The atmospheric muon charge ratio: a probe to constrain the atmospheric $\nu_{\mu}$/$\bar{\nu}_{\mu}$ ratio

The atmospheric muon charge ratio, defined as the number of positive over negative charged muons, is an important observable to shed light on the physics of cosmic ray interactions in atmosphere. It allows studying the features of high-energy hadronic interactions in the forward region and the composition of primary cosmic rays. In particular, the TeV muon charge ratio provides sensitivity to the charge ratio of high energy kaons, the principal parents of atmospheric neutrinos. In this paper the results from the OPERA experiment in the TeV energy range are reviewed