Inelasticity Distribution Of Hadron-pb Collisions In The Energy Region Exceeding 1014 Ev From Mountain Cosmic Ray Experiments

The inelasticity distribution of hadron-lead collisions in the energy region exceeding 1014 eV is estimated on the basis of 66 events, induced by cosmic ray hadrons and detected at high mountain altitudes at Pamir (4300 m, 595 g/cm2). The distribution of the best fitting is approximated as g(K)dK=[α(1-K)m1-1 + βKm2-1]dK, where m1=0.5, m2=1.125, α=0.26, β=0.55, giving 〈K〉=0.60. The errors of the parameters are discussed in the text. The distribution is compared with those which are based on theoretical models. ©1999 The American Physical Society.611110Frichter, G.M., Gaisser, T.K., Stanev, T., (1997) Phys. Rev. D, 56, p. 3135Fowler, G.N., Weiner, R.M., Wilk, G., (1985) Phys. Rev. Lett., 55, p. 173Fowler, G.N., Vourdas, A., Weiner, R.M., Wilk, G., (1987) Phys. Rev. D, 35, p. 870Fowler, G.N., Navarra, F.S., Plümer, M., Voudras, A., Weiner, R.M., Wilk, G., (1989) Phys. Rev. C, 40, p. 1219Shabelski, Yu.M., Weiner, R.M., Wilk, G., Włodarczyk, Z., (1992) J. Phys. G, 18, p. 1281Włodarczyk, Z., (1995) J. Phys. G, 21, p. 281Chou, T.T., Yang, C.N., (1985) Phys. Rev. D, 32, p. 1692Gaisser, T.K., Stanev, T., (1989) Phys. Lett. B, 219, p. 375Kaǐdalov, A.B., Ter-Martirosyan, K.A., (1987) Proceedings of the 20th International Cosmic Ray Conference, 5, p. 139(1984) Sov. J. Nucl. Phys., 40, p. 135Nazareth, R.A.M.S., Kodama, T., Portes Jr., D.A., (1992) Phys. Rev. D, 46, p. 2896Schatz, G., Thouw, T., Werner, K., Oehlschläger, J., Bekk, K., (1994) J. Phys. G, 20, p. 1267Gaisser, T.K., Protheroe, R.J., Turver, K.E., McComb, T.J.L., (1978) Rev. Mod. Phys., 50, p. 859Van Hove, L., Pokorski, S., (1975) Nucl. Phys., B86, p. 243Akashi, M., (1964) Prog. Theor. Phys. Suppl., 32, p. 1Feynman, R., (1969) Phys. Rev. Lett., 23, p. 1415Taylor, F.E., Carey, D.C., Johnson, J.R., Kammerud, R., Ritchie, D.J., Roberts, A., Sauer, J.R., Walker, J.K., (1976) Phys. Rev. D, 14, p. 1217Ohsawa, A., (1994) Prog. Theor. Phys., 92, p. 1005Arata, N., (1983) Nucl. Phys., B211, p. 189Tabuki, T., (1983) Prog. Theor. Phys. Suppl., 76, p. 40Chinellato, J.A., (1983) Prog. Theor. Phys. Suppl., 76, p. 1Alner, G.L., (1987) Phys. Rep., 5-6, p. 247Nishimura, J., (1967) Handbuch der Physik, 46 (2), p. 1. , Springer, BerlinArisawa, T., Fujimoto, Y., Hasegawa, S., Honda, K., Ito, H., Kopenkin, V.V., Semba, H., Strogova, O.P., (1994) Nucl. Phys., B424, p. 241Baradzei, L.T., (1992) Nucl. Phys. B, B370, p. 365Kopenkin, V., Fujimoto, Y., (1996) Nuovo Cimento C, 19, p. 1017Moriya, M., (1997), Master thesis, Waseda UniversityBarroso, S.L.C., Fujimoto, Y., Kopenkin, V., Moriya, M., Navia, C., Ohsawa, A., Shibuya, E.H., Tamada, M., (1997) Nucl. Phys. B (Proc. Suppl.), 52 B, p. 201(1997) Proceedings of the 25th International Cosmic Ray Conference, 6, p. 41Hama, Y., Paiva, S., (1997) Phys. Rev. Lett., 78, p. 3070Tamada, M., (1995) J. Phys. G, 21, p. 1387Knapp, J., Heck, D., Schatz, G., (1996) Report of Institut für Kernphysik, Forschungszentrum Karlsruhe, , Wissenchafteliche Berichte FZKA 5828Harr, R., Liapis, C., Karchin, P., Biino, C., Erhan, S., Hofmann, W., Kreuzer, P., Zweizig, J., (1997) Phys. Lett. B, 401, p. 176Tamada, M., Kopenkin, V.V., (1997) Nucl. Phys., B494, p. 3Ohsawa, A., (1971) Prog. Theor. Phys. Suppl., 47, p. 180Gaisser, T.K., (1990) Cosmic Rays and Particle Physics, , Cambridge University Press, Cambridge, Englan

