RPCs as trigger detector for the ATLAS experiment: performances, simulation and application to the level-1 di-muon trigger

In the muon spectrometer different detectors are used to provide trigger functionality and precision momentum measurements. In the pseudorapidity range |eta|<1 the first level muon trigger is based on Resistive Plate Chambers, gas ionization detectors which are characterized by a fast response and an excellent time resolution (<1.5ns). The working principles of the Resistive Plate Chambers will be illustrated in chapter 3. Given the long time of operation expected for the ATLAS experiment (~10 years), ageing phenomena have been carefully studied, in order to ensure stable long-term operation of all the subdetectors. Concerning Resistive Plate Chambers, a very extensive ageing test has been performed at CERN's Gamma Irradiation Facility on three production chambers. The results of this test are presented in chapter 4. One of the most commonly used gases in RPCs operation is C2H2F4, which during the gas discharge can produce fluorine ions. Being F one of the most aggressive elements in nature, the presence of F- ions on the plate surface is dangerous for the integrity of the surface itself. For this reason a significant effort has been put in the last years to understand the mechanisms of F- production in RPCs operated with C2H2F4-based gas mixtures. The results of the measurements performed in the INFN-Roma2 ATLAS laboratories, in collaboration with the Dept. of Science and Chemical Technology of the Univeristy of Rome "Tor Vergata", are presented in chapter 5. The old Geant3 software toolkit, which has been the de facto standard for high energy physics simulation in the last 15 years, is being progressively replaced by the completely re-written toolkit Geant4. The migration from Geant3 to Geant4 has required, in the case of the ATLAS experiment, a re-writing from scratch of most of the simulation software. In chapter 6 the work done on RPC Geant4 simulation will be described. Many interesting physics processes to be observed in ATLAS will be characterized by the presence of pairs of muons in the final state. For this reason, the ATLAS first level muon trigger has been designed to allow to select di-muon events. While foreseen in the design of the trigger system, this possibility was never intensively tested with the final detector layout. In chapter 7 the first results of such a test will be summarized

Diversity of cervical microbiota in asymptomatic chlamydia trachomatis genital infection: a pilot study

Chlamydia trachomatis genital infection continues to be an important public health problem worldwide due to its increasing incidence. C. trachomatis infection can lead to severe sequelae, such as pelvic inflammatory disease, obstructive infertility, and preterm birth. Recently, it has been suggested that the cervico-vaginal microbiota may be an important defense factor toward C. trachomatis infection as well as the development of chronic sequelae. Therefore, the investigation of microbial profiles associated to chlamydial infection is of the utmost importance. Here we present a pilot study aiming to characterize, through the metagenomic analysis of sequenced 16s rRNA gene amplicons, the cervical microbiota from reproductive age women positive to C. trachomatis infection. The main finding of our study showed a marked increase in bacterial diversity in asymptomatic C. trachomatis positive women as compared to healthy controls in terms of Shannon's diversity and Shannon's evenness (P = 0.031 and P = 0.026, respectively). More importantly, the cervical microbiota from C. trachomatis positive women and from healthy controls significantly separated into two clusters in the weighted UniFrac analysis (P = 0.0027), suggesting that differences between the two groups depended entirely on the relative abundance of bacterial taxa rather than on the types of bacterial taxa present. Furthermore, C. trachomatis positive women showed an overall decrease in Lactobacillus spp. and an increase in anaerobes. These findings are part of an ongoing larger epidemiological study that will evaluate the potential role of distinct bacterial communities of the cervical microbiota in C. trachomatis infection

Geant4 Muon Digitization in the ATHENA Framework

The aim of this note is to describe the Muon Digitization software packages, completely re-written to run in the Athena framework and to interface with the Geant4 Muon Spectrometer simulation. The Muon Digitization is the simulation of the Raw Data Objects (RDO), or the electronic output, of the Muon Spectrometer. It consists of two steps: in the first step, the output of the detector simulation, the Muon Hits, is converted to Muon Digits, namely intermediate objects that can be fed into the reconstruction. In the second step, the Muon Digits are converted into RDO, the transient representation of raw data byte stream. We describe the detailed implementation of the first step of the Muon Digitization, where the detector simulation output is âﾜdigitizedâ into Muon Digits. We describe the fundamentals of the Muon Digitization algorithms, outlining their global structure and the infrastructure for the simulation of piled-up events. We also describe the details of the digitization validation procedures against the Monte Carlo information

Fast shower simulation in the ATLAS calorimeter

The time to simulate pp collisions in the ATLAS detector is largely dominated by the showering of electromagnetic particles in the heavy parts of the detector, especially the electromagnetic barrel and endcap calorimeters. Two procedures have been developed to accelerate the processing time of electromagnetic particles in these regions: (1) a fast shower parameterisation and (2) a frozen shower library. Both work by generating the response of the calorimeter to electrons and positrons with Geant 4, and then reintroduce the response into the simulation at runtime. In the fast shower parameterisation technique, a parameterisation is tuned to single electrons and used later by simulation. In the frozen shower technique, actual showers from low-energy particles are used in the simulation. Full Geant 4 simulation is used to develop showers down to ~1 GeV, at which point the shower is terminated by substituting a frozen shower. Judicious use of both techniques over the entire electromagnetic portion of the ATLAS calorimeter produces an important improvement of CPU time. We discuss the algorithms and their performance in this paper

Kaon physics with the KLOE detector

In this paper we discuss the recent finalized analyses by the KLOE experiment at DA$\Phi$NE: the CPT and Lorentz invariance test with entangled $K^0 \bar{K}^0$ pairs, and the precision measurement of the branching fraction of the decay ${ K^+} \rightarrow \pi^+\pi^-\pi^+(\gamma)$. We also present the status of an ongoing analysis aiming to precisely measure the $K^{\pm}$ mass

ATLAS Simulation readiness for first data at LHC

The commissioning phase for the ATLAS experiment, in preparation for the new LHC machine to switch on, has presented challenges to nearly every aspect of the software development. The ATLAS simulation program, as a part of this phase, is now operational and fully functional within the ATLAS common software framework, Athena. The latest developments are directed towards enhanced versatility to cope with the increasing needs of developers and users and ease of use for the large ATLAS community, now with more than 2000 potential users. Emphasis in this talk is on recently added functionality recently added, validation and production strategy, and improved robustness and maintainability