# Atmospheric neutrinos and the knee of the Cosmic Ray spectrum

## TL;DR

This paper explores how atmospheric neutrino measurements around 50 TeV can shed light on cosmic ray composition models near the knee, considering recent conflicting observations and interaction models.

## Contribution

It analyzes the impact of cosmic ray composition and interaction models on atmospheric neutrino flux predictions and their role in identifying astrophysical neutrino signals.

## Key findings

- Atmospheric neutrino flux depends on cosmic ray composition models.
- Different interaction models significantly affect neutrino flux predictions.
- Neutrino measurements can help distinguish between cosmic ray models.

## 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 $\sim$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 $\gtrsim$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.