Atmospheric neutrinos in MACRO

Results from MACRO on atmospheric neutrinos are presented. For high energy events, ∼ 100 GeV, a fit to the total measured flux and angular distributions yield a poor fit without the inclusion of neutrino oscillations. The data favors νμ →ντ oscillations with large mixing angle and Δm2 ∼ 2.5x10-3 eV2 and disfavors a sterile neutrino hypothesis at the ∼ 2σ level. Low energy events, both stopping and internal, have also been analyzed. In MACRO, statistics are poorer for this type of event. The results for Internal Upward, and Internal Downward + Upwardgoing Stopping events also have a deficit with respect to expectation (no oscillations), but there is no observed zenith angle distortion. Detailed fits to the low energy data are also in agreement with the hypothesis of νμ → ντ oscillations with large mixing angle and 10-3 < Δm2 < 2x10-2 eV2 The fit with no oscillations has a probability of less than 3%. Overall, a consistent scenario arises from both high and low energy MACRO atmospheric neutrino events