Mini-clusters

Experimental results of mini-clusters observed in Chacaltaya emulsion chamber no.19 are summarized. The study was made on 54 single core shower upper and 91 shower clusters of E(gamma) 10 TeV from 30 families which are visible energy greater than 80 TeV and penetrate through both upper and lower detectors of the two-story chamber. The association of hadrons in mini-cluster is made clear from their penetrative nature and microscopic observation of shower continuation in lower chamber. Small P sub t (gamma) of hadrons in mini-clusters remained in puzzle

On The Question Of The Energy Dependence Of Inelasticity

We discuss the question of the energy dependence of inelasticity in very-high-energy hadronic interactions. From existing extensive-air-shower data, a definite conclusion cannot yet be reached. However, Glauber model realistic calculations and recent results from Tevatron suggest a slow increase of the mean inelasticity with energy. © 1992.2791-2149152Amos, (1990) Phys. Lett. B, 243, p. 158Bellandi, Mundim, Dias de Deus, Covolan, J. Phys. C (1991) J. Phys. C, , to be publishedBurnett, (1990) Astrophys. J., 349, p. L25Allkofer, (1975) Introduction to cosmic radiation, , Verlag Karl Thiemig, MunichLiland, (1987) Proc. XXth Intern. Cosmic ray Conf., 6, p. 178. , IUPAP, (Moscow, USSR)Glauber, Mathiae, (1970) Nucl. Phys. B, 21, p. 135Hofstadter, Nuclear and Nucleon Scattering of High-Energy Electrons (1957) Annual Review of Nuclear Science, 7, p. 231Linsley, (1985) Proc. XIXth Intern. Cosmic ray Conf., 6, p. 1. , La Jolla, USA, and references therein for experimental dataHara, (1983) Phys. Rev. Lett., 50, p. 2058Hara, (1983) Proc. XVIIth Intern. Cosmic ray Conf., 11, p. 354. , Bangalore, IndiaBaltrusaitis, (1984) Phys. Rev. Lett., 52, p. 1380Bellandi, On the behaviour of inelasticity at very high energy (1991) Physics Letters B, 262, p. 102Brooke, Wolfendale, (1964) Proc. Phys. Soc., 83, p. 843Ashton, (1970) Acta Phys. Acad. Sci. Hung., 29, p. 25Vall, (1987) Sov. J. Nucl. Phys., 44, p. 806Wilk, (1991) Contrib. XXIInd Intern. Cosmic ray Conf., , Dublin, IrelandFowler, (1987) Phys. Rev. D, 35, p. 870Gaisser, (1989) Phys. Lett. B, 219, p. 375Gaisser, (1990) Proc. 21st Intern. Cosmic ray Conf., 8, p. 55. , AdelaideKopeliovich, (1989) Phys. Rev. D, 39, p. 769Azaryan, (1975) Sov. J. Nucl. Phys., 20, p. 213Slavatinskii, (1964) Sov. Phys. JETP, 19, p. 1452Basile, (1983) Nuovo Cimento, 73 A, p. 32

The charmonium and bottomonium mass spectroscopy with a simple approximaton of the kinetic term

In this paper we propose a particular description of meson spectroscopy, with emphasis in heavy bound states like charmonia and bottomonia, after working on the main aspects of the construction of an effective potential model. We use the prerogatives from ``soft QCD'' to determine the effective potential terms, establishing the asymptotic Coulomb term from one gluon exchange approximation. At the same time, a linear confinement term is introduced in agreement with QCD and phenomenological prescription. The main aspect of this work is the simplification in the calculation, consequence of a precise and simplified description of the kinetic term of the Hamiltonian. With this proposition we perform the calculations of mass spectroscopy for charmonium and bottomonium mesons and we discuss the real physical possibilities of developing a generalized potential model, its possible advantages relative to experimental parameterization and complexity in numerical calculations

Determination of the calorimetric energy in extensive air showers

The contribution of different components of an air shower to the total energy deposit in the atmosphere, for different angles and primary particles, was studied using the CORSIKA air shower simulation code. The amount of missing energy, parameterized in terms of the calorimetric energy, was calculated. The results show that this parameterization varies less than 1% with angle or observation level. The dependence with the primary mass is less than 5% and, with the high energy hadronic interaction model, less than 2%. The systematic error introduced by the use of just one parameterization of the missing energy correction function, for an equal mixture of proton and iron at 45deg, was calculated to be below 3%. We estimate the statistical error due to shower-to-shower fluctuations to be about 1%.Comment: 15 pages, 4 figures, 4 tables. This version corresponds to the one aproved for publication in Astroparticle Physic

MARTA: A high-energy cosmic-ray detector concept with high-accuracy muon measurement

A new concept for the direct measurement of muons in air showers is presented. The concept is based on resistive plate chambers (RPCs), which can directly measure muons with very good space and time resolution. The muon detector is shielded by placing it under another detector able to absorb and measure the electromagnetic component of the showers such as a water-Cherenkov detector, commonly used in air shower arrays. The combination of the two detectors in a single, compact detector unit provides a unique measurement that opens rich possibilities in the study of air showers.Comment: 11 page

Outdoor Systems Performace and Upgrade

Over the last two decades, the possibility of using RPCs in outdoors systems has increased considerably. Our group has participated in this effort having installed several systems and continues to work on their optimization, while simultaneously studying and developing new approaches that can to use of RPCs in outdoor applications. In particular, some detectors were deployed in the field at the Pierre Auger Observatory in 2019 remained inactive, awaiting the commissioning of support systems. During the pandemic the detectors were left without gas flow for more than two years, but were recently reactivated with no major problems. The LouMu project combines particle physics and geophysics in order to map large geologic structures, using Muon Tomography. The development of the RPC system used and the data from the last two years will be presented. Finally, recent advances in a large area (1 m2) double gap-sealed RPC will be presented

Operations of and Future Plans for the Pierre Auger Observatory

Technical reports on operations and features of the Pierre Auger Observatory, including ongoing and planned enhancements and the status of the future northern hemisphere portion of the Observatory. Contributions to the 31st International Cosmic Ray Conference, Lodz, Poland, July 2009.Comment: Contributions to the 31st ICRC, Lodz, Poland, July 200