Speaker
Description
Finite-temperature effects play a crucial role in shaping exotic nuclear excitations. Thermal unblocking and the weakening of pairing correlations can significantly modify excitation modes of different multipolarities, leading to the emergence of strength that is suppressed at zero temperature. A microscopic description of these effects is therefore important for nuclear structure studies and for astrophysical applications involving hot, neutron-rich systems [1–3].
In this talk, I present a unified study of nuclear excitations at finite temperature based on the finite-temperature relativistic quasiparticle random-phase approximation within the covariant energy density functional framework. I first examine how temperature affects electric and magnetic excitation modes, with emphasis on the role of pairing reduction and thermally unblocked configurations. I then discuss the temperature evolution of the pygmy dipole resonance and the emergence of thermally induced low-energy dipole strength in neutron-rich nuclei [4]. Finally, I address the consequences for electromagnetic γ-ray strength functions, highlighting the redistribution and enhancement of low-energy E1 and M1 strength relevant for hot stellar environments [5].
References
[1] E. Yüksel, G. Colò, E. Khan, Y. F. Niu, and K. Bozkurt, “Multipole excitations in hot nuclei within the finite temperature quasiparticle random phase approximation framework,” Phys. Rev. C 96, 024303 (2017).
[2] E. Yüksel, G. Colò, E. Khan, and Y. F. Niu, “Nuclear excitations within microscopic EDF approaches: Pairing and temperature effects on the dipole response,” Eur. Phys. J. A 55, 230 (2019).
[3] A. Kaur, E. Yüksel, and N. Paar, “Finite-temperature effects in magnetic dipole transitions,” Phys. Rev. C 109, 024305 (2024).
[4] A. Kaur, E. Yüksel, and N. Paar, “Hot pygmy dipole strength in nickel isotopes,” Phys. Rev. C 112, L051304 (2025).
[5] A. Kaur, E. Yüksel, and N. Paar, “Electric and magnetic γ-ray strength functions at finite temperature,” Phys. Rev. C 112, 014307 (2025).