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Author LHCf Collaboration (Adriani, O. et al); Faus-Golfe, A.; Velasco, J.
Title Measurement of zero degree single photon energy spectra for sqrt(s) = 7 TeV proton-proton collisions at LHC Type Journal Article
Year (down) 2011 Publication Physics Letters B Abbreviated Journal Phys. Lett. B
Volume 703 Issue 2 Pages 128-134
Keywords LHC; Ultra-high energy cosmic-ray; Hadron interaction models
Abstract In early 2010. the Large Hadron Collider forward (LHCf) experiment measured very forward neutral particle spectra in LHC proton-proton collisions. From a limited data set taken under the best beam conditions (low beam-gas background and low occurrence of pile-up events), the single photon spectra at root s = 7 TeV and pseudo-rapidity (eta) ranges from 8.81 to 8.99 and from 10.94 to infinity were obtained for the first time and are reported in this Letter. The spectra from two independent LHCf detectors are consistent with one another and serve as a cross check of the data. The photon spectra are also compared with the predictions of several hadron interaction models that are used extensively for modeling ultra-high energy cosmic-ray showers. Despite conservative estimates for the systematic errors, none of the models agree perfectly with the measurements. A notable difference is found between the data and the DPMJET 3.04 and PYTHIA 8.145 hadron interaction models above 2 TeV where the models predict higher photon yield than the data. The QGSJET II-03 model predicts overall lower photon yield than the data, especially above 2 TeV in the rapidity range 8.81 < eta < 8.99.
Address [Fukatsu, K; Itow, Y; Kawade, K; Mase, T; Masuda, K; Matsubara, Y; Mitsuka, G; Muraki, Y; Sako, T; Suzuki, K; Taki, K] Nagoya Univ, Solar Terr Environm Lab, Nagoya, Aichi 4648601, Japan, Email: sako@stelab.nagoya-u.ac.jp
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-2693 ISBN Medium
Area Expedition Conference
Notes WOS:000295105500005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 769
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Author Pierre Auger Collaboration (Abreu, P. et al); Pastor, S.
Title The Lateral Trigger Probability function for the Ultra-High Energy Cosmic Ray showers detected by the Pierre Auger Observatory Type Journal Article
Year (down) 2011 Publication Astroparticle Physics Abbreviated Journal Astropart Phys.
Volume 35 Issue 5 Pages 266-276
Keywords Ultra-High Energy Cosmic Rays; Pierre Auger Observatory; Extensive Air Showers; Trigger performance; Surface detector; Hybrid detector
Abstract In this paper we introduce the concept of Lateral Trigger Probability (LTP) function, i.e., the probability for an Extensive Air Shower (EAS) to trigger an individual detector of a ground based array as a function of distance to the shower axis, taking into account energy, mass and direction of the primary cosmic ray. We apply this concept to the surface array of the Pierre Auger Observatory consisting of a 1.5 km spaced grid of about 1600 water Cherenkov stations. Using Monte Carlo simulations of ultra-high energy showers the LTP functions are derived for energies in the range between 10(17) and 10(19) eV and zenith angles up to 65 degrees. A parametrization combining a step function with an exponential is found to reproduce them very well in the considered range of energies and zenith angles. The LTP functions can also be obtained from data
Address [Abreu, P.; Andringa, S.; Assis, P.; Brogueira, P.; Cazon, L.; Conceicao, R.; Goncalves, P.; Pimenta, M.; Santo, C. E.; Santos, E.; Tome, B.] LIP, P-1000 Lisbon, Portugal, Email: auger_spokespersons@fnal.gov
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0927-6505 ISBN Medium
Area Expedition Conference
Notes WOS:000297434500006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 837
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Author Bouhova-Thacker, E.; Kostyukhin, V.; Koffas, T.; Liebig, W.; Limper, M.; Piacquadio, G.N.; Prokofiev, K.; Weiser, C.; Wildauer, A.
Title Expected Performance of Vertex Reconstruction in the ATLAS Experiment at the LHC Type Journal Article
Year (down) 2010 Publication IEEE Transactions on Nuclear Science Abbreviated Journal IEEE Trans. Nucl. Sci.
Volume 57 Issue 2 Pages 760-767
Keywords Data analysis; data reconstruction; high energy physics; pattern recognition; reconstruction algorithms; tracking; vertex detectors
Abstract In the harsh environment of the Large Hadron Collider at CERN (design luminosity of 10(34) cm(-2) s(-1)) efficient reconstruction of vertices is crucial for many physics analyses. Described in this paper is the expected performance of the vertex reconstruction used in the ATLAS experiment. The algorithms for the reconstruction of primary and secondary vertices as well as for finding photon conversions and vertex reconstruction in jets are described. The implementation of vertex algorithms which follows a very modular design based on object-oriented C++ is presented. A user-friendly concept allows event reconstruction and physics analyses to compare and optimize their choice among different vertex reconstruction strategies. The performance of implemented algorithms has been studied on a variety of Monte Carlo samples and results are presented.
Address [Bouhova-Thacker, Eva] Univ Lancaster, Lancaster LA1 4YB, England, Email: bouhova@mail.cern.ch
Corporate Author Thesis
Publisher Ieee-Inst Electrical Electronics Engineers Inc Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0018-9499 ISBN Medium
Area Expedition Conference
Notes ISI:000276679200006 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ pastor @ Serial 260
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Author Pierre Auger Collaboration (Abraham, J. et al); Pastor, S.
Title Trigger and aperture of the surface detector array of the Pierre Auger Observatory Type Journal Article
Year (down) 2010 Publication Nuclear Instruments & Methods in Physics Research A Abbreviated Journal Nucl. Instrum. Methods Phys. Res. A
Volume 613 Issue 1 Pages 29-39
Keywords Ultra high energy cosmic rays; Auger Observatory; Extensive air showers; Trigger; Exposure
Abstract The surface detector array of the Pierre Auger Observatory consists of 1600 water-Cherenkov detectors, for the study of extensive air showers (EAS) generated by ultra-high-energy cosmic rays. We describe the trigger hierarchy, from the identification of candidate showers at the level of a single detector, amongst a large background (mainly random single cosmic ray muons), up to the selection of real events and the rejection of random coincidences. Such trigger makes the surface detector array fully efficient for the detection of EAS with energy above 3 x 10(18) eV, for all zenith angles between 0 degrees and 60 degrees, independently of the position of the impact point and of the mass of the primary particle. In these range of energies and angles, the exposure of the surface array can be determined purely on the basis of the geometrical acceptance.
Address [Boncioli, D.; Delle Fratte, C.; Di Giulio, C.; Matthiae, G.; Petrinca, P.; Salina, G.; Verzi, V.] Univ Roma Tor Vergata, I-00173 Rome, Italy, Email: giorgio.matthiae@roma2.infn.it
Corporate Author Thesis
Publisher Elsevier Science Bv Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0168-9002 ISBN Medium
Area Expedition Conference
Notes ISI:000274772800005 Approved no
Is ISI yes International Collaboration yes
Call Number IFIC @ elepoucu @ Serial 499
Permanent link to this record