GeV Proton Detection in the 8 November 2000 Solar Event

In this study, we analyze the L3 precision muon spectrometer data from November 2000. The results showed that a 4.7σ muon excess appeared at a time coincident with the solar flare of 8 November 2000. This muon excess corresponded to primary protons above 40 GeV, coming from a sky cell of solid angle 0.048 sr. The probability of being a background fluctuation was estimated to be about 0.1%. It is interesting and noteworthy that an M-class solar flare may also accelerate solar protons to such high energies.