Evidences for strangelet presence in Primary Cosmic Rays

The recent results of experiment “Hadron” which was carried out at Tien-Shan Station in 1985–91 are discussed. The combining of extensive air shower array and large emulsion chamber has permitted to receive new experimental data on sharp scaling violation at energies ≥10¹⁵ eV (1 PeV). Data show strong hardness of hadron energy spectra in EAS cores for primary energies ≥3 PeV. The EAS electron lateral distribution function also exhibits the same energy dependence in interval 1–10 PeV. The EAS muon component also shows changing of energy dependence at 10 PeV. These data permit to discuss a model in which sharp scaling violation is connected with EAS spectrum “knee”. A hypothesis of strangelet presence in PCR is discussed. The flow of strangelet component is estimated to be about 1 m^?2 · year^?1.