Measurement of the atmospheric muon depth intensity relation with the NEMO Phase-2 tower

TL;DR

This paper reports the measurement of atmospheric muon flux at great depths using the NEMO Phase-2 detector, providing data up to 13 km water equivalent and comparing results with simulations and theories.

Contribution

It presents the first measurement of the muon depth intensity relation up to 13 km water equivalent using the NEMO Phase-2 tower, including systematic uncertainty analysis.

Findings

Muon flux measured up to 13 km water equivalent

Results agree with Monte Carlo simulations and theoretical models

Systematic uncertainties evaluated and included

Abstract

The results of the analysis of the data collected with the NEMO Phase-2 tower, deployed at 3500 m depth about 80 km off-shore Capo Passero (Italy), are presented. Cherenkov photons detected with the photomultipliers tubes were used to reconstruct the tracks of atmospheric muons. Their zenith-angle distribution was measured and the results compared with Monte Carlo simulations. An evaluation of the systematic effects due to uncertainties on environmental and detector parameters is also included. The associated depth intensity relation was evaluated and compared with previous measurements and theoretical predictions. With the present analysis, the muon depth intensity relation has been measured up to 13 km of water equivalent.