Gamma-ray astronomy with a large muon detector in the ARGO-YBJ experiment

The ARGO‐YBJ experiment, currently under construction at the YangBaJing Laboratory (Tibet, P.R. China, 4300 m a.s.l.), could be upgraded with a large (∼ 2500 m2) muon detector both to extend the sensitivity to γ‐ray sources to energies greater than ∼ 20 TeV and to perform a cosmic ray primary composition study. In this paper we present an evaluation of the rejection power for proton‐induced showers achievable with the upgraded ARGO‐YBJ detector. Minimum detectable γ‐ray fluxes are calculated for different experimental setups.