the ATLAS detector

The results of a search for supersymmetry in final states containing at least one isolated lepton (electron or muon), jets and large missing transverse momentum with the ATLAS detector at the Large Hadron Collider are reported. The search is based on proton-proton collision data at a centre-of-mass energy s√=8 TeV collected in 2012, corresponding to an integrated luminosity of 20 fb−1. No significant excess above the Standard Model expectation is observed. Limits are set on supersymmetric particle masses for various supersymmetric models. Depending on the model, the search excludes gluino masses up to 1.32 TeV and squark masses up to 840 GeV. Limits are also set on the parameters of a minimal universal extra dimension model, excluding a compactification radius of 1/R c = 950 GeV for a cut-off scale times radius (ΛR c) of approximately 30