Today, we have a variety of reactions at hand that can be used to
multi-fragment nuclei. In many of these reactions even several sources of
fragments can be discerned and characterized.
There is overwhelming evidence that these sources of fragments are hot. It is
already less clear whether heat by itself is sufficient to initiate the
fragment decay. What causes fragmentation, and when and how are the fragments
(pre)formed? These questions have remained as much a challenge as the
complementary class of questions to which they are related: What observations
derive their significance from the liquid-gas phase behavior of extended
nuclear matter? And, can we observe a phase transition in finite nuclei?
Recent developments, largely coming from complex analyses of data sets
measured in 4-pi-type experiments as well as from calculations based on
advanced theoretical concepts, will be discussed.Comment: 13 pages, with 8 included figures; To appear in the proceedings of
the NN 2000 conference; Also available from
http://www-kp3.gsi.de/www/kp3/aladin_publications.htm
