Primary cosmic rays are nucleons from outer space incident upon the Earth’s atmosphere. Their flux varies with energy E as \u1d438^(−\u1d6fe) in which the exponent assumes values between 2.5 and 3.2. We provide herein a framework to account for these values. We consider the particles’ kinetic temperature T and introduce a damping factor \u1d447^(−\u1d45a) to account for non head-on collisions. It is the presence of the index m which can provide values of γ
