M. Ambrosio et al., THE OBSERVATION OF UP-GOING CHARGED-PARTICLES PRODUCED BY HIGH-ENERGYMUONS IN UNDERGROUND DETECTORS, Astroparticle physics, 9(2), 1998, pp. 105-117
An experimental study of the production of up-going charged particles
in inelastic interactions of down-going underground muons is reported,
using data obtained from the MACRO detector at the Gran Sasso Laborat
ory. In a sample of 12.2 x 10(6) single muons, corresponding to a dete
ctor lifetime of 1.55y, 243 events are observed having an up-going par
ticle associated with a down-going muon. These events are analysed to
determine the range and emission angle distributions of the up-going p
article, corrected for detection and reconstruction efficiency. Measur
ements of the muon neutrino flux by underground detectors are often ba
sed on the observation of through-going and stopping muons produced in
v(mu) interactions in the rock below the detector. Up-going particles
produced by an undetected down-going muon are a potential background
source in these measurements. The implications of this background for
neutrino studies using MACRO are discussed. (C) 1998 Elsevier Science
B.V.