# Background rejection method for tens of TeV gamma-ray astronomy applicable to wide angle timing arrays

## TL;DR

This paper introduces a background rejection method for high-energy gamma-ray astronomy using a knee-like approximation of Cherenkov light distributions, enhancing discrimination capabilities in wide angle timing arrays.

## Contribution

It applies a knee-like approximation technique to background rejection in high-energy gamma-ray arrays, demonstrating improved performance with multivariable analysis.

## Key findings

- High background rejection levels achieved with the knee-like approximation.
- Multivariable approach effectiveness depends on the number of hit detectors.
- Method applicable to current and future wide angle Cherenkov arrays.

## Abstract

A 'knee-like' approximation of Cherenkov light Lateral Distribution Functions, which we developed earlier, now is used for the actual tasks of background rejection methods for high energy (tens and hundreds of TeV) gamma-ray astronomy. In this work we implement this technique to the HiSCORE wide angle timing array consisting of Cherenkov light detectors with spacing of 100 m covering 0.2 km$^2$ presently and up to 5 km$^2$ in future. However, it can be applied to other similar arrays. We also show that the application of a multivariable approach (where 3 parameters of the knee-like approximation are used) allows us to reach a high level of background rejection, but it strongly depends on the number of hit detectors.