ArcAdiA

Expected Performance of the ATLAS Experiment: Detector, Trigger and Physics

2008-12-31T23:00:00Z

Expected Performance of the ATLAS Experiment: Detector, Trigger and Physics Aad, G.; Bacci, Cesare; Ceradini, Filippo; Di Luise, Silvestro; Diglio, Sara; Orestano, Domizia; Pastore, Fernanda; Petrucci, Fabrizio; Spogli, L.; et, al. 2009-01 The Large Hadron Collider (LHC) at CERN promises a major step forward in the understanding of the fundamental nature of matter. The ATLAS experiment is a general-purpose detector for the LHC, whose design was guided by the need to accommodate the wide spectrum of possible physics signatures. The major remit of the ATLAS experiment is the exploration of the TeV mass scale where ground breaking discoveries are expected. In the focus are the investigation of the electroweak symmetry breaking and linked to this the search for the Higgs boson as well as the search for Physics beyond the Standard Model. In this report a detailed examination of the expected performance of the ATLAS detector is provided, with a major aim being to investigate the experimental sensitivity to a wide range of measurements and potential observations of new physical processes. An earlier summary of the expected capabilities of ATLAS was compiled in 1999. Since that time, the design of the detector has been finalised, and construction and installation have been completed. An extensive test-beam programme was undertaken. Furthermore, the simulation and reconstruction software code and frameworks have been completely rewritten. Revisions incorporated reflect improved detector modelling as well as major technical changes to the software technology. Greatly improved understanding of calibration and alignment techniques, and their practical impact on performance, is now in place. The studies reported here are based on full simulations of the ATLAS detector response. A variety of event generators were employed. The simulation and reconstruction of these large event samples thus provided an important operational test of the new ATLAS software system. In addition, the processing was distributed world-wide over the ATLAS Grid facilities and hence provided an important test of the ATLAS computing system – this is the origin of the expression “CSC studies” (“computing system commissioning”), which is occasionally referred to in these volumes. This report is broadly divided into two parts: firstly the performance for identification of physics objects is examined in detail, followed by a detailed assessment of the performance of the trigger system. This part is subdivided into chapters surveying the capabilities for charged particle tracking, each of electron/photon, muon and tau identification, jet and missing transverse energy reconstruction, b-tagging algorithms and performance, and finally the trigger system performance. The second major subdivision of the report addresses physics measurement capabilities, and new physics search sensitivities. Individual chapters in this part discuss ATLAS physics capabilities in Standard Model QCD and electroweak processes, in the top quark sector, in b-physics, in searches for Higgs bosons, supersymmetry searches, and finally searches for other new particles predicted in more exotic models.

Forward production of charged pions with incident protons on nuclear targets at the CERN Proton Synchrotron

2009-09-29T22:00:00Z

Forward production of charged pions with incident protons on nuclear targets at the CERN Proton Synchrotron Apollonio, M.; Artamonov, A.; Bagulya, A.; Barr, G.; Blondel, A.; Bobisut, F.; Bogomilov, M.; Bonesini, M.; Booth, C.; Borghi, S.; Bunyatov, S.; Burguet-Castell, J.; Catanesi, M. G.; Cervera-Villanueva, A.; Chimenti, P.; Coney, L.; Di Capua, E.; Dore, U.; Dumarchez, J.; Edgecock, R.; Ellis, M.; Ferri, F.; Gastaldi, U.; Giani, S.; Giannini, G.; Gibin, D.; Gilardoni, S.; Gorbunov, P.; Goessling, C.; Gomez-Cadenas, J. J.; Grant, A.; Graulich, J. S.; Gregoire, G.; Grichine, V.; Grossheim, A.; Guglielmi, A.; Howlett, L.; Ivanchenko, A.; Ivanchenko, V.; Kayis-Topaksu, A.; Kirsanov, M.; Kolev, D.; Krasnoperov, A.; Martin-Albo, J.; Meurer, C.; Mezzetto, M.; Mills, G. B.; Morone, M. C.; Novella, P.; Orestano, Domizia; Palladino, V.; Panman, J.; Papadopoulos, I.; Pastore, Fernanda; Piperov, S.; Polukhina, N.; Popov, B.; Prior, G.; Radicioni, E.; Schmitz, D.; Schroeter, R.; Serdiouk, V.; Skoro, G.; Sorel, M.; Tcherniaev, E.; Temnikov, P.; Tereschenko, V.; Tonazzo, Alessandra; Tortora, Ludovico; Tsenov, R.; Tsukerman, I.; Vidal-Sitjes, G.; Wiebusch, C.; Zucchelli, P. 2009-09-30 Physical Review C 80 035208 Measurements of the double-differential pi(+/-) production cross section in the range of momentum 0.5 <= p <= 8.0 GeV/c and angle 0.025<= theta <= 0.25 rad in collisions of protons on beryllium, carbon, nitrogen, oxygen, aluminum, copper, tin, tantalum, and lead are presented. The data were taken with the large-acceptance HAdRon Production (HARP) detector in the T9 beamline of the CERN Proton Synchrotron. Incident particles were identified by an elaborate system of beam detectors. Thin targets of 5% of a nuclear interaction length were used. The tracking and identification of the produced particles were performed using the forward system of the HARP experiment. Results are obtained for the double-differential cross sections d(2)sigma s/dpd Omega mainly at four incident proton beam momenta (3, 5, 8, and 12GeV/c). Measurements are compared with the GEANT4 and MARS Monte Carlo generators. A global parametrization is provided as an approximation of all the collected datasets, which can serve as a tool for quick yield estimates.

