Key points are not available for this paper at this time.
The present study is based on a sample of 407 775 single muons and 12 559 muon bundles with zenith angles smaller than 60^, observed in the 12. 3m6m6m Fr\'ejus proton-decay detector, at a depth of 4850 hg/cm^2. The variation of the vertical muon intensity with depth is given. Using a maximum-likelihood method, the muon lateral distribution of underground bundles is investigated as a function of muon multiplicity and zenith angle. The same method yields the true multiplicity distribution at the site depth, corrected for all detection effects.
Berger et al. (Sun,) studied this question.