Programme

O.14 -- Oral, VCTP-45

Date: Tuesday, 13 October 2020

Time: 16:20 - 16:40

Role of pairing correlation in the radiative strength function

L. Tan Phuc (1), N. Quang Hung (1), N. Dinh Dang (2), L. T. Quynh Huong (3), N. Ngoc Anh (4), N. Ngoc Duy (5), L. Ngoc Uyen (6), and N. Nhu Le (7)

(1) Institute of Fundamental and Applied Sciences, Duy Tan University, (2) Quantum Hadron Physics Laboratory, RIKEN Nishina Center for Accelerator-Based Science, RIKEN, Japan. (3) Department of Natural Science and Technology, University of Khanh Hoa (4) Dalat Nuclear Research Institute, Vietnam Atomic Energy Institute (5) Department of Physics, Sungkyunkwan University (6) Faculty of Physics, Ho Chi Minh City University of Education (7) Faculty of Physics, University of Education, Hue University

The enhancement of radiative strength function (RSF) in the region of low $\gamma$-rays energy (E$\gamma$ ≤ 12 MeV), which is caused by the pygmy dipole resonance (PDR), is treated within the phonon damping model (PDM) plus exact pairing (EP) at finite temperature without adding any extra PDR fitting peak. The numerical calculations performed for 161-163 Dy show that, because of the effect of exact thermal pairing, the EP+PDM can describe reasonably well the total RSF data in both low- and high-energy regions of γ-rays. Consequently, as compared to the conventional description within the phenomenological generalized Lorentzian (GLO) and standard Lorentzian (SLO) models, the EP+PDM calculations are free from at least six free parameters. This indicates the important role of microscopic approaches towards the precise prediction of the RSF. In particular, temperature is found to have significant contributions to the RSF below the neutron separation energy, questioning again the validity of the Brink-Axel hypothesis

Presenter: Le Tan Phuc