Abundance of primary protons at (1--3) x 10/sup 15/ eV inferred from a simulation of extensive air showers with. gamma. -ray families

Journal Article · Wed Mar 01 04:00:00 EST 1989 · Phys. Rev. D; (United States)

DOI:https://doi.org/10.1103/PhysRevD.39.1275· OSTI ID:6535577

Shima, M; Saito, T; Sakata, M; Yamamoto, Y; Kasahara, K; Yuda, T; Torii, S; Hotta, N

A Monte Carlo simulation of extensive air showers (EAS's) was done under a particle-interaction model and was compared with the EAS's accompanied by ..gamma..-ray and hadronic families with total energy summationE/sub ..gamma..//sub ,//sub H/ greater than 10 TeV obtained in the Mt. Norikura experiment (2780 m above sea level). The strong correlation between the shower size N/sub e/ of EAS's with family and the primary energy, E/sub 0/, was obtained from the simulation as E/sub 0//N/sub e/ = (2.0/sub -0.7//sup +2.7/) GeV with 95% width. The flux of the EAS's with family is sensitive to the chemical composition, especially to the fraction of protons in the primary cosmic-ray particles. The fraction of protons is inferred to be (20 +- 6)% and (23 +- 9)%, with one standard deviation (1sigma), at energy (1.4/sub -0.5//sup +1.9/) x 10/sup 15/ eV and (2.8/sub -1.0//sup +3.8/) x 10/sup 15/ eV with 95% confidence interval, respectively, under the assumption of increasing cross section sigma/sub p//sub -air/proportionalE/sup 0.055/ and approximate Feynman scaling in the fragmentation region. These values are in agreement with the values obtained from other mountain emulsion-chamber experiments within 2sigma. The proton fraction thus obtained, around 20%, is much less than the normal abundance (approx.40%) expected from direct observations at lower energies around 10/sup 12/ eV.

• Research Organization: Department of Physics, Konan University, Kobe, Japan
• OSTI ID: 6535577
• Journal Information: Phys. Rev. D; (United States), Journal Name: Phys. Rev. D; (United States) Vol. 39:5; ISSN PRVDA
• Country of Publication: United States
• Language: English

Related Subjects

640101* -- Astrophysics & Cosmology-- Cosmic Radiation
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
BARYON-BARYON INTERACTIONS
BARYONS
COSMIC PHOTONS
COSMIC PROTONS
COSMIC RADIATION
COSMIC SHOWERS
CROSS SECTIONS
ELEMENTARY PARTICLES
ENERGY DEPENDENCE
ENERGY RANGE
EXTENSIVE AIR SHOWERS
FERMIONS
HADRON-HADRON INTERACTIONS
HADRONS
INELASTIC SCATTERING
INTERACTIONS
IONIZING RADIATIONS
MASSLESS PARTICLES
MONTE CARLO METHOD
NUCLEAR EMULSIONS
NUCLEON-ANTINUCLEON INTERACTIONS
NUCLEON-NUCLEON INTERACTIONS
NUCLEONS
PARTICLE INTERACTIONS
PHOTONS
PRIMARY COSMIC RADIATION
PROTON-ANTIPROTON INTERACTIONS
PROTON-NUCLEON INTERACTIONS
PROTON-PROTON INTERACTIONS
PROTONS
RADIATIONS
SCATTERING
SECONDARY COSMIC RADIATION
SHOWERS
SIMULATION
TEV RANGE