The Octant Module of the ATLAS Level-1 Muon to Central Trigger Processor Interface

The Muon to Central Trigger Processor Interface (MUCTPI) of the ATLAS Level-1 trigger receives data from the sector logic modules of the muon trigger at every bunch crossing and calculates the total multiplicity of muon candidates, which is then sent to the Central Trigger Processor where the final Level-1 decision is taken. The MUCTPI system consists of a 9U VME crate with a special backplane and 18 custom designed modules. We focus on the design and implementation of the octant module (MIOCT). Each of the 16 MIOCT modules processes the muon candidates from 13 sectors of one half-octant of the detector and forms the local muon candidate multiplicities for the trigger decision. It also resolves the overlaps between chambers in order to avoid double-counting of muon candidates that are detected in more than one sector. The handling of overlapping sectors is based on Look-Up-Tables (LUT) for maximum flexibility. The MIOCT also sends the information on the muon candidates over the custom backplane via the Readout Driver module to the Level-2 trigger and the DAQ systems when a Level-1 Accept is received. The design is based on state-of-the-art FPGA devices and special attention was paid to low-latency in the data transmission and processing

The ATLAS Level-1 Muon to Central Trigger Processor Interface

The Muon to Central Trigger Processor Interface (MUCTPI) is part of the ATLAS Level-1 trigger system and connects the output of muon trigger system to the Central Trigger Processor (CTP). At every bunch crossing (BC), the MUCTPI receives information on muon candidates from each of the 208 muon trigger sectors and calculates the total multiplicity for each of six transverse momentum (pT) thresholds. This multiplicity value is then sent to the CTP, where it is used together with the input from the Calorimeter trigger to make the final Level-1 Accept (L1A) decision. In addition the MUCTPI provides summary information to the Level-2 trigger and to the data acquisition (DAQ) system for events selected at Level-1. This information is used to define the regions of interest (RoIs) that drive the Level-2 muontrigger processing. The MUCTPI system consists of a 9U VME chassis with a dedicated active backplane and 18 custom designed modules. The design of the modules is based on state-of-the-art FPGA devices and special attention was paid to low-latency in the data transmission and processing. We present the design and implementation of the final version of the MUCTPI. A partially populated MUCTPI system is already installed in the ATLAS experiment and is being used regularly for commissioning tests and combined cosmic ray data taking runs

The Configuration System of the ATLAS Trigger

The ATLAS detector at CERN’s LHC will be exposed to proton-proton collisions at a rate of 40 MHz. To reduce the data rate to a manageable final output rate of 200Hz, only potentially interesting events are selected by a three-level trigger system. A system has been designed and implemented that enables the configuration of all three trigger levels from a centrally maintained relational database, for the purpose of both online data taking and offline trigger simulation. We present the current status of this trigger configuration system, covering the database design, client software and user interface tools, and putting emphasis on its multiple uses for data-taking, Monte-Carlo simulation, and trigger validation on express-stream data

Pentaquarks: review of the experimental evidence

Pentaquarks, namely baryons made by 4 quarks and one antiquark have been predicted and searched for since several decades without success. Theoretical and experimental advances in the last 2 years led to the observation of a number of pentaquark candidates. We review the experimental evidence for pentaquarks as well as their non-observations by some experiments, and discuss to which extend these sometimes contradicting informations may lead to a consistent picture.Comment: Contribution to the International Conference on 'Strangeness in Quark Matter', 15-21 Sept. 2004, Cape Tawn, South Afric

The TriggerTool Graphical User Interface to the ATLAS Trigger Configuration Database

A system has been designed and implemented to configure all three levels of the ATLAS trigger system from a centrally provided relational database, in which an archive of all trigger configurations used in data taking is also maintained. The user interaction with this database is via a Java-based graphical user interface known as the TriggerTool. We describe here how the TriggerTool has been designed to fulfill several different roles for users of varying expertise, from being a browser of the database to a tool for creating and modifying configuration

