Multiplicity Dependence of Two-Particle Correlations in Proton-Proton Collisions Measured with ALICE at the LHC

We investigate properties of jets in proton-proton collisions using two-particle angular correlations. By choosing an analysis approach based on two-particle angular correlations, also the properties of low-energetic jets can be accessed. Observing the strength of the correlation as a function of the charged particle multiplicity reveals jet fragmentation properties as well as the contribution of jets to the overall charged particle multiplicity. Furthermore, the analysis discloses information on the underlying multiple parton interactions. We present results from proton-proton collisions at the center-of-mass energies $\sqrt{s}$ = 0.9, 2.76, and 7.0 TeV recorded by the ALICE experiment. The ALICE data are compared to Pythia6, Pythia8, and Phojet simulations.Comment: To appear in the proceedings of the 24th Rencontres de Blois, Particle Physics and Cosmology, 2012, 4 pages, 8 figure

Multiplicity dependence of two-particle angular correlations in proton-proton collisions measured with ALICE at the LHC

Die Arbeit untersucht Di-Jets in hochenergetischen Proton-Proton-Kollisionen, die am LHC (Large Hadron Collider) des Forschungzentrums CERN mit dem ALICE (A Large Ion Collider Experiment) Detektor aufgezeichnet wurden. Mit Hilfe der Methode der Zwei-Teilchen-Winkelkorrelation konnten Jet-Eigenschaften bei sehr geringen Jet-Energien untersucht werden. Die Ergebnisse der vorgestellten Datenanalyse ermöglichen es, die Parametrisierung der Jet-Fragmentation in theoretischen Modellen im niederenergetischen Bereich zu optimieren, in dem keine störungstheoretische Behandlung der Quantenchromodynamik möglich ist. Aus den Ergebnissen können außerdem Informationen über Multi-Partoninteraktionen in Proton-Proton-Kollisionen abgeleitet werden

Toxin-vermittelte Ablation glomerulärer parietaler Epithelzellen im Mausmodell

Akute glomeruläre Schädigungen gehen häufig mit einer pathologischen Proliferartion von Zellen innerhalb der glomerulären Kapsel einher, die schließlich in der Entstehung einer Niereninsuffizienz mündet. Vor allem bei der fokalen segmentalen Glomerulosklerose (FSGS) und der rasch progressiven Glomerulonephritis (RPGN) stellen diese pathologischen Proliferationen einen pathognomonischen Befund dar. Viele wissenschaftliche Untersuchungen der letzten Jahre versuchten, die Frage nach dem entsprechenden Auslöser für die Entstehung dieser Erkrankungen zu beantworten. So standen neben den Mesangialzellen auch die viszeralen Epithelzellen des Glomerulum, die Podozyten, im Fokus der Forschung. In jüngeren Studien konnte jedoch gezeigt werden, dass die Proliferate vor allem aus parietalen Epithelzellen (PECs) bestehen. In der vorliegenden Studie wurde durch Kreuzung von PEC-rtTA/LC1-Mäusen mit ROSADTA176 Mäusen erstmalig ein Mausmodell generiert, das Doxyzyklin-induzierbar ein attenuiertes Diphtherietoxin (DTA176) spezifisch in PECs exprimiert und so deren Zelltod herbeiführt.Acute glomerular lesions are often associated with pathological proliferartion of cells within the glomerular capsule, which finally leads to the formation of renal insufficiency. Especially in focal segmental glomerulosclerosis (FSGS) and the rapidly progressive glomerulonephritis (RPGN) these pathological proliferations are a pathognomonic finding. In recent years many scientific studies aimed to answer the question of the trigger for these diseases. Initially the mesangial cell as well as the visceral epithelial cell of the glomerulus, the podocyte, was in the focus of research. Parietal epithelial cells (PECs) just recently received an increasing amount of attention because of the fact, that they represent the largest population of cells involved in the proliferations in RPGN. In the present study, a transgenic system was used to ablate PECs in a doxycycline inducible fashion. For this purpose a novel transgenic system was developed in which expression of an attenuated DTA (diphtheria toxin) was irreversibly activated upon Cre recombination within the target cells

Isothermal annealing of radiation defects in bulk material of diodes from 8" silicon wafers

The high luminosity upgrade of the LHC will provide unique physics opportunities, such as the observation of rare processes and precision measurements. However, the accompanying harsh radiation environment will also pose unprecedented challenged to the detector performance and hardware. In this paper, we study the radiation induced damage and its macroscopic isothermal annealing behaviour of the bulk material from new 8" silicon wafers using diode test structures. The sensor properties are determined through measurements of the diode capacitance and leakage current for three thicknesses, two material types, and neutron fluences from $6.5\cdot 10^{14}$ to $10^{16}\,\mathrm{neq/cm^2}$.Comment: 15 pages, 11 Figure

The Compact Linear Collider (CLIC) - 2018 Summary Report

The Compact Linear Collider (CLIC) is a TeV-scale high-luminosity linear e+e- collider under development at CERN. Following the CLIC conceptual design published in 2012, this report provides an overview of the CLIC project, its current status, and future developments. It presents the CLIC physics potential and reports on design, technology, and implementation aspects of the accelerator and the detector. CLIC is foreseen to be built and operated in stages, at centre-of-mass energies of 380 GeV, 1.5 TeV and 3 TeV, respectively. CLIC uses a two-beam acceleration scheme, in which 12 GHz accelerating structures are powered via a high-current drive beam. For the first stage, an alternative with X-band klystron powering is also considered. CLIC accelerator optimisation, technical developments and system tests have resulted in an increased energy efficiency (power around 170 MW) for the 380 GeV stage, together with a reduced cost estimate at the level of 6 billion CHF. The detector concept has been refined using improved software tools. Significant progress has been made on detector technology developments for the tracking and calorimetry systems. A wide range of CLIC physics studies has been conducted, both through full detector simulations and parametric studies, together providing a broad overview of the CLIC physics potential. Each of the three energy stages adds cornerstones of the full CLIC physics programme, such as Higgs width and couplings, top-quark properties, Higgs self-coupling, direct searches, and many precision electroweak measurements. The interpretation of the combined results gives crucial and accurate insight into new physics, largely complementary to LHC and HL-LHC. The construction of the first CLIC energy stage could start by 2026. First beams would be available by 2035, marking the beginning of a broad CLIC physics programme spanning 25-30 years

Isothermal annealing of radiation defects in silicon bulk material of diodes from 8” silicon wafers

The high luminosity upgrade of the LHC will provide unique physics opportunities, such as the observation of rare processes and precision measurements. However, the accompanying harsh radiation environment will also pose unprecedented challenged to the detector performance and hardware. In this paper, we study the radiation induced damage and its macroscopic isothermal annealing behaviour of the bulk material from new 8" silicon wafers using diode test structures. The sensor properties are determined through measurements of the diode capacitance and leakage current for three thicknesses, two material types, and neutron fluences from 6.5 · 10$^{14}$ to 1 · 10$^{16}$ n$_{eq}$/cm$^2$