Phenomenological analysis of the channels of the production of three and four alpha particles in ¹⁶Op collisions at 3.25 GeV/c per nucleon

A phenomenological analysis of the channels of the production of three and four alpha particles in (16)Op collisions at 3.25 GeV/c per nucleon is performed for the first time under conditions of 4pi geometry. The experimentally observed azimuthal asymmetries and collinearity are described on the basis of a phenomenological model that assumes that the excitation of the nucleus involved is peripheral and that its decay is statistical. It is shown that the azimuthal asymmetries in question are due to the transverse motion of the fragmenting nucleus. The mean transverse momentum of alpha particles and the collinearity of their emission in the reaction plane are found to be independent of the transverse-momentum transfer to the nucleus involved. (C) 2004 MAIK "Nauka/Interperiodica".