The vertical sea-level muon spectrum at energies above 1 GeV and the muon intensities at depths up to 18 km w.e. in different rocks and in water are calculated. The results are particularly collated with a great body of the ground-level, underground, and underwater muon data. In the hadron-cascade calculations, we take into account the logarithmic growth with energy of inelastic cross sections and pion, kaon, and nucleon generation in pion-nucleus collisions. For evaluating the prompt-muon contribution to the muon flux, we apply the two phenomenological approaches to the charm production problem: the recombination quark-parton model and the quark-gluon string model. To solve the muon transport equation at large depths of a homogeneous medium, we used a semianalytical method, which allows the inclusion of an arbitrary ~decreasing! muon spectrum at the medium boundary and real energy dependence of both continuous and discrete muon energy losses. The method is checked for accuracy by direct Monte Carlo calculation. Whenever possible, we give simple fitting formulas describing our numerical results. @S0556-2821~98!00313-0# PACS number~s!: 13.85.Tp, 96.40.Tv

Atmospheric muon flux at sea level, underground and underwater

Cosmogenic Chlorine-36 Production in Calcite by Muons

Atmospheric neutrino–fluxes are calculated over the wide energy range from 30 MeV to 3,000 GeV for the study of neutrino–physics using the data from underground neutrino–detectors. In this calculation, a full Monte Carlo method is employed for low energy neutrinos (30 MeV – 3 GeV), while a hybrid method is used for high energy neutrinos (1 – 3,000 GeV). At low energies, the ratio (�e+¯�e)/(�µ+¯�µ) agrees well with other calculations and is significantly different from observations. For the high energy neutrino–fluxes, the zenith angle dependence of atmospheric neutrino–flux is studied in detail, so that neutrino–oscillation parameters can be calculated for comparison with experimental results. The atmospheric muon–flux at high altitude and at sea level is studied to calibrate the neutrino–fluxes at low energies and high energies respectively. The agreement of our calculation with observations is satisfactory. The uncertainty of atmospheric neutrino–fluxes is also studied.

Calculation of the flux of atmospheric neutrinos

http://www-rccn.icrr.u-tokyo.ac.jp/icrc2003/PROCEEDINGS/PDF/295.pdf

Measurement of the atmospheric muon spectrum from 20 to 3000 GeV

The atmospheric muon spectrum between 20 and 2000 GeV was measured with the L3 magnetic muon spectrometer for zenith angles ranging from 0 to 58 degrees. Due to the large data set and the good detector resolution, a precision of 2.6% at 100 GeV was achieved for the absolute normalization of the vertical muon flux. The momentum dependence of the ratio of positive to negative muons was obtained between 20 and 630 GeV.

Measurement of the atmospheric muon spectrum from 20 to 2000 GeV

Absolute measurement of the vertical cosmic ray muon intensity at 3 – 50 GeV/c near sea level☆

Spectral dependence of the millimeter wavelength extinction due to two fibrous aerosols were measured over a frequency range spanning the primary attenuation peak. For contrast, two conductivities were selected, one representing polyacrylonitrile (PAN) graphite and the other is a metal-coated version incorporating the PAN core. Aerosol densities were measured to determine the mass-specific values of extinction. Aerosol length and diameter distributions were measured to provide parameters for comparison with theory. Both measurements and theory show a much stronger attenuation resonance for the higher conductivity material. At the resonance frequency, for which the particle length is approximately one-half the wavelength, the extinction efficiencies differ by about a factor of 3.

A.V. Jelinek

Papers

Absolute measurement of the vertical cosmic ray muon intensity at 3 – 50 GeV/c near sea level☆

Millimeter Wavelength Prime Resonance Spectra for High and Low-Conductivity Fibrous Aerosols