抄録
Mu-meson component, observed underground, of the extensive air shower is studied, which has come from the nuclear cascade of the shower core in the ground and possibly shows high concentration of mu-mesons below the ground. The total number of them can be estimated independently of energy and multiplicity distributions of secondary particles of the elementary collision each of shower particles undergoes, and also independently of some fluctuations. It is only because they depend upon the whole feature of the nuclear cascade in the shower core.
Experimental data of the multiple penetrating particles (M.P.P.), whose feature is the high concentration of mu-mesons, could not be interpreted in terms of those mu-mesons, i. e., decay products within the nuclear cascades in the ground initiated by impinging nucleons of high energy in the air shower cores, even though the possible contribution of the K-meson and Hyperon production in the high energy collisions within nuclear cascades is taken into consideration.
