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T. Wengler

Publications and source records attributed to T. Wengler.

8 recordsLinked to original sources
arXiv2020

CentOS Linux for the ATLAS MUCTPI Upgrade

A new Muon-to-Central-Trigger Processor Interface (MUCTPI) was built as part of the upgrade of the ATLAS Level-1 trigger system for the next Run of the Large Hadron Collider at CERN. The MUCTPI has 208 high-speed optical serial links for receiving muon candidates from the muon trigger detectors. Three high-end FPGAs are used for real-time processing of the muon candidates, for sending trigger information to other parts of the trigger system, and for sending summary information to the data acquisition and monitoring system. A System-on-Chip (SoC) is used for the control, configuration and monitoring of the hardware and the operation of the MUCTPI. The SoC consists of an FPGA part and a processor system. The FPGA part provides communication with the processing FPGAs, while the processor system runs software for communication with the run-control system of the ATLAS experiment. In this paper we will describe our experience with running CentOS Linux on the SoC. Cross-compilation together with the existing framework for building of the ATLAS trigger and data acquisition (TDAQ) software is being used in order to allow the deployment of the TDAQ software directly on the SoC.

physics.ins-det↗
arXiv2009

The FP420 R&D Project: Higgs and New Physics with forward protons at the LHC

We present the FP420 R&D project, which has been studying the key aspects of the development and installation of a silicon tracker and fast-timing detectors in the LHC tunnel at 420 m from the interaction points of the ATLAS and CMS experiments. These detectors would measure precisely very forward protons in conjunction with the corresponding central detectors as a means to study Standard Model (SM) physics, and to search for and characterise New Physics signals. This report includes a detailed description of the physics case for the detector and, in particular, for the measurement of Central Exclusive Production, pp --> p + phi + p, in which the outgoing protons remain intact and the central system phi may be a single particle such as a SM or MSSM Higgs boson. Other physics topics discussed are gamma-gamma and gamma-p interactions, and diffractive processes. The report includes a detailed study of the trigger strategy, acceptance, reconstruction efficiencies, and expected yields for a particular p p --> p H p measurement with Higgs boson decay in the b-bbar mode. The document also describes the detector acceptance as given by the LHC beam optics between the interaction points and the FP420 location, the machine backgrounds, the new proposed connection cryostat and the moving ("Hamburg") beam-pipe at 420 m, and the radio-frequency impact of the design on the LHC. The last part of the document is devoted to a description of the 3D silicon sensors and associated tracking performances, the design of two fast-timing detectors capable of accurate vertex reconstruction for background rejection at high-luminosities, and the detector alignment and calibration strategy.

hep-ex↗
arXiv2006

Determination of the strong coupling constant at LEP

Multi-hadronic events produced in e+e- collisions provide an excellent laboratory to study QCD, the theory of strong interactions, and in particular to determine the strong coupling parameter alpha_s and demonstrate its predicted behavior as a function of the energy scale. Determinations of alpha_s at LEP will be reviewed with emphasis on event shape variables and jet rates in 3-jet and 4-jet events.

hep-ex↗
arXiv2006

A configuration system for the ATLAS trigger

The ATLAS detector at CERN's Large Hadron Collider will be exposed to proton-proton collisions from beams crossing at 40 MHz that have to be reduced to the few 100 Hz allowed by the storage systems. A three-level trigger system has been designed to achieve this goal. We describe the configuration system under construction for the ATLAS trigger chain. It provides the trigger system with all the parameters required for decision taking and to record its history. The same system configures the event reconstruction, Monte Carlo simulation and data analysis, and provides tools for accessing and manipulating the configuration data in all contexts.

physics.ins-det↗
arXiv2004

Physics at the CLIC Multi-TeV Linear Collider

This report summarizes a study of the physics potential of the CLIC e+e- linear collider operating at centre-of-mass energies from 1 TeV to 5 TeV with luminosity of the order of 10^35 cm^-2 s^-1. First, the CLIC collider complex is surveyed, with emphasis on aspects related to its physics capabilities, particularly the luminosity and energy, and also possible polarization, γγand e-e- collisions. The next CLIC Test facility, CTF3, and its R&D programme are also reviewed. We then discuss aspects of experimentation at CLIC, including backgrounds and experimental conditions, and present a conceptual detector design used in the physics analyses, most of which use the nominal CLIC centre-of-mass energy of 3 TeV. CLIC contributions to Higgs physics could include completing the profile of a light Higgs boson by measuring rare decays and reconstructing the Higgs potential, or discovering one or more heavy Higgs bosons, or probing CP violation in the Higgs sector. Turning to physics beyond the Standard Model, CLIC might be able to complete the supersymmetric spectrum and make more precise measurements of sparticles detected previously at the LHC or a lower-energy linear e+e- collider: γγcollisions and polarization would be particularly useful for these tasks. CLIC would also have unique capabilities for probing other possible extensions of the Standard Model, such as theories with extra dimensions or new vector resonances, new contact interactions and models with strong WW scattering at high energies. In all the scenarios we have studied, CLIC would provide significant fundamental physics information beyond that available from the LHC and a lower-energy linear e+e- collider, as a result of its unique combination of high energy and experimental precision.

hep-ph↗
arXiv1999

Hadronization Corrections to Jet Cross Sections in Deep-Inelastic Scattering

The size of non-perturbative corrections to high E_T jet production in deep-inelastic scattering is reviewed. Based on predictions from fragmentation models, hadronization corrections for different jet definitions are compared and the model dependence as well as the dependence on model parameters is investigated. To test whether these hadronization corrections can be applied to next-to-leading order (NLO) calculations, jet properties and topologies in different parton cascade models are compared to those in NLO. The size of the uncertainties in estimating the hadronization corrections is compared to the uncertainties of perturbative predictions. It is shown that for the inclusive k_\perp ordered jet clustering algorithm the hadronization corrections are smallest and their uncertainties are of the same size as the uncertainties of perturbative NLO predictions.

hep-ph↗
arXiv1998

Forward pi^0 -Meson and Charged Particle Production in Deep Inelastic Scattering at low Bjorken-x

High transverse momentum pi^0 -mesons and charged particles are measured in deep inelastic e-p scattering events at low Bjorken-x taken with the H1 detector at HERA. The production of high-pt particles is strongly correlated to the emission of hard partons in QCD and is therefore sensitive to the dynamics of the strong interaction. For the first time the measurement of single particles has been extended to the region of small angles w.r.t. the proton remnant (forward region). This region is expected to be particularly sensitive to QCD evolution effects in final states. Results are presented as a function of Bjorken-x and x_i, the fraction of the incident proton's energy carried by the particle, and are compared to different QCD models.

hep-ex↗