123018842
Neutron capture on Zr-94 : Resonance parameters and Maxwellian-averaged cross sections
The neutron capture cross sections of the Zr isotopes play an important role in nucleosynthesis studies. The s-process reaction flow between the Fe seed and the heavier isotopes passes through the neutron magic nucleus {sup 90}Zr and through {sup 91,92,93,94}Zr, but only part of the flow extends to {sup 96}Zr because of the branching point at {sup 95}Zr. Apart from their effect on the s-process flow, the comparably small isotopic (n,{gamma}) cross sections make Zr also an interesting structural material for nuclear reactors. The {sup 94}Zr (n,{gamma}) cross section has been measured with high resolution at the spallation neutron source n{sub T}OF at CERN and resonance parameters are reported up to 60 keV neutron energy.
45106921
Proton scattering and the interacting boson model in the s-d shell.
The scattering cross sections of 29.4 MeV protons to the first five levels of the /sup 32/S and of 40 MeV protons to the first seven levels of /sup 24/Mg, have been analyzed. The calculations have been performed with a coupled-channel program using nuclear matrix elements obtained within the IBM approximation including g-boson configurations.
1115406
Spin formalism in the algebraic scattering theory for heavy ions.
We develop a simple method of treating spin effects in the frame of algebraic scattering theory and apply it to the system {sup 16}O+{sup 65}Cu at {ital E}{sub c.m.}=44.77 MeV.
29475570
Photon scattering by gamma -soft nuclei.
Calculations of elastic and inelastic photon scattering at energies around the giant dipole resonance are carried out for osmium isotopes in the SU(3)..-->..O(6) transitional region of the interacting boson model. /sup 186/Os shows features of a prolate nucleus, /sup 188en-dash192/Os that of ..gamma..-soft nuclei.
7587691
Isospin splitting of the giant dipole resonance in the s-d shell and the interacting boson model.
A phenomenological algebraic approach to nuclear isovector excitations is discussed within the framework of the interacting boson model. Analytic formulae are obtained for isospin splittings and excitation strengths of the giant dipole resonance in deformed nuclei. An application of the formalism to /sup 26/Mg is presented, where both schematic and realistic calculations have been performed.
39693462
Alpha-particle scattering and isoscalar giant resonances in the SU(3) model.
Giant isoscalar monopole and quadrupole resonances are introduced into the SU(3) limit of the interacting boson model by means of {ital S} and {ital D} bosons simulating collective particle-hole excitations, in addition to the usual {ital s} and {ital d} bosons, representing either collective particle or hole pairs in the valence shell. The evaluated giant resonance energies, as well as the matrix elements of {ital E}0 and {ital E}2 transitions from the giant resonance levels to the 0{sub 1}{sup +-}2{sub 1}{sup +-}4{sub 1}{sup +} members of the ground-state band, are utilized in coupled-channel calculations of giant resonance excitation through inelastic alpha scattering by the transitional isotopes {sup 148}Sm and {sup 154}Sm: the calculated differential cross sections are then compared with experimental data.
22148204
Implementation and performance of the third level muon trigger of the ATLAS experiment at LHC
The trigger system of the ATLAS experiment at the LHC aims at a high selectivity in order to keep the full physics potential while reducing the 40 MHz initial event rate imposed by the LHC bunch crossing down to /spl sim/100 Hz, as required by the data acquisition system. Algorithms working in the final stage of the trigger environment (Event Filter) are implemented to run both in a "wrapped" mode (reconstructing tracks in the entire Muon Spectrometer) and in a "seeded" mode (according to a dedicated strategy that performs pattern recognition only in regions of the detector where trigger hypotheses have been produced at earlier stages). The working principles of the offline muon reconstruction and identification algorithms (MOORE and MuId) implemented and used in the framework of the Event Filter are discussed in this paper. The reconstruction performance of these algorithms is presented for both modes in terms of efficiency, momentum resolution, rejection power and execution times on several samples of simulated single muon events, also taking into account the high background environment expected for ATLAS.
6222401
Implementation and performance of the seeded reconstruction for the ATLAS event filter
ATLAS is one of the four major Large Hadron Collider (LHC) experiments that will start data taking in 2007. It is designed to cover a wide range of physics topics. The ATLAS trigger system has to be able to reduce an initial 40 MHz event rate, corresponding to an average of 23 proton-proton inelastic interactions per every 25 ns bunch crossing, to 200 Hz admissible by the Data Acquisition System. The ATLAS trigger is divided in three different levels. The first one provides a signal describing an event signature using dedicated custom hardware. This signature must be confirmed by the High Level Trigger (HLT) which using commercial computing farms performs an event reconstruction by running a sequence of algorithms. The validity of a signature is checked after every algorithm execution. A main characteristic of the ATLAS HLT is that only the data in a certain window around the position flagged by the first level trigger are analyzed. In this work, the performance of one sequence that runs at the Event Filter level (third level) is demonstrated. The goal of this sequence is to reconstruct and identify high transverse momentum electrons by performing cluster reconstruction at the electromagnetic calorimeter, track reconstruction at the Inner Detector, and cluster track matching.
124822108
MUON RECONSTRUCTION AND IDENTIFICATION FOR THE EVENT FILTER OF THE ATLAS EXPERIMENT
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.
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.