Adiabatic expansion, local equilibrium and extended Maxwell distribution for fire-ball to describe multiple particle production (II).

The model of multiple particle production in [A. Ohsawa, Int. J. Mod. Phys. A (2023) 2350166.] assumes a fire-ball of a gas, consisting of grains, with the adiabatic and one-dimensional expansion, local equilibrium at the final state and the extended Maxwell distribution for the energy distribution of the grains. There are small and large p T (transverse momentum) processes for grains. The grain produces several hadrons to be observed in the experiments at the final state. The model describes well the pseudo-rapidity density distributions and the p T distributions at various incident energies. In this paper it is shown that the model reproduces well the incident energy dependences of 〈 p T 〉 (the average p T of produced particles), m c h (the charged multiplicity) and ρ 0 (the pseudo-rapidity density at η = 0). Furthermore it is shown that the inelasticity is almost energy-independent and K = 0. 5 in the energy region of s = 1 0 ∼ 1 0 4 GeV, and that the Feynman scaling law is violated. The model indicates that the fire-ball satisfies the conditions for quark-gluon plasma, that the grains of the large p T process may be identified with jets, and that p T 's of the grains in the large p T process are due to mutual collision of the grains during the one-dimensional expansion. [ABSTRACT FROM AUTHOR]