Temperature dependence of a spreading width of giant dipole resonance in neutron-rich nuclei

Abstract A temperature dependence of the spreading width of a giant dipole resonance is studied in the framework of the Quasiparticle-Phonon Model extended to finite temperature using a formalism of the Thermo Field Dynamics. Numerical calculations are performed for 120 Sn and the neutron-rich double-magic isotope 132 Sn It is found that the dispersion of the E1 strength function σ increases with temperature.