Seasonal Variation of Atmospheric Leptons as a Probe of Charm

The intensity of TeV atmospheric muons and neutrinos depends on the temperature in the stratosphere. We show that the energy dependence in the 100 TeV range of the correlation with temperature is sensitive to the fraction of muons and neutrinos from decay of charmed hadrons. We discuss the prospects for using the temperature effect as observed in gigaton neutrino detectors to measure the charm contribution.

Figure 1

Top: Fraction of muon-neutrinos from pion decay, kaon decay, and charm decay (RQPM [24]) as a function of neutrino energy. Bottom: Same for muons. Solid lines are for vertical and dashed lines for 60° (see text for discussion).

Figure 2

Differential correlation coefficient as a function of lepton energy for near vertical muons and muon neutrinos. Solid lines, no charm; dashed lines, with RQPM charm [24].