The Offline Software Framework of the Pierre Auger Observatory

To be published in the ProceedingsInternational audienceThe Pierre Auger Observatory is designed to unveil the nature and the origins of the highest energy cosmic rays. The large and geographically dispersed collaboration of physicists and the wide-ranging collection of simulation and reconstruction tasks pose some special challenges for the offline analysis software. We have designed and implemented a general purpose framework which allows collaborators to contribute algorithms and sequencing instructions to build up the variety of applications they require. The framework includes machinery to manage these user codes, to organize the abundance of user-contributed configuration files, to facilitate multi-format file handling, and to provide access to event and time-dependent detector information which can reside in various data sources. A number of utilities are also provided, including a novel geometry package which allows manipulation of abstract geometrical objects independent of coordinate system choice. The framework is implemented in C++, and takes advantage of object oriented design and common open source tools, while keeping the user side simple enough for C++ novices to learn in a reasonable time. The distribution system incorporates unit and acceptance testing in order to support rapid development of both the core framework and contributed user code

The Pierre Auger Observatory offline software

The Pierre Auger Observatory aims to discover the nature and origins of the highest energy cosmic rays. The large number of physicists involved in the project and the diversity of simulation and reconstruction tasks pose a challenge for the offline analysis software, not unlike the challenges confronting software for very large high energy physics experiments. Previously we have reported on the design and implementation of a general purpose but relatively lightweight framework which allows collaborators to contribute algorithms and sequencing instructions to build up the variety of applications they require. In this report, we update the status of this work and describe some of the successes and difficulties encountered over the last few years of use. We explain the machinery used to manage user contributions, to organize the abundance of configuration files, to facilitate multi-format file handling, and to provide access to event and time-dependent detector information residing in various data sources. We also describe the testing procedures used to help maintain stability of the code in the face of a large number of contributions. Foundation classes will also be discussed, including a novel geometry package which allows manipulation of abstract geometrical objects independent of coordinate system choice

