Atmospheric neutrinos and the knee of the cosmic ray spectrum

Abstract

The nature of the knee in the all-particle spectrum of cosmic rays remains subject of much investigation, especially in the aftermath of recent measurements claiming the detection of a knee-like feature in the spectrum of the light component of cosmic rays at energy ∼ 700 TeV, at odds with the standard picture in which the knee in the all-particle spectrum is dominated by light cosmic rays. Here we investigate the implications of this and other scenarios in terms of the measured flux of atmospheric neutrinos. In particular we discuss the possibility that the spectrum of atmospheric neutrinos in the region 50 TeV may provide information about the different models for the mass composition in the knee region. We investigate the dependence of the predicted atmospheric neutrino flux on the shape of the light cosmic ray spectra and on the interaction models describing the development of showers in the atmosphere. The implications of all these factors for the identification of the onset of an astrophysical neutrino component are discussed.

The low rate of Galactic pevatrons

“…7 P e V 1 P e V 2 Pe V 3 Pe V Figure 3: Maximum energy of accelerated protons at the transition between the ED and ST phase of a SNR from a type II * progenitor, for different SN total explosion energy E SN and ejecta mass M ej , for a RSG mass-loss rateṀ = 10 −4 M yr −1 and ξ = 0.1. [34], PAMELA [35], CALET LE and HE [36], DAMPE [37], ARGO-YBJ [38], ARGO fit for protons [39], Tibet [40] and KASCADE [41]. The yellow areas correspond to the typical level of measured protons.…”

“…The detection of some of these astrophysical sources in the PeV range by current and future instruments [52,53] might provide precious clues in this respect. Type Ia Type II Type II * [34], PAMELA [35], CALET LE and HE [36], DAMPE [37], ARGO-YBJ [38], ARGO fit for protons [39], Tibet [40] and KASCADE [41]. The yellow areas correspond to the typical level of measured protons.…”

Measurement of the diffuse astrophysical muon-neutrino spectrum with ten years of IceCube data

“…Change of γ astro Change of Φ astro ∆γ CR ∆LLH Gaisser-Hillas, H4a [10] --0.06 -Gaisser-Stanev-Tilav, GST-4gen [14] -0.007 -0.115 0.01 4.4 GSF-beta [15] -0.007 -0.234 0.03 1.8 Mascaretti et al (KASCADE w. cutoff) [16] 0.015 -0.235 -0.04 -2.1 Mascaretti et al (ARGO-YBJ w. cutoff) [16] -0.011 0.116 0.02 -1.9 Table 2 Impact of different primary cosmic-ray flux models (CR-models) used for the calculation of atmospheric fluxes on the astrophysical fit-parameters compared to the baseline model H4a.…”

Expectations from the assumption of hadron-hadroncollisions for high energy neutrinos

“…Following [10], we compute the atmospheric neutrino flux with MCEq [11], adopting the most recent 2.3c version of SYBILL [12], and a primary CR flux defined as follows:…”