ATLAS Pixel Detector status in Run 2

The ATLAS Pixel Detector had good performance throughout the first operation of the LHC. During the long shutdown of data taking in 2013 and 2014, the services of the detector have been renovated and a fourth layer of pixels, called Insertable B-Layer (IBL), has been placed around new smaller radius beampipe. The new layer is closer to the interaction point and has a reduced pixel size. It will mitigate some loss of efficiency of the previous innermost layer when increasing the peak luminosity, scheduled to reach 2×1034 cm−2 s−1. The modules production has been completed in the first months of 2014. An overview of the used Technologies and the expected performance of the Pixel Detector is presented

Evaluation of basal ganglia haemodynamic changes with perfusion-weighted magnetic resonance imaging in patients with Parkinson's disease

The aim of our study was to assess the regional cerebral blood flow (rCBF) of basal ganglia and thalami in patients with Parkinson’s disease (PD) using perfusion–weighted magnetic resonance imaging (PW–MRI)

Some new results on a Lavrentieff phenomenon for problems of homogenization with constraints on the gradient

In this paper we analyze, in the context of a Lavrentieff phenomenon, the process of homogenization for Dirichlet problems

Asymptotics of Eigenvalues and Eigenfunctions for the Laplace Operator in a Domain with Oscillating Boundary. Multiple Eigenvalue Case

We study the asymptotic behavior of the solutions of a spectral problem for the Laplacian in a domain with rapidly oscillating boundary. We consider the case where the eigenvalue of the limit problem is multiple. We construct the leading terms of the asymptotic expansions for the eigenelements and verify the asymptotics

Test with high-energy and high-intensity proton beam on ATLAS silicon detectors towards HL-LHC

The ATLAS silicon tracker was designed to sustain a high level of dose integrated over several years of LHC operations. The radiation tolerance should nevertheless guarantee the survival of the detector in the case of accidental beam loss. In 2006, an experiment performed on an ATLAS Pixel module established that they are able to sustain beam losses in the order of 1.5 × 1010 protons/cm2 with a minimal or no performance degradation. Recently, a new experiment was performed with a higher-intensity and -energy proton beam on two IBL Pixel modules and one ITk strip in the HiRadMat area at CERN. Preliminary results are presented along with perspectives of 2018 test beams

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