Production of pions through the intermediate state called fireballs has been considered to study the energy distribution of pions in the fireball-rest system. Nikfi-R-type photoemulsion plates exposed to the 70-GeV proton beam of the Surpukhov Accelerator, Dubna, USSR, are used for this purpose. A graphical representation of the distribution of energies among the pions is shown. It is observed that this distribution closely resembles Planck's distribution of photons. Furthermore, this study reveals that the Maxwell–Boltzmann distribution deviates greatly from experimental observations. The average energy of the pions is found to be (0.770 ± 0.03) GeV.
Control of energy distribution of the proton beam with an oblique incidence of the laser pulse
