15964309
Mutually compensative pseudo solutions of primary energy spectra in the knee region
Abstract The problem of the uniqueness of solutions during the evaluation of primary energy spectra in the knee region using an extensive air shower (EAS) data set and the EAS inverse approach is investigated. It is shown that the unfolding of primary energy spectra in the knee region leads to mutually compensative pseudo solutions. These solutions may be the reason for the observed disagreements in the elementary energy spectra of cosmic rays in the 1–100 PeV energy range obtained from different experiments.
118956991
Primary Energy Spectra and Elemental Composition. GAMMA Experiment
On the basis of the Extensive Air Shower data observed by the GAMMA experiment the energy spectra and elemental composition of the primary cosmic rays have been derived in the 1-100 PeV energy range. Reconstruction of the primary energy spectra is carried out in the framework of the SIBYLL and QGSJET interaction models and the hypothesis of the power-law steepening primary energy spectra. All presented results are derived taking into account the detector response, reconstruction uncertainties of EAS parameters and fluctuation of EAS development.
15515326
Galactic diffuse gamma-ray flux at the energy about 175 TeV
We present an upper limit of galactic diffuse gamma-ray flux, measured with the GAMMA experiment at energy about 175 TeV. The results were obtained using selection of muon poor extensive air showers at mountain level (700 g/cm 2 , Mt. Ara- gats, Armenia) for 5 GeV muon energy threshold. An upper limit for the differential flux at energy E ≃ 175 +25 20 TeV is equal to (5.8 − 7.0) � 10 12 (ergm 2 � ssr) 1 for 95% confidence level 1 .
17568500
An all-particle primary energy spectrum in the 3–200 PeV energy range
We present an all-particle primary cosmic-ray energy spectrum in the 3 × 10 6 – 2 × 10 8 GeV energy range obtained by a multi-parametric event-by-event evaluation of the primary energy. The results are obtained on the basis of an expanded EAS data set detected at mountain level (700 g cm −2 )b y the GAMMA experiment. The energy evaluation method has been developed using the EAS simulation with the SIBYLL interaction model taking into account the response of GAMMA detectors and reconstruction uncertainties of EAS parameters. Nearly unbiased (<5%) energy estimations regardless of a primary nuclear mass with an accuracy of about 15–10% in the 3 × 10 6 –2 × 10 8 GeV energy range respectively are attained. An irregularity (‘bump’) in the spectrum is observed at primary energies of ∼7.4 × 10 7 GeV. This bump exceeds a smooth power-law fit to the data by about 4 standard deviations. By not rejecting the stochastic nature of the bump completely, we examined the systematic uncertainties of our methods and conclude that they cannot be responsible for the observed feature.
14618248
Anisotropy analysis of EAS data in the knee region
Based on MAKET-ANI EAS data the distributions of equatorial coordinates of EAS core directions are obtained in the knee region. Anisotropy of primary cosmic rays is displayed only by declination equatorial coordinates (20+/-3 degrees) at primary energies more than 5-10 PeV. The fraction of anisotropic component turns out ~10% in the knee region.
176947993
Hard processes and ANI experiment
117993503
Search Capability for eta ---> nu(e, tau) anti-nu(e, tau) Decays in Cubic Kilometer Neutrino Detectors
We investigate the discovery potential of cubic-kilometer neutrino observatories such as IceCube to set stringent limits on the forbidden decays η → v e v e and η → v τ v τ . The signatures for these decays are cascade events resulting from the charged-current reactions of v e , v τ , v e , and v τ on nuclei in such detectors. Background cascade events are mainly due to v e 's from atmospheric μ, K + , and K 0 S decays and to a lesser extent from atmospheric v μ neutral-current interactions with nuclei. A direct upper limit for the branching ratio η → v e,τ v e,τ of 6.1 × 10 -4 at 90% CL can be achieved.