The ATLAS level-1 Central Trigger

The ATLAS Level-1 Central Trigger consists of the Muon-to-Central-Trigger-Processor Interface (MUCTPI), the Central Trigger Processor (CTP), and the Timing, Trigger and Control (TTC) partitions of the sub-detectors. The MUCTPI connects the output of the muon trigger system to the CTP. At every bunch crossing it receives information on muon candidates from each of the 208 muon trigger sectors and calculates the total multiplicity for each of six pT thresholds. The CTP combines information from the calorimeter trigger and the MUCTPI and makes the final Level-1 Accept (L1A) decision on the basis of lists of selection criteria (trigger menus). The MUCTPI and the CTP provide trigger summary information to the Level-2 trigger and to the data acquisition (DAQ) for every event selected at the Level-1. They further provide accumulated and, for the CTP, bunch-by-bunch counter data for monitoring of the trigger, detector and beam conditions. The TTC partitions send timing, trigger and control signals from the CTP to the sub-detectors and receive busy signals which can throttle the generation of L1As. The Local Trigger Processors (LTPs) normally receive the TTC signals from the CTP but can also generate them locally. The LTP interface (LTPIM) modules allow connecting of several LTPs for combined local running. The MUCTPI, the CTP and most of the TTC partitions of the ATLAS sub-detectors have been installed in the ATLAS experiment and are being used for commissioning tests with the trigger processors on the input and several sub-detectors as well as DAQ and Level-2 trigger on the output. Results of operating the Central Trigger in the experiment using trigger information from trigger processors connected to subdetectors observing cosmic rays will be shown

System Test of the ATLAS Muon Spectrometer in the H8 Beam at the CERN SPS

An extensive system test of the ATLAS muon spectrometer has been performed in the H8 beam line at the CERN SPS during the last four years. This spectrometer will use pressurized Monitored Drift Tube (MDT) chambers and Cathode Strip Chambers (CSC) for precision tracking, Resistive Plate Chambers (RPCs) for triggering in the barrel and Thin Gap Chambers (TGCs) for triggering in the end-cap region. The test set-up emulates one projective tower of the barrel (six MDT chambers and six RPCs) and one end-cap octant (six MDT chambers, A CSC and three TGCs). The barrel and end-cap stands have also been equipped with optical alignment systems, aiming at a relative positioning of the precision chambers in each tower to 30-40 micrometers. In addition to the performance of the detectors and the alignment scheme, many other systems aspects of the ATLAS muon spectrometer have been tested and validated with this setup, such as the mechanical detector integration and installation, the detector control system, the data acquisition, high level trigger software and off-line event reconstruction. Measurements with muon energies ranging from 20 to 300 GeV have allowed measuring the trigger and tracking performance of this set-up, in a configuration very similar to the final spectrometer. A special bunched muon beam with 25 ns bunch spacing, emulating the LHC bunch structure, has been used to study the timing resolution and bunch identification performance of the trigger chambers. The ATLAS first-level trigger chain has been operated with muon trigger signals for the first time

TESLA Technical Design Report Part III: Physics at an e+e- Linear Collider

The TESLA Technical Design Report Part III: Physics at an e+e- Linear ColliderComment: 192 pages, 131 figures. Some figures have reduced quality. Full quality figures can be obtained from http://tesla.desy.de/tdr. Editors - R.-D. Heuer, D.J. Miller, F. Richard, P.M. Zerwa

The relationships between West Nile and Kunjin viruses.

Until recently, West Nile (WN) and Kunjin (KUN) viruses were classified as distinct types in the Flavivirus genus. However, genetic and antigenic studies on isolates of these two viruses indicate that the relationship between them is more complex. To better define this relationship, we performed sequence analyses on 32 isolates of KUN virus and 28 isolates of WN virus from different geographic areas, including a WN isolate from the recent outbreak in New York. Sequence comparisons showed that the KUN virus isolates from Australia were tightly grouped but that the WN virus isolates exhibited substantial divergence and could be differentiated into four distinct groups. KUN virus isolates from Australia were antigenically homologous and distinct from the WN isolates and a Malaysian KUN virus. Our results suggest that KUN and WN viruses comprise a group of closely related viruses that can be differentiated into subgroups on the basis of genetic and antigenic analyses