Comparison of large-angle production of charged pions with incident protons on cylindrical long and short targets

2009-12-21T23:00:00Z

Comparison of large-angle production of charged pions with incident protons on cylindrical long and short targets Apollonio, M.; Artamonov, A.; Bagulya, A.; Barr, G.; Blondel, A.; Bobisut, F.; Bogomilov, M.; Bonesini, M.; Booth, C.; Borghi, S.; Bunyatov, S.; Burguet-Castell, J.; Catanesi, M. G.; Cervera-Villanueva, A.; Chimenti, P.; Coney, L.; Di Capua, E.; Dore, U.; Dumarchez, J.; Edgecock, R.; Ellis, M.; Ferri, F.; Gastaldi, U.; Giani, S.; Giannini, G.; Gibin, D.; Gilardoni, S.; Gorbunov, P.; Goessling, C.; Gomez-Cadenas, J. J.; Grant, A.; Graulich, J. S.; Gregoire, G.; Grichine, V.; Grossheim, A.; Guglielmi, A.; Howlett, L.; Ivanchenko, A.; Ivanchenko, V.; Kayis-Topaksu, A.; Kirsanov, M.; Kolev, D.; Krasnoperov, A.; Martin-Albo, J.; Meurer, C.; Mezzetto, M.; Mills, G. B.; Morone, M. C.; Novella, P.; Orestano, Domizia; Palladino, V.; Panman, J.; Papadopoulos, I.; Pastore, Fernanda; Piperov, S.; Polukhina, N.; Popov, B.; Prior, G.; Radicioni, E.; Schmitz, D.; Schroeter, R.; Skoro, G.; Sorel, M.; Tcherniaev, E.; Temnikov, P.; Tereschenko, V.; Tonazzo, Alessandra; Tortora, Ludovico; Tsenov, R.; Tsukerman, I.; Vidal-Sitjes, G.; Wiebusch, C.; Zucchelli, P. 2009-12-22 Physical Review C 80 065204 The HARP Collaboration has presented measurements of the double-differential pi(+/-) production cross section in the range of momentum 100 MeV/c <= p <= 800 MeV/c and angle 0.35 rad <=theta <= 2.15 rad with proton beams hitting thin nuclear targets. In many applications the extrapolation to long targets is necessary. In this article the analysis of data taken with long (one interaction length) solid cylindrical targets made of carbon, tantalum, and lead is presented. The data were taken with the large-acceptance HARP detector in the T9 beam line of the CERN proton synchrotron. The secondary pions were produced by beams of protons with momenta of 5, 8, and 12GeV/c. The tracking and identification of the produced particles were performed using a small-radius cylindrical time projection chamber placed inside a solenoidal magnet. Incident protons were identified by an elaborate system of beam detectors. Results are obtained for the double-differential yields per target nucleon d(2)sigma/dpd theta. The measurements are compared with predictions of the MARS and GEANT4 Monte Carlo simulations.