The Pierre Auger Observatory Offline Software

The Pierre Auger Observatory aims to discover the nature and origins of the highest energy cosmic rays. The large number of physicists involved in the project and the diversity of simulation and reconstruction tasks pose a challenge for the offline analysis software, not unlike the challenges confronting software for very large high energy physics experiments. Previously we have reported on the design and implementation of a general purpose but relatively lightweight framework which allows collaborators to contribute algorithms and sequencing instructions to build up the variety of applications they require. In this report, we update the status of this work and describe some of the successes and difficulties encountered over the last few years of use. We explain the machinery used to manage user contributions, to organize the abundance of configuration files, to facilitate multi-format file handling, and to provide access to event and time-dependent detector information residing in various data sources. We also describe the testing procedures used to help maintain stability of the code in the face of a large number of contributions. Foundation classes will also be discussed, including a novel geometry package which allows manipulation of abstract geometrical objects independent of coordinate system choice. © 2008 IOP Publishing Ltd.1193Abraham J et al. [Pierre Auger Collaboration] 2004 Nucl. Instrum. Meth. A 523, 50Ghia, P., Pierre Auger Collaboration (2007) Proc. 30th Intl. Cosmic Ray Conference (ICRC 2007), Merida, Mexico, 3-10 July 2007 Preprint, , arXiv:0706.1212 [astro-phKlages, H., HEAT : Enhancement Telescopes for the Pierre Auger Southern Observatory in Argentina Pierre Auger CollaborationMedina, M., Berisso, M., Allekotte, I., Etchegoyen, A., Tanco, G., Supanitsky, A., (2006) Nucl. Instrum. Meth. A, 566, p. 302AMIGA: A muon detector and infilled array for the Auger Observatory (2007) Proc. 30th Intl. Cosmic Ray Conference (ICRC 2007), Merida, , Etchegoyen A [Pierre Auger Collaboration, Mexico, 3-10 JulyArgirò, S., The offline software framework of the Pierre Auger Observatory (2005), Pierre Auger CollaborationArgiro S et al. 2007 Nucl. Instr. and Meth. A, doi:10.1016/j.nima.2007.07.010 Preprint arXiv:0707.1652 [astro-ph]http://www.w3.org/XMLhttp://tools.ietf.org/html/rfc3986http://www.w3.org/TR/xpathhttp:subversion.tigris.orghttp://www.gnu.org/software/autoconfhttp://www.gnu.org/software/ automakehttp://www.gnu.org/software/libtoolhttp://www.w3.org/XML/SchemaRivest, R., http://www.faqs.org/rfcsPatton, S., Concrete uses of XML in software development and data analysis (2003) Proc. Intl. Conf. on Computing in High-Energy Physics and Nuclear Physics (CHEP 2003), , See for example, La Jolla, California, USA 24-28 MarchSciutto, S., Preprint arXiv:astro-ph/9911331Heck, D., Knapp, J., Capdevielle, J., Schatz, G., Thuow, T., (1998) Report FZKA, , 6019Bergmann, T., (2007) Astropart. Phys, 26, p. 420Drescher, H., Farrar, G., Bleicher, M., Reiter, M., Soff, S., Stoecker, H., (2003) Phys.Rev, D67, p. 116001http://root.cern.chhttp://dev.mysql.comhttp://xml.apache.orgJosuttis, N., (1999) The C++ Standard Library, , see for example, Addison-Wesley, ISBN 0-201-37926-0http://www.w3.org/TR/REC-xmlhttp://cppunit.sourceforge.net/doc/1.8.0http://buildbot.sourceforge.nethttp://www.boost.orghttp://proj-clhep.web.cern.ch/proj-clhephttp://geant4.cern.ch/Agostinelli S et al. 2003 Nucl. Instrum. Meth. A 506, 250http://www.python.orgChudoba, J., Simulations and Offline Data Processing for the Auger Experiment Presented at EGEE User Forum, , http://indico.cern.ch/conferenceDisplay.py?confId=7247, Manchester, UK, 9-11 May 200

Anisotropy studies around the galactic centre at EeV energies with the Auger Observatory

Data from the Pierre Auger Observatory are analyzed to search for anisotropies near the direction of the Galactic Centre at EeV energies. The exposure of the surface array in this part of the sky is already significantly larger than that of the fore-runner experiments. Our results do not support previous findings of localized excesses in the AGASA and SUGAR data. We set an upper bound on a point-like flux of cosmic rays arriving from the Galactic Centre which excludes several scenarios predicting sources of EeV neutrons from Sagittarius $A$. Also the events detected simultaneously by the surface and fluorescence detectors (the `hybrid' data set), which have better pointing accuracy but are less numerous than those of the surface array alone, do not show any significant localized excess from this direction.Comment: Matches published versio

Atmospheric effects on extensive air showers observed with the Surface Detector of the Pierre Auger Observatory

Atmospheric parameters, such as pressure (P), temperature (T) and density, affect the development of extensive air showers initiated by energetic cosmic rays. We have studied the impact of atmospheric variations on extensive air showers by means of the surface detector of the Pierre Auger Observatory. The rate of events shows a ~10% seasonal modulation and ~2% diurnal one. We find that the observed behaviour is explained by a model including the effects associated with the variations of pressure and density. The former affects the longitudinal development of air showers while the latter influences the Moliere radius and hence the lateral distribution of the shower particles. The model is validated with full simulations of extensive air showers using atmospheric profiles measured at the site of the Pierre Auger Observatory.Comment: 24 pages, 9 figures, accepted for publication in Astroparticle Physic

