We present in detail a theoretical model for fragmentation reactions of thr
ee-body halo nuclei. The different reaction mechanisms corresponding to the
different processes are described and discussed. Coulomb and nuclear inter
actions are simultaneously included and the method is therefore applicable
for any target, light, intermediate and heavy. Absolute values of many diff
erential cross sections are then available as function of beam energy and t
arget. We apply the method to fragmentation of He-6 and Li-11 on C, Cu and
Pb. A large variety of observables, cross sections and momentum distributio
ns, are computed. In almost all cases we obtain good agreement with the ava
ilable experimental data. (C) 2001 Elsevier Science B.V. All rights reserve
d.