Scaling of anisotropic flow and momentum-space densities tor light particles in intermediate energy heavy ion collisions

Anisotropic flows (upsilon(2) and upsilon(4)) of light nuclear clusters are studied by isospin-dependent quantum molecular dynamics model for the system of Kr-86 + Sn-124 at intermediate energy and large impact parameters. Number-of-nucleon scaling of the elliptic flow (upsilon(2)) are demonstrated for the light fragments up to A = 4, and the ratio of upsilon(4)/upsilon(2)(2) shows a constant value of 1/2. In addition, the momentum-space densities of different clusters are also surveyed as functions of transverse momentum, in-plane transverse momentum and azimuth angle relative to the reaction plane. The results can be essentially described by momentum-space power law. All the above phenomena indicate that there exists a number-of-nucleon scaling for both anisotropic flow and momentum-space densities for light clusters, which can be understood by the coalescence mechanism in nucleonic degree of freedom for the cluster formation. (c) 2006 Elsevier B.V. All rights reserved.