Search for disoriented chiral condensate in cosmic gamma-hadron families

We present a systematic study of the large asymmetries in neutral pion fraction distribution in high energy cosmic ray families (100 TeV<E-vis<700 TeV) detected at high mountain altitudes at Pamir (4300 m, 595 g/cm(2)). With this in mind we have constructed robust observables, ratios of factorial moments, in experimental and simulated families in a similar way. We have found that our experimental data do not exclude the possibility of a DCC formation mechanism in high energy interactions. [S0556-2821(99)06901-5].59

GAMMA-RAY BUNDLES AT THE CORES OF EXTENSIVE AIR SHOWERS AND PRIMARY COSMIC-RAY IDENTIFICATION

We present a useful clue to estimate the energy and chemical composition of the primary cosmic radiation between 10(14) and 10(17) eV. The method uses various kinds of quantities as measure by a hybrid detector, an emulsion chamber in the central part of an extensive air shower (EAS) array at mountain altitude. The characteristic features needed for the analysis are derived in detail through the Monte Carlo method. The procedure permits an analysis on individual events; it gives an estimation of the mass and energy of a primary nucleus initiating a shower. The estimation of the primary energy is with quite negligible ambiguity. We show that the EAS size measurement could be complementary to quantities as measured by an emulsion chamber detector to improve the accuracy of the primary cosmic ray identification.5294976498

The offline software framework of the Pierre auger observatory

The 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. (C) 2007 Elsevier B.V. All rights reserved.58031485149