Parametric analysis of Cherenkov light LDF from EAS in the range 30-3000 TeV for primary gamma rays and nuclei

TL;DR

This paper introduces a simple parametric 'knee-like' model for Cherenkov light LDF in EAS, enabling improved analysis of gamma rays and cosmic rays above tens of TeV, with applications in background suppression and primary particle identification.

Contribution

The paper presents a new 'knee-like' approximation for Cherenkov LDF that accurately fits individual EAS curves across a wide radial range, enhancing data analysis in high-energy gamma-ray and cosmic ray experiments.

Findings

The 'knee-like' approximation fits individual LDFs with high accuracy.

The model effectively distinguishes primary gamma rays from proton background.

Application improves primary particle identification in EAS measurements.

Abstract

A simple 'knee-like' approximation of the Lateral Distribution Function (LDF) of Cherenkov light emitted by EAS (extensive air showers) in the atmosphere is proposed for solving various tasks of data analysis in HiSCORE and other wide angle ground-based experiments designed to detect gamma rays and cosmic rays with the energy above tens of TeV. Simulation-based parametric analysis of individual LDF curves revealed that on the radial distance 20-500 m the 5-parameter 'knee-like' approximation fits individual LDFs as well as the mean LDF with a very good accuracy. In this paper we demonstrate the efficiency and flexibility of the 'knee-like' LDF approximation for various primary particles and shower parameters and the advantages of its application to suppressing proton background and selecting primary gamma rays.