Seasonal Variations of the Atmospheric Muon Neutrino Spectrum measured with IceCube

This study presents an energy-dependent analysis of seasonal variations in the atmospheric muon neutrino spectrum, using 11.3 years of data from the IceCube Neutrino Observatory. By leveraging a novel spectral unfolding method, we explore the energy range from 125 GeV to 10 TeV for zenith angles between 90{} to 110{}, corresponding to the Antarctic atmosphere. Our findings reveal that the seasonal variation amplitude decreases with energy reaching (-4.6 ± 1.1)% during Austral winter and increases (+3.9 ± 1.2)% during Austral summer relative to the annual average at 10TeV. While the unfolded flux exceeds the model predictions by up to 30%, the differential measurement of seasonal variations remains unaffected. The measured seasonal variations of the muon neutrino spectrum are consistent with theoretical predictions using the MCEq code and the NRLMSISE-00 atmospheric model.