124822108
MUON RECONSTRUCTION AND IDENTIFICATION FOR THE EVENT FILTER OF THE ATLAS EXPERIMENT
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.
120117626
Coexistence of Cluster Configurations in the 32S Nucleus
115178117
Reflectionless PT-Symmetric Potentials in the One-dimensional Dirac Equation
We study the one-dimensional Dirac equation with local -symmetric potentials whose discrete eigenfunctions and continuum asymptotic eigenfunctions are eigenfunctions of the operator, too: on these conditions, the bound-state spectra are real and the potentials are reflectionless and conserve unitarity in the scattering process. The absence of reflection makes it meaningful to consider also -symmetric potentials that do not vanish asymptotically.
118535533
New description of the doublet bands in doubly odd nuclei
The experimentally observed {delta}I=1 doublet bands in some odd-odd nuclei are analyzed within the orthosymplectic extension of the interacting vector boson model (IVBM). A new, purely collective interpretation of these bands is given on the basis of the obtained boson-fermion dynamical symmetry of the model. It is illustrated by its application to three odd-odd nuclei from the A{approx}130 region, namely {sup 126}Pr, {sup 134}Pr, and {sup 132}La. The theoretical predictions for the energy levels of the doublet bands as well as E2 and M1 transition probabilities between the states of the yrast band in the last two nuclei are compared with experiment and the results of other theoretical approaches. The obtained results reveal the applicability of the orthosymplectic extension of the IVBM.
121284029
The measurement of the Pb-206 (n, gamma) cross section and stellar implications
The neutron capture cross section of 206Pb has been measured at the CERN n\TOF spectrometer using a setup of two C6D6 detectors. In the energy interval from 1 eV to 600 keV the cross section is dominated by resonances, which were analyzed via the R-matrix analysis code SAMMY. In the relevant energy ranges for stellar nucleosynthesis, i.e., at thermal energies of kT = 8 keV and kT = 23 keV, the present Maxwellian average cross section differs by 20% and 9% from the recommended values of Bao et al respectively. From the new cross section the s-abundance of 206Pb could be reliably determined as 70(4)%. This result is of importance in order to test and constrain r-process abundance calculations in the actinide region, because the r-process portion of 206Pb is dominated by α-back decays of short-lived transbismuth isotopes.
37166453
Neutron Capture Cross Section of 90Zr: Bottleneck in the s-Process Reaction Flow
The neutron capture cross sections of the Zr isotopes have important implications in nuclear astrophysics and 
for reactor design. The small cross section of the neutron magic nucleus 90Zr, which accounts for more than 50% 
of natural zirconium represents one of the key isotopes for the stellar s-process, because it acts as a bottleneck 
in the neutron capture chain between the Fe seed and the heavier isotopes. The same element, Zr, also is an 
important component of the structural materials used in traditional and advanced nuclear reactors. The (n, γ ) 
cross section has been measured at CERN, using the n TOF spallation neutron source. In total, 45 resonances 
could be resolved in the neutron energy range below 70 keV, 10 being observed for the first time thanks to the 
high resolution and low backgrounds at n TOF. On average, the γ widths obtained in resonance analyses with 
the R-matrix code SAMMY were 15% smaller than reported previously. By these results, the accuracy of the 
Maxwellian averaged cross section for s-process calculations has been improved by more than a factor of 2.