Large-angle production of charged pions with incident pion beams on nuclear targets

2009-12-28T23:00:00Z

Large-angle production of charged pions with incident pion beams on nuclear targets Apollonio, M.; Artamonov, A.; Bagulya, A.; Barr, G.; Blondel, A.; Bobisut, F.; Bogomilov, M.; Bonesini, M.; Booth, C.; Borghi, S.; Bunyatov, S.; Burguet-Castell, J.; Catanesi, M. G.; Cervera-Villanueva, A.; Chimenti, P.; Coney, L.; Di Capua, E.; Dore, U.; Dumarchez, J.; Edgecock, R.; Ellis, M.; Ferri, F.; Gastaldi, U.; Giani, S.; Giannini, G.; Gibin, D.; Gilardoni, S.; Gorbunov, P.; Goessling, C.; Gomez-Cadenas, J. J.; Grant, A.; Graulich, J. S.; Gregoire, G.; Grichine, V.; Grossheim, A.; Guglielmi, A.; Howlett, L.; Ivanchenko, A.; Ivanchenko, V.; Kayis-Topaksu, A.; Kirsanov, M.; Kolev, D.; Krasnoperov, A.; Martin-Albo, J.; Meurer, C.; Mezzetto, M.; Mills, G. B.; Morone, M. C.; Novella, P.; Orestano, Domizia; Palladino, V.; Panman, J.; Papadopoulos, I.; Pastore, Fernanda; Piperov, S.; Polukhina, N.; Popov, B.; Prior, G.; Radicioni, E.; Schmitz, D.; Schroeter, R.; Skoro, G.; Sorel, M.; Tcherniaev, E.; Temnikov, P.; Tereschenko, V.; Tonazzo, Alessandra; Tortora, Ludovico; Tsenov, R.; Tsukerman, I.; Vidal-Sitjes, G.; Wiebusch, C.; Zucchelli, P. 2009-12-29 Physical Review C 80 065207 Measurements of the double-differential pi(+/-) production cross section in the range of momentum 100 <= p <= 800 MeV/c and angle 0.35<=theta <= 2.15 rad using pi(+/-) beams incident on beryllium, aluminum, carbon, copper, tin, tantalum, and lead targets are presented. The data were taken with the large-acceptance hadron production (HARP) detector in the T9 beam line of the CERN Proton Synchrotron. The secondary pions were produced by beams in a momentum range from 3 to 12.9GeV/c hitting a solid target with a thickness of 5% of a nuclear interaction length. The tracking and identification of the produced particles was performed using a small-radius cylindrical time projection chamber placed inside a solenoidal magnet. Incident particles were identified by an elaborate system of beam detectors. Results are obtained for the double-differential cross sections d(2)sigma/dp d theta at six incident-beam momenta. Data at 3,5,8, and12GeV/c are available for all targets, while additional data at 8.9 and12.9GeV/c were taken in positive particle beams on Be and Al targets, respectively. The measurements are compared with several generators of GEANT4 and the MARS Monte Carlo simulation.

A study of quasi-elastic muon neutrino and antineutrino scattering in the NOMAD experiment

