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Recent measurements of the cosmic-ray electron (e-) and positron (e+) fluxesshow apparent excesses compared to the spectra expected by standard cosmic-ray(CR) propagation models in our galaxy. These excesses may be related toparticle acceleration in local astrophysical objects, or to dark matterannihilation/decay. The e+/e- ratio (measured up to ~100 GeV) increasesunexpectedly above 10 GeV and this may be connected to the excess measured inall-electron flux at 300-800 GeV. Measurement of this ratio at higher energiesis a key parameter to understand the origin of these spectral anomalies.Imaging Atmospheric Cherenkov Telescopes (IACT) detect electromagnetic airshowers above 100 GeV, but, with this technique, the discrimination betweenprimary e-, e+ and diffuse gamma-rays is almost impossible. However, the Moonand the geomagnetic field provide an incredible opportunity to separate these 3components. Indeed, the Moon produces a 0.5deg-diameter hole in the isotropicCR flux, which is shifted by the Earth magnetosphere depending on the momentumand charge of the particles. Below few TeV, the e+ and e- shadows are shiftedat >0.5deg each side of the Moon and the e+, e- and gamma-ray shadows arespatially separated. IACT can observe the e+ and e- shadows without directmoonlight in the field of view, but the scattered moonlight induces a very highbackground level. Operating at the highest altitude (2200m), with the largesttelescopes (17m) of the current IACT, MAGIC is the best candidate to reach alow energy threshold in these peculiar conditions. Here we discuss thefeasibility of such observations.

Observation of shadowing of the cosmic electrons and positrons by the Moon with IACT