A-DEPENDENCE OF Z-SCALING

The A-dependence of z-scaling in inclusive hadron production in pA collisions at high transverse momenta is studied. The concept of z-scaling based on the fundamental principles of Nature such as self-similarity, locality, scale relativity and fractality reflecting the general features of particle interactions is applied for the description of processes of hadron production in pA collisions. The scaling function ψ is expressed via the invariant cross-section Ed3σ/dq3 and the average multiplicity density dN/dη of particles produced at pseudorapidity η=0 in the corresponding nucleon–nucleon interaction. The independence of the function ψ(z) on the center-of-mass energy for particle production near 90° in the NN c.m. system for different nuclei from D up to Pb is shown. The scale transformation z→az, ψ→a-1ψ is used to determine the A-dependence of the transformation parameter a. Based on the properties of z-scaling the dependence of the cross-sections for the π±, K±, and hadrons produced in pA collisions on transverse momentum q⊥ in the central region (η=0) at RHIC energies is predicted.