2009-09-30T22:00:00Z

A study of quasi-elastic muon neutrino and antineutrino scattering in the NOMAD experiment Lyubushkin, V.; Popov, B.; Kim, J. J.; Camilleri, L.; Levy, J. -M.; Mezzetto, M.; Naumov, D.; Alekhin, S.; Astier, P.; Autiero, D.; Baldisseri, A.; Baldo-Ceolin, M.; Banner, M.; Bassompierre, G.; Benslama, K.; Besson, N.; Bird, I.; Blumenfeld, B.; Bobisut, F.; Bouchez, J.; Boyd, S.; Bueno, A.; Bunyatov, S.; Cardini, A.; Cattaneo, P. W.; Cavasinni, V.; Cervera-Villanueva, A.; Challis, R.; Chukanov, A.; Collazuol, G.; Conforto, G.; Conta, C.; Contalbrigo, M.; Cousins, R.; Daniels, D.; Degaudenzi, H.; Del Prete, T.; De Santo, A.; Dignan, T.; Di Lella, L.; do Couto e Silva, E.; Dumarchez, J.; Ellis, M.; Feldman, G. J.; Ferrari, R.; Ferrere, D.; Flaminio, V.; Fraternali, M.; Gaillard, J. -M.; Gangler, E.; Geiser, A.; Geppert, D.; Gibin, D.; Gninenko, S.; Godley, A.; Gomez-Cadenas, J. -J.; Gosset, J.; Goessling, C.; Gouanere, M.; Grant, A.; Graziani, G.; Guglielmi, A.; Hagner, C.; Hernando, J.; Hubbard, D.; Hurst, P.; Hyett, N.; Iacopini, E.; Joseph, C.; Juget, F.; Kent, N.; Kirsanov, M.; Klimov, O.; Kokkonen, J.; Kovzelev, A.; Krasnoperov, A.; Kulagin, S.; Kustov, D.; Lacaprara, S.; Lachaud, C.; Lakic, B.; Lanza, A.; La Rotonda, L.; Laveder, M.; Letessier-Selvon, A.; Ling, J.; Linssen, L.; Ljubicic, A.; Long, J.; Lupi, A.; Marchionni, A.; Martelli, F.; Mechain, X.; Mendiburu, J. -P.; Meyer, J. -P.; Mishra, S. R.; Moorhead, G. F.; Nedelec, P.; Nefedov, Yu.; Nguyen-Mau, C.; Orestano, Domizia; Pastore, Fernanda; Peak, L. S.; Pennacchio, E.; Pessard, H.; Petti, R.; Placci, A.; Polesello, G.; Pollmann, D.; Polyarush, A.; Poulsen, C.; Rebuffi, L.; Rico, J.; Riemann, P.; Roda, C.; Rubbia, A.; Salvatore, F.; Samoylov, O.; Schahmaneche, K.; Schmidt, B.; Schmidt, T.; Sconza, A.; Seaton, M.; Sevior, M.; Sillou, D.; Soler, F. J. P.; Sozzi, G.; Steele, D.; Stiegler, U.; Stipcevic, M.; Stolarczyk, Th.; Tareb-Reyes, M.; Taylor, G. N.; Tereshchenko, V.; Toropin, A.; Touchard, A. -M.; Tovey, S. N.; Tran, M. -T.; Tsesmelis, E.; Ulrichs, J.; Vacavant, L.; Valdata-Nappi, M.; Valuev, V.; Vannucci, F.; Varvell, K. E.; Veltri, M.; Vercesi, V.; Vidal-Sitjes, G.; Vieira, J. -M.; Vinogradova, T.; Weber, F. V.; Weisse, T.; Wilson, F. F.; Winton, L. J.; Wu, Q.; Yabsley, B. D.; Zaccone, H.; Zuber, K.; Zuccon, P. 2009-10 European Physical Journal C 63 355-381 We have studied the muon neutrino and antineutrino quasi-elastic (QEL)scattering reactions (v(mu)n -> mu(-)p and (v) over bar mu p -> mu(+)n)using a set of experimental data collected by the NOMAD Collaboration.We have performed measurements of the cross-section of these processes on a nuclear target (mainly carbon) normalizing it to the total v(mu)((v) over bar mu) charged-current cross section. The results for the flux-averaged QEL cross sections in the (anti) neutrino energy interval3-100 GeV are v(mu) = (0.92 +/- 0.02(stat) +/- 0.06(syst))x 10(-38) cm(2) and (v) over bar (mu) = (0.81 +/-0.05(stat) +/- 0.09(syst)) x 10(-38) cm(2) for neutrino and antineutrino, respectively. The axial mass parameter M-A was extracted from the measured quasi-elastic neutrino cross section. The corresponding result is M-A = 1.05 +/- 0.02(stat)+/- 0.06(syst) GeV. Itis consistent with the axial mass values recalculated from the antineutrino cross section and extracted from the pure Q(2) shape analysis of the high purity sample of v(mu) quasi-elastic 2-trackevents, but has smaller systematic error and should be quoted as the main result of this work. Our measured MA is found to be in good agreement with the world average value obtained in previous deuterium filled bubble chamber experiments. The NOMAD measurement of MA is lower than those recently published by K2K and Mini-BooNE Collaborations.However, within the large errors quoted by these experiments on MA,these results are compatible with the more precise NOMAD value.

A measurement of coherent neutral pion production in neutrino neutral current interactions in the NOMAD experiment

