ANALYSIS OF THE MACRO EXPERIMENT DATA TO COMPARE PARTICLE ARRIVAL TIMES UNDER GRAN SASSO

The claim of a neutrino velocity different from the speed of the light, made in September 2011 by the Opera experiment, suggested the study of the time delays between TeV underground muons in the Gran Sasso laboratory using the old data of the MACRO experiment, ended in 2000. This study can also give hints on new physics in the particle cascade produced by the interaction of a cosmic ray with the atmosphere.

Geant4 Simulation Study of Deep Underground Muons: Vertical Intensity and Angular Distribution

Underground muon intensities up to 10000 m.w.e. and angular distribution up to 6500 m.w.e. in standard rock have been investigated using Geant4 simulation package. Muons with energies above 100 GeV were distributed from the ground level taking into account the muon charge ratio of~1.3 at sea level. The simulated differential muon intensities are in good agreement with the intensities given in the literature. Furthermore, the simulation results for the integrated intensities are consistent with the experimental data, particularly at depths above 4000 m.w.e., where the simulation gives slightly smaller intensities than the experimental ones. In addition, the simulated exponentnat different underground depths agrees well with the experimental points, especially above~2000 m.w.e.