  Light neutralinos could be copiously produced from the decays of mesons
generated in cosmic-ray air showers. These neutralinos can be long-lived
particles in the context of R-parity violating (RPV) supersymmetric models,
implying that they could be capable of reaching the surface of the earth and
decay within the instrumental volume of large neutrino detectors. In this
letter, we use atmospheric neutrino data from the Super-Kamiokande experiment
to derive novel constraints for the RPV couplings involved in the production of
long-lived light neutralinos from the decays of charged $D$-mesons and kaons.
Our results highlight the potential of neutrino detectors to search for
long-lived particles, by demonstrating that it is possible to explore regions
of parameter space that are not yet constrained by any fixed-target nor
collider experiments.
