M. Aglietta et al., THE HIGH-ENERGY MUON SPECTRUM IN EXTENSIVE AIR SHOWERS - FIRST DATA FROM LVD AND EAS-TOP AT GRAN-SASSO, Astroparticle physics, 9(3), 1998, pp. 185-192
We present evidence for a dependence of the average deep underground m
uon energies on shower size in the coincident EAS-TOP and LVD data at
the Gran Sasso laboratories. The measured relation agrees with a mixed
chemical composition of the cosmic ray primary spectrum at energies a
round 10(15) eV. (C) 1998 Elsevier Science B.V.