天体物理学と航空宇宙技術

Flux Determination through Ultra High Energy Muons by Using Pair-Meter Technique

Abstract

Sharda Pandey and Satendra K Chauhan

The cosmic ray spectrum exhibits two transition regions. The steepening of the spectrum occurs around 106 GeV known as knee region and the flattening of the spectrum occurs around 109 GeV known as ankle region. The reason of this transition in cosmic ray spectrum is not known. When the cosmic rays interact with the atmospheric nuclei they produce muons. The decay of long live d mesons at GeV energies contributes to the conventional muon fluxes. At higher energies, some contribution to the fluxes of muons will come from the interactions of short lived particles with the atmospheric nuclei. This contribution will give rise to prompt muon fluxes. In order to understand the prompt contribution to the neutrino and muon fluxes, we have selected high energy (TeV) muons for our studies. The dominant processes for this energy range are pair production and bremsstrahlung. For this energy region, we are using pair-meter technique to achieve a reliable reconstruction of the muon energies. Here we are taking a detector with dimensions 15.6 m × 15.6 m × 78 m and which is placed 705 m underground from the surface of the earth. This study will help us to understand the contribution of prompt muon fluxes in higher energy region. It will also help us in understanding the possible compositional changes in the cosmic ray spectrum.