# Attenuation effect and neutrino oscillation tomography

## TL;DR

This paper investigates the attenuation effect in neutrino oscillation signals caused by matter density structures, providing a graphic method to analyze and compute the impact on Earth tomography using low energy neutrinos.

## Contribution

It introduces a graphic approach to quantify the attenuation effect in neutrino oscillations and explores its implications for Earth tomography with low energy neutrinos.

## Key findings

- Attenuation results from averaging oscillations and small matter effects.
- The graphic method enables explicit calculations of attenuation effects.
- Attenuation significantly influences neutrino-based Earth tomography.

## Abstract

Attenuation effect is the effect of weakening of contributions to the oscillation signal from remote structures of matter density profile. The effect is a consequence of integration over the neutrino energy within the energy resolution interval. Structures of a density profile situated at distances larger than the attenuation length, $\lambda_{att}$, are not "seen". We show that the origins of attenuation are (i) averaging of oscillations in certain layer(s) of matter, (ii) smallness of matter effect: $\epsilon \equiv 2EV/\Delta m^2 \ll 1$, where $V$ is the matter potential, and (iii) specific initial and final states on neutrinos. We elaborate on the graphic description of the attenuation which allows us to compute explicitly the effects in the $\epsilon^2$ order for various density profiles and oscillation channels. The attenuation in the case of partial averaging is described. The effect is crucial for interpretation of oscillation data and for the oscillation tomography of the Earth with low energy (solar, supernova, atmospheric, {\it etc.}) neutrinos.