CMS Barrel Pixel Detector Overview

The pixel detector is the innermost tracking device of the CMS experiment at the LHC. It is built from two independent sub devices, the pixel barrel and the end disks. The barrel consists of three concentric layers around the beam pipe with mean radii of 4.4, 7.3 and 10.2 cm. There are two end disks on each side of the interaction point at 34.5 cm and 46.5 cm. This article gives an overview of the pixel barrel detector, its mechanical support structure, electronics components, services and its expected performance.Comment: Proceedings of Vertex06, 15th International Workshop on Vertex Detector

Measurement of D* Meson Cross Sections at HERA and Determination of the Gluon Density in the Proton using NLO QCD

With the H1 detector at the ep collider HERA, D* meson production cross sections have been measured in deep inelastic scattering with four-momentum transfers Q^2>2 GeV2 and in photoproduction at energies around W(gamma p)~ 88 GeV and 194 GeV. Next-to-Leading Order QCD calculations are found to describe the differential cross sections within theoretical and experimental uncertainties. Using these calculations, the NLO gluon momentum distribution in the proton, x_g g(x_g), has been extracted in the momentum fraction range 7.5x10^{-4}< x_g <4x10^{-2} at average scales mu^2 =25 to 50 GeV2. The gluon momentum fraction x_g has been obtained from the measured kinematics of the scattered electron and the D* meson in the final state. The results compare well with the gluon distribution obtained from the analysis of scaling violations of the proton structure function F_2.Comment: 27 pages, 9 figures, 2 tables, submitted to Nucl. Phys.

Technical design of the phase I Mu3e experiment

The Mu3e experiment aims to find or exclude the lepton flavour violating decay $\mu \rightarrow eee$ at branching fractions above $10^{-16}$. A first phase of the experiment using an existing beamline at the Paul Scherrer Institute (PSI) is designed to reach a single event sensitivity of $2\cdot 10^{-15}$. We present an overview of all aspects of the technical design and expected performance of the phase~I Mu3e detector. The high rate of up to $10^{8}$ muon decays per second and the low momenta of the decay electrons and positrons pose a unique set of challenges, which we tackle using an ultra thin tracking detector based on high-voltage monolithic active pixel sensors combined with scintillating fibres and tiles for precise timing measurements.Comment: 114 pages, 185 figures. Submitted to Nuclear Instruments and Methods A. Edited by Frank Meier Aeschbacher This version has many enhancements for better readability and more detail

Technical design of the phase I Mu3e experiment

The Mu3e experiment aims to find or exclude the lepton flavour violating decay μ→eee at branching fractions above 10−16. A first phase of the experiment using an existing beamline at the Paul Scherrer Institute (PSI) is designed to reach a single event sensitivity of 2⋅10−15. We present an overview of all aspects of the technical design and expected performance of the phase I Mu3e detector. The high rate of up to 108 muon decays per second and the low momenta of the decay electrons and positrons pose a unique set of challenges, which we tackle using an ultra thin tracking detector based on high-voltage monolithic active pixel sensors combined with scintillating fibres and tiles for precise timing measurements

Towards a dynamic earthquake risk framework for Switzerland

Scientists from different disciplines at ETH Zurich are developing a dynamic, harmonised, and user-centred earthquake risk framework for Switzerland, relying on a continuously evolving earthquake catalogue generated by the Swiss Seismological Service (SED) using the national seismic networks. This framework uses all available information to assess seismic risk at various stages and facilitates widespread dissemination and communication of the resulting information. Earthquake risk products and services include operational earthquake (loss) forecasting (OE(L)F), earthquake early warning (EEW), ShakeMaps, rapid impact assessment (RIA), structural health monitoring (SHM), and recovery and rebuilding efforts (RRE). Standardisation of products and workflows across various applications is essential for achieving broad adoption, universal recognition, and maximum synergies. In the Swiss dynamic earthquake risk framework, the harmonisation of products into seamless solutions that access the same databases, workflows, and software is a crucial component. A user-centred approach utilising quantitative and qualitative social science tools like online surveys and focus groups is a significant innovation featured in all products and services. Here we report on the key considerations and developments of the framework and its components. This paper may serve as a reference guide for other countries wishing to establish similar services for seismic risk reduction.</p

Development of an Indium Bump Bond Process for Silicon Pixel Detectors at PSI

The hybrid pixel detectors used in the high energy physics experiments currently under construction use a three dimensional connection technique, the so-called bump bonding. As the pitch below 100um, required in these applications, cannot be fullfilled with standard industrial processes (e.g. the IBM C4 process), an in-house bump bond process using reflown indium bumps was developed at PSI as part of the R&D for the CMS-pixel detector. The bump deposition on the sensor is performed in two subsequent lift-off steps. As the first photolithographic step a thin under bump metalization (UBM) is sputtered onto bump pads. It is wettable by indium and defines the diameter of the bump. The indium is evaporated via a second photolithographic step with larger openings and is reflown afterwards. The height of the balls is defined by the volume of the indium. On the readout chip only one photolithographic step is carried out to deposit the UBM and a thin indium layer for better adhesion. After mating both parts a second reflow is performed for self alignment and obtaining a high mechanical strength. For the placement of the chips a manual and an automatic machine was constructed. The former is very flexible in handling different chip and module geometries but has a limited throughput while the latter features a much higher grade of automatisation and is therefore much more suited for producing hundreds of modules with a well defined geometry. The reliability of this process was proven by the successful construction of the PILATUS detector. The construction of PILATUS 6M (60 modules) and the CMS pixel barrel (roughly 800 modules) will start in 2005

Synovial C-reactive protein features high negative predictive value but is not useful as a single diagnostic parameter in suspected periprosthetic joint infection (PJI)

OBJECTIVES Synofluid C-reactive protein (syCRP) has been recently described as a new biomarker in preoperative diagnostics to identify periprosthetic joint infections (PJI). The aim of this study was to evaluate syCRP in a large cohort of patients with suspected PJI and to calculate the optimal cut-off to diagnose PJI. METHODS Between September 2015 and June 2017, we prospectively included patients with suspected PJI, in which syCRP was additionally measured along with routine preoperative diagnostic serum and synovial biomarkers. We analysed the sensitivity and specificity of syCRP using receiver operating characteristic curves. RESULTS We included 192 cases (hip n = 80, knee n = 91, shoulder n = 21) with a final diagnosis of PJI in 26 cases (14.0%). Combined for all joints, the syCRP values were significantly higher in the PJI group than in the no PJI group (median: 13.8 vs. 0 mg/l; p < 0.001). The optimal cut-off (Youden Index: 0.71) for the PJI diagnosis combined for all joints was at a syCRP value of 2.9 mg/l with a sensitivity of 88%, a specificity of 82%, and a negative predictive value of 98%. CONCLUSIONS SyCRP features high negative predictive value but is not useful as a single diagnostic parameter in suspected periprosthetic joint infection (PJI)