2009-11-29T23:00:00Z

A measurement of coherent neutral pion production in neutrino neutral current interactions in the NOMAD experiment Kullenberg, C. T.; Mishra, S. R.; Seaton, M. B.; Kim, J. J.; Tian, X. C.; Scott, A. M.; Kirsanov, M.; Petti, R.; Alekhin, S.; Astier, P.; Autiero, D.; Baldisseri, A.; Baldo-Ceolin, M.; Banner, M.; Bassompierre, G.; Benslama, K.; Besson, N.; Bird, I.; Blumenfeld, B.; Bobisut, F.; Bouchez, J.; Boyd, S.; Bueno, A.; Bunyatov, S.; Camilleri, L.; Cardini, A.; Cattaneo, P. W.; Cavasinni, V.; Cervera-Villanueva, A.; Challis, R.; Chukanov, A.; Collazuol, G.; Conforto, G.; Conta, C.; Contalbrigo, M.; Cousins, R.; Degaudenzi, H.; De Santo, A.; Del Prete, T.; Di Lella, L.; do Couto e Silva, E.; Dumarchez, J.; Ellis, M.; Feldman, G. J.; Ferrari, R.; Ferrere, D.; Flaminio, V.; Fraternali, M.; Gaillard, J. -M.; Gangler, E.; Geiser, A.; Geppert, D.; Gibin, D.; Gninenko, S.; Godley, A.; Gomez-Cadenas, J. -J.; Gosset, J.; Goessling, C.; Gouanere, M.; Grant, A.; Graziani, G.; Guglielmi, A.; Hagner, C.; Hernando, J.; Hurst, P.; Hyett, N.; Iacopini, E.; Joseph, C.; Juget, F.; Kent, N.; Klimov, O.; Kokkonen, J.; Kovzelev, A.; Krasnoperov, A.; Kulagin, S.; Lacaprara, S.; Lachaud, C.; Lakic, B.; Lanza, A.; La Rotonda, L.; Laveder, M.; Letessier-Selvon, A.; Levy, J. -M.; Ling, J.; Linssen, L.; Ljubicic, A.; Long, J.; Lupi, A.; Lyubushkin, V.; Marchionni, A.; Martelli, F.; Mechain, X.; Mendiburu, J. -P; Meyer, J. -P.; Mezzetto, M.; Moorhead, G. F.; Naumov, D.; Nedelec, P.; Nefedov, Yu.; Nguyen-Mau, C.; Orestano, Domizia; Pastore, Fernanda; Peak, L. S.; Pennacchio, E.; Pessard, H.; Placci, A.; Polesello, G.; Pollmann, D.; Polyarush, A.; Poulsen, C.; Popov, B.; Rebuffi, L.; Rico, J.; Riemann, P.; Roda, C.; Rubbia, A.; Salvatore, F.; Samoylov, O.; Schahmaneche, K.; Schmidt, B.; Schmidt, T.; Sconza, A.; Sevior, M.; Sillou, D.; Soler, F. J. P.; Sozzi, G.; Steele, D.; Stiegler, U.; Stipcevic, M.; Stolarczyk, Th.; Tareb-Reyes, M.; Taylor, G. N.; Tereshchenko, V.; Toropin, A.; Touchard, A. -M.; Tovey, S. N.; Tran, M. -T.; Tsesmelis, E.; Ulrichs, J.; Vacavant, L.; Valdata-Nappi, M.; Valuev, V.; Vannucci, F.; Varvell, K. E.; Veltri, M.; Vercesi, V.; Vidal-Sitjes, G.; Vieira, J. M.; Vinogradova, T.; Weber, F. V.; Weisse, T.; Wilson, F. F.; Winton, L. J.; Wu, Q.; Yabsley, B. D.; Zaccone, H.; Zuber, K.; Zuccon, P. 2009-11-30 Physics Letters B 682 177-184 We present a Study of exclusive neutral pion production in neutrino-nucleus Neutral Current interactions using data from the NOMAD experiment at the CERN SPS. The data correspond to 1.44 x 10(6) muon-neutrino Charged Current interactions in the energy range 2.5 <=E-nu <= 300 GeV. Neutrino events with only one visible pi(0) in the final state are expected to result from two Neutral Current processes:coherent pi(0) production, nu + A -> nu + A + pi(0) and single pi(0)production in neutrino-nucleon scattering. The signature of coherent pi(0) production is an emergent pi(0) almost collinear with the incident neutrino while pi(0)'s produced in neutrino-nucleon deep inelastic scattering have larger transverse momenta. In this analysis all relevant backgrounds to the coherent pi(0) production signal are measured using data themselves. Having determined the backgrounds, and using the Rein-Sehgal model for the coherent pi(0) production to compute the detection efficiency, we obtain 4630 +/- 522(stat) +/-426(syst) corrected coherent-pi(0) events with E-pi 0 >= 0.5 GeV. We measure sigma(nu A -> nu A pi(0)) = 172.6 +/- 8.1 (stat) +/- 6.9(syst)]x 10(-40) cm(2)/nucleus. This is the most precise measurement of the coherent pi(0) production to date. (C) 2009 Elsevier B.V. All rights reserved.