53139097
Implementation and performance of the ATLAS trigger muon "vertical slice"
The ATLAS (A Toroidal LHC ApparatuS) trigger system is designed to keep high effiency for interesting events while achieving a rejection of low transverse momentum ( p T ) physics of about 10 7 , thus reaching the ∼200 Hz data storage capability of the Data Aquisition system. A three levels structure has been implemented for this purpose, as described in this work for the case of the muon trigger system. After describing the implementation, some performance results are presented in terms of final trigger rates, resolutions, efficiencies, background rejection and algorithm latency.
117068975
ATLAS RPC Quality Assurance results at INFN Lecce
The main results of the quality assurance tests performed on the Resistive Plate Chamber used by the ATLAS experiment at LHC as muon trigger chambers are reported and discussed. 
Since July 2004, about 270 RPC units has been certified at INFN Lecce site and delivered to CERN, for being integrated in the final muon station of the ATLAS barrel region. 
We show the key RPC characteristics which qualify the performance of this detector technology as muon trigger chamber in the harsh LHC enviroments. 
These are dark current, chamber efficiency, noise rate, gas volume tomography, and gas leakage.
116941153
Beyond Standard Model and Exotics: Experimental overview
124822108
MUON RECONSTRUCTION AND IDENTIFICATION FOR THE EVENT FILTER OF THE ATLAS EXPERIMENT
17810666
ATLAS RPC Cosmic Ray Teststand at INFN Lecce
We describe the design and functionality of the cosmic ray teststand built at 
INFN Lecce for ATLAS RPC quality control assurance.
123468882
Prospects for SUSY discovery based on inclusive searches with the ATLAS detector
The search for Supersymmetry (SUSY) among the possible scenarios of new physics is one of the most relevant goals of the ATLAS experiment running at CERN's Large Hadron Collider. In the present work the expected prospects for discovering SUSY with the ATLAS detector are reviewed, in particular for the first fb-1 of collected integrated luminosity. All studies and results reported here are based on inclusive search analyses realized with Monte Carlo signal and background data simulated through the ATLAS apparatus.
33472567
Measurement of the Sm-151(n, gamma) cross section from 0.6-eV to 1-MeV via the neutron time-of-flight technique at the CERN n_TOF facility
The {sup 151}Sm(n,{gamma}) cross section was measured with the time-of-flight technique from 0.6 eV up to 1 MeV relative to the Au standard with an overall uncertainty of typically 6%. Neutrons were produced by spallation at the innovative n{sub T}OF facility at CERN; the {gamma} rays from capture events were detected with organic C{sub 6}D{sub 6} scintillators. Experimental setup and data analysis procedures are described with emphasis on the corrections for detection efficiency, background subtraction, and neutron flux determination. At low energies, resonances could be resolved up to about 1 keV, yielding a resonance integral of 3575{+-}210 b, an average s-wave resonance spacing of =1.49{+-}0.07 eV, and a neutron strength function of =(3.87{+-}0.33)x10{sup -4}. Maxwellian-averaged capture cross sections are reported for thermal energies between 5 and 100 keV. These results are of relevance for nuclear structure studies, nuclear astrophysics, and nuclear technology. The new value of the Maxwellian-averaged cross section at kT=30 keV is 3.08{+-}0.15 b, considerably larger than previous theoretical estimates, and provides better constraints for the thermodynamic conditions during the occurrence of the slow neutron capture process in low-mass stars during their asymptotic giant branch phase.
34083016
The n_TOF Total Absorption Calorimeter for neutron capture measurements at CERN
The n_TOF Collaboration has built and commissioned a high-performance detector for (n, gamma) measurements called the Total Absorption Calorimeter (TAC). The TAC was especially designed for measuring neutron capture cross-sections of low-mass and/or radioactive samples with the accuracy required for nuclear technology and stellar nucleosynthesis. We present a detailed description of the TAC and discuss its overall performance in terms of energy and time resolution, background discrimination, detection efficiency and neutron sensitivity.
10349825
Mutual Heavy-Ion Dissociation in Peripheral Collisions at Ultrarelativistic Energies
We study mutual dissociation of heavy nuclei in peripheral collisions at ultrarelativistic energies. Earlier this process was proposed for beam luminosity monitoring via simultaneous registration of forward and backward neutrons in zero degree calorimeters at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory. Electromagnetic dissociation of heavy ions is considered in the framework of the Weizs\"acker-Williams method and simulated by the RELDIS code. Photoneutron cross sections measured in different experiments and calculated by the GNASH code are used as input for the calculations of dissociation cross sections. The difference in results obtained with different inputs provides a realistic estimation for the systematic uncertainty of the luminosity monitoring method. Contributions to simultaneous neutron emission due to grazing nuclear interactions is calculated within the abrasion model. A good description of the CERN SPS experimental data on Au and Pb dissociation gives confidence in the predictive power of the model for AuAu and PbPb collisions at the RHIC and the Large Hadron Collider at CERN.
123786004
Neutron physics of the Re/Os clock. III : Resonance analyses and stellar (n, gamma) cross sections of Os-186,Os-187,Os-188
Neutron resonance analyses have been performed for the capture cross sections of Os-186, Os-187, and Os-188 measured at the n_TOF facility at CERN. Resonance parameters have been extracted up to 5, 3, and 8 keV, respectively, using the SAMMY code for a full R-matrix fit of the capture yields. From these results average resonance parameters were derived by a statistical analysis to provide a comprehensive experimental basis for modeling of the stellar neutron capture rates of these isotopes in terms of the Hauser-Feshbach statistical model. Consistent calculations for the capture and inelastic reaction channels are crucial for the evaluation of stellar enhancement factors to correct the Maxwellian averaged cross sections obtained from experimental data for the effect of thermally populated excited states. These factors have been calculated for the full temperature range of current scenarios of s-process nucleosynthesis using the combined information of the experimental data in the region of resolved resonances and in the continuum. The consequences of this analysis for the s-process component of the Os-187 abundance and the related impact on the evaluation of the time duration of galactic nucleosynthesis via the Re/Os cosmochronometer are discussed.
21048421
Electromagnetically induced nuclear-charge pickup observed in ultrarelativistic Pb collisions.
A strong increase of inclusive nuclear-charge pickup cross sections, forming 83Bi from 158A GeV 82Pb ions, is observed in comparison to similar measurements at 10.6A GeV. From the dependence of these cross sections on target atomic number, this increase is attributed to the electromagnetic process of pion production by equivalent photons. The observed cross sections can be reproduced quantitatively using the recently developed RELDIS code.