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 00:00:00 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), Vol. 39:5
• Country of Publication: United States
• Language: English

Related Subjects

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