THERMAL EFFECTS ON ISOSCALAR GIANT-RESONANCE ENERGIES IN HOT NUCLEI

The thermal effects on the energies of the isoscalar giant multipole r esonances of hot nuclei are discussed and an approximate formula for t he energy as a function of temperature is derived via a hydrodynamic t heory. The energy difference between the isoscalar giant multipole res onance of a hot nucleus and its ground-state resonance depends on the competition between the volume expansion and the increase of the avera ge kinetic energy per nucleon of hot nuclei, which lower and raise the resonance energy, respectively, and nearly counteract each other in m agnitude. The variation of the isoscalar giant resonance energy with t emperature is very small.