$P_{\gamma h}^{\alpha}$: a new variable for $\gamma / {\rm h}$ discrimination in large gamma-ray ground arrays

TL;DR

This paper introduces a new variable, $P_{\gamma h}^{\alpha}$, to improve gamma-ray discrimination from cosmic ray background in large ground arrays, showing promising results for high-energy observations.

Contribution

The paper proposes a novel variable $P_{\gamma h}^{\alpha}$ that enhances gamma/hadron discrimination in large cosmic ray detectors, especially at multi-TeV energies.

Findings

The new variable improves gamma-ray discrimination power.

Results are promising for both low and high station occupancy scenarios.

Potential for application in current and future gamma-ray observatories.

Abstract

In this letter, a new strategy to enhance the discrimination of high energy gamma rays from the huge charged cosmic rays background in large cosmic rays ground arrays is presented. This strategy is based on the introduction of a new simple variable, $P_{\gamma h}^{\alpha}$, which combines the probability of tagging muons and/or very energetic particles in each single array station. The discrimination power of this new variable, particularly important for and above multi-TeV energies, is illustrated for a few specific examples in the case of a hypothetical water Cherenkov detector cosmic ray array, both in the case of low and high particle stations occupancy. The results are very encouraging and hopefully will be demonstrated in the present and future gamma-ray Observatories.