The Lateral Trigger Probability function for the Ultra-High Energy Cosmic Ray showers detected by the Pierre Auger Observatory

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 using events simultaneously observed by the fluorescence and the surface detector of the Pierre Auger Observatory (hybrid events). We validate the Monte Carlo results showing how LTP functions from data are in good agreement with simulations.

Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory

The Pierre Auger Collaboration has reported. evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies E > E-th = 5.5 x 10(19) eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at E > E-th are heavy nuclei with charge Z, the proton component of the sources should lead to excesses in the same regions at energies E/Z. We here report the lack of anisotropies in these directions at energies above E-th/Z (for illustrative values of Z = 6, 13, 26). If the anisotropies above E-th are due to nuclei with charge Z, and under reasonable assumptions about the acceleration process, these observations imply stringent constraints on the allowed proton fraction at the lower energies.

High energy nuclear reactions : a literature search /

The literature has been searched for references pertaining to high energy reactions of interest to nuclear chemists. Nuclear Science Abstracts was the main source of references and wherever possible the complete abstract was retained.

Attenuation and high energy neutron production measurements for 190 mev deuterons and 340 mev protons /

"Issued August 29, 1951"

Products of high-energy deuteron and helium ion bombardments of copper /

Work performed at the University of California.

MURA summer study reports on design and utilization of high-energy accelerators.

Abstracts in English.

Visit of U.S. high-energy physics team to USSR, May 1960 /

Cover title.

ROSAT : an international mission exploring the high energy universe.

Mode of access: Internet.

Theoretical Methods in the Dosimetry of High-Energy Particles [electronic resource]

Mode of access: Internet.

Sampling macroinvertebrates on high-energy sand beaches /

Includes glossary.

An investigation of high energy radio propagation in the atmosphere

"RADC-TDR-63-410."

Effect of nuclear radiation on organic materials, specifically magnet insulations in high-energy accelerators /

"March 1965."

High energy accelerator design.

"References": p. 62-63.

Proceedings of the 6th High Energy Heavy Ion Study and 2nd Workshop on Anomalons, Lawrence Berkeley Laboratory, University of California, June 28-July 1, 1983 /

"DE84005862"--Label mounted on cover.

4th High Energy Heavy Ion Summer Study : July 24-28, 1978, Lawrence Berkeley Laboratory, University of California, Berkeley.

"CONF-780766."