Seasonal variations of the atmospheric muon neutrino spectrum measured with IceCube

Abstract This study presents an analysis of seasonal variations in the atmospheric muon neutrino flux, 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 from $${90}^{\circ }$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mrow> <mml:mn>90</mml:mn> </mml:mrow> <mml:mo>∘</mml:mo> </mml:msup> </mml:math> to $${110}^{\circ }$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mrow> <mml:mn>110</mml:mn> </mml:mrow> <mml:mo>∘</mml:mo> </mml:msup> </mml:math> , corresponding to the Antarctic atmosphere. Our findings reveal that the differential measurement of the amplitudes of the seasonal variation is consistent with an energy-dependent decrease reaching ( $$-\,4.5$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mo>-</mml:mo> <mml:mspace/> <mml:mn>4.5</mml:mn> </mml:mrow> </mml:math> ± 1.2)% during Austral winter and increase to (+ 3.9 ± 1.3)% during…