Update on the correlation of the highest energy cosmic rays with nearby extragalactic matter

Data collected by the Pierre Auger Observatory through 31 August 2007 showed evidence for anisotropy in the arrival directions of cosmic rays above the Greisen-Zatsepin-Kuz'min energy threshold, \nobreak{$6\times 10^{19}$eV}. The anisotropy was measured by the fraction of arrival directions that are less than $3.1^\circ$ from the position of an active galactic nucleus within 75 Mpc (using the V\'eron-Cetty and V\'eron $12^{\rm th}$ catalog). An updated measurement of this fraction is reported here using the arrival directions of cosmic rays recorded above the same energy threshold through 31 December 2009. The number of arrival directions has increased from 27 to 69, allowing a more precise measurement. The correlating fraction is $(38^{+7}_{-6})$, compared with $21$ expected for isotropic cosmic rays. This is down from the early estimate of $(69^{+11}_{-13})$. The enlarged set of arrival directions is examined also in relation to other populations of nearby extragalactic objects: galaxies in the 2 Microns All Sky Survey and active galactic nuclei detected in hard X-rays by the Swift Burst Alert Telescope. A celestial region around the position of the radiogalaxy Cen A has the largest excess of arrival directions relative to isotropic expectations. The 2-point autocorrelation function is shown for the enlarged set of arrival directions and compared to the isotropic expectation.Comment: Accepted for publication in Astroparticle Physics on 31 August 201

The exposure of the hybrid detector of the Pierre Auger Observatory

The Pierre Auger Observatory is a detector for ultra-high energy cosmic rays. It consists of a surface array to measure secondary particles at ground level and a fluorescence detector to measure the development of air showers in the atmosphere above the array. The "hybrid" detection mode combines the information from the two subsystems. We describe the determination of the hybrid exposure for events observed by the fluorescence telescopes in coincidence with at least one water-Cherenkov detector of the surface array. A detailed knowledge of the time dependence of the detection operations is crucial for an accurate evaluation of the exposure. We discuss the relevance of monitoring data collected during operations, such as the status of the fluorescence detector, background light and atmospheric conditions, that are used in both simulation and reconstruction.Comment: Paper accepted by Astroparticle Physic

The Fluorescence Detector of the Pierre Auger Observatory

The Pierre Auger Observatory is a hybrid detector for ultra-high energy cosmic rays. It combines a surface array to measure secondary particles at ground level together with a fluorescence detector to measure the development of air showers in the atmosphere above the array. The fluorescence detector comprises 24 large telescopes specialized for measuring the nitrogen fluorescence caused by charged particles of cosmic ray air showers. In this paper we describe the components of the fluorescence detector including its optical system, the design of the camera, the electronics, and the systems for relative and absolute calibration. We also discuss the operation and the monitoring of the detector. Finally, we evaluate the detector performance and precision of shower reconstructions.Comment: 53 pages. Submitted to Nuclear Instruments and Methods in Physics Research Section

Advanced functionality for radio analysis in the Offline software framework of the Pierre Auger Observatory

The advent of the Auger Engineering Radio Array (AERA) necessitates the development of a powerful framework for the analysis of radio measurements of cosmic ray air showers. As AERA performs "radio-hybrid" measurements of air shower radio emission in coincidence with the surface particle detectors and fluorescence telescopes of the Pierre Auger Observatory, the radio analysis functionality had to be incorporated in the existing hybrid analysis solutions for fluoresence and surface detector data. This goal has been achieved in a natural way by extending the existing Auger Offline software framework with radio functionality. In this article, we lay out the design, highlights and features of the radio extension implemented in the Auger Offline framework. Its functionality has achieved a high degree of sophistication and offers advanced features such as vectorial reconstruction of the electric field, advanced signal processing algorithms, a transparent and efficient handling of FFTs, a very detailed simulation of detector effects, and the read-in of multiple data formats including data from various radio simulation codes. The source code of this radio functionality can be made available to interested parties on request.Comment: accepted for publication in NIM A, 13 pages, minor corrections to author list and references in v