Muon “depth-intensity” relation measured by the LVD underground experiment and cosmic-ray muon spectrum at sea level

We present an analysis of muon events with all muon multiplicities collected during 21804 h of operation of the first Large Volume Detector tower. The measured angular distribution of muon intensity has been converted to the “depth–vertical-intensity” relation in the depth range from 3 to 12 km w.e. The analysis of this relation allowed us to derive the power index $\gamma$ of the primary all-nucleon spectrum: $\gamma =2.78\mathrm{}\pm \mathrm{0.05.}$ The “depth–vertical-intensity” relation has been converted to standard rock and the comparison with the data of other experiments has been done. We also present the derived vertical muon spectrum at sea level.