A Complete Set of Firmware for the TileCal Read-Out Driver

TileCal is the hadronic tile calorimeter of the ATLAS experiment at LHC/CERN. The Read-Out Driver (ROD) is the main component of the TileCal back-end electronics. The ROD is a VME 64x 9u board with multiple programmable devices which requires a complete set of firmware. This paper describes the firmware and functionalities of all these programmable devices, especially the DSP Processing Units daughterboards where the data processing takes place

Optical Buffer 1:16

This document is a manual describing the functionality and the operation of the Optical Buffer 1:16 (OB). The OB was specially designed to repeat optical signals during the TileCal Read-Out drivers (ROD) production. The data generated in one Optical Multiplexer Board (OMB) 6U prototypes were repeated with two OB in order to inject data simultaneously to four RODs

Monte Carlo Performance of the TileCal Low pT Muon Identification Algorithm

This note describes the TileCal standalone low pT muon identification algorithm (TileMuId) developed to contribute to the Level-2 trigger. This algorithm is based on the characteristic muon energy deposition inside the calorimeter. The implementation of this algorithm in the core of the Digital Signal Processors (DSPs) in the TileCal Read-Out Drivers (RODs) is also discussed in this paper. The TileMuId performance with Monte Carlo data from single muons and bb events is shown in terms of efficiencies and fraction of fakes for both a fully Level-2 version and a ROD-based version of the algorithm

Status of the Optical Multiplexer Board 9U Prototype

This paper presents the architecture and the status of the Optical Multiplexer Board (OMB) 9U for the ATLAS/LHC Tile hadronic calorimeter (TileCal). This board will analyze the front-end data CRC to prevent bit and burst errors produced by radiation. Besides, due to its position within the data acquisition chain it will be used to emulate front-end data for tests. The first two prototypes of the final OMB 9U version have been produced at CERN. Detailed design issues and manufacture features of these prototypes are described. Functional descriptions of the board on its two main operation modes as CRC checking and data ROD injector are explained as well as other functionalities. Finally, the schedule for next year when the production of the OMB will be take place is also presented

Setup, tests and results for the ATLAS TileCal Read Out Driver production

In this paper we describe the performance and test results of the production of the 38 ATLAS TileCal Read Out Drivers (RODs). We first describe the basic hardware specifications and firmware functionality of the modules, the test-bench setup used for production and the test procedure to qualify the boards. We then finally show and discuss the performance results

Search for composite and exotic fermions at LEP 2

A search for unstable heavy fermions with the DELPHI detector at LEP is reported. Sequential and non-canonical leptons, as well as excited leptons and quarks, are considered. The data analysed correspond to an integrated luminosity of about 48 pb^{-1} at an e^+e^- centre-of-mass energy of 183 GeV and about 20 pb^{-1} equally shared between the centre-of-mass energies of 172 GeV and 161 GeV. The search for pair-produced new leptons establishes 95% confidence level mass limits in the region between 70 GeV/c^2 and 90 GeV/c^2, depending on the channel. The search for singly produced excited leptons and quarks establishes upper limits on the ratio of the coupling of the excited fermio

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

Standalone vertex finding in the ATLAS muon spectrometer

A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011

Measurement of inclusive two-particle angular correlations in pp collisions with the ATLAS detector at the LHC

We present a measurement of two-particle angular correlations in proton- proton collisions at s√=900 GeV and 7 TeV. The collision events were collected during 2009 and 2010 with the ATLAS detector at the Large Hadron Collider using a single-arm minimum bias trigger. Correlations are measured for charged particles produced in the kinematic range of transverse momentum p T  > 100 MeV and pseudorapidity |η| < 2.5. A complex structure in pseudorapidity and azimuth is observed at both collision energies. Results are compared to pythia 8 and herwig++ as well as to the AMBT2B, DW and Perugia 2011 tunes of pythia 6. The data are not satisfactorily described by any of these models