Rapidity distributions in unequal nuclei collision at high energies and hydrodynamic model

The mechanism of high-energyA′?A collisions (A>A′, A′ ^1/3?1) and the space-time evolution of the fluid formed in the collision are analysed. The corresponding 1+1 dimensional hydrodynamic equations are set up. The average rapidity distributions are estimated and compared with cosmic ray data. The origin of the unsymmetry of rapidity distributions is explained.