Nuclear isotope thermometry - art. no. 064607

We discuss different aspects which might influence temperatures deduced fro m experimental isotopic yields in the multifragmentation process. It is sho wn that fluctuations due to the finite size of the system and distortions-d ue to the decay of hot primary fragments conspire to blur the temperature d etermination in multifragmentation reactions. These facts suggest that calo ric curves obtained through isotope thermometers, which were taken as evide nce for a first-order phase transition in nuclear matter, should be investi gated very carefully.