Cosmic ray 'knee' in the spectrum and proton-proton cross section from the point of view of new quarks

A possible explanation of the “knee” in the cosmic ray spectrum by the change in hadron-hadron interactions at the corresponding energy is discussed. It is shown that, at c.m. energies above 5 TeV, the total proton-proton cross sections obtained from cosmic ray experiments exceed the asymptotic fit made over the collider data. Such a rise of the cross sections favors the hypothesis about new chromodynamically charged degrees of freedom, the threshold of their creation being about \(\sqrt {^\mathcal{S} knee} \approx 2.3 TeV\). The properties of these new particles which are needed are discussed.