Composite particle emission in relativistic heavy ion collisions

Inclusive spectra of d, t, and ³He have been measured over a wide range of fragment angles and energies. The observed spectra are well reproduced by the “coalescence model” with a coalescence radius p₀ which is independent of beam energies and which decreases as the sizes of the target-projectile combinations increase. The sizes of the interaction regions have been derived from these p₀ values. The experimental cross sections generally deviate from predictions of the firestreak model.