Particle-vibration coupling effects on Gamow-Teller transition and beta-decay of magic nuclei

by Dr Yifei Niu (INFN, Milano and China Academy of Engineering Physics)

Thursday 30 Jul 2015, 13:30 → 14:30 Asia/Tokyo

Room 433 in Main Research Building (RIKEN Wako)

Date: Jul 30 (Thu) Time: 13:30 - Place: Main Research bldg. 433 Speaker: Yifei Niu (INFN, Milano & China Academy of Engineering Physics) Title: Particle-vibration coupling effects on Gamow-Teller transition and beta-decay of magic nuclei Abstract: Nuclear beta-decay plays an important role not only in nuclear physics but also in astrophysics and particle physics. Random-phase approximation (RPA) calculations based on different energy density functionals are widely used for the calculation of beta-decay half-lives. However, within this framework the half-lives of magic nuclei are usually overestimated. To overcome this problem, the particle-vibration coupling (PVC) effect is included on top of the RPA model [1]. The RPA+PVC model has also been used to investigate the Gamow-Teller resonance of 208Pb. Through the comparison with the experimental data, we can confirm that our model gives a good description of the lineshape of the strength function, and reproduces particularly well the measured width [2]. Then the beta-decay half-lives of 34Si, 68Ni, 78Ni, and 132Sn are studied within the present model [3]. It is found that the low-lying GT strength is shifted downwards with the inclusion of the PVC effect, and as a consequence, the half-lives are reduced due to the increase of the phase space available for beta-decay. In some cases, this leads to a very good agreement between theoretical and experimental lifetimes; this happens in particular for the Skyrme force SkM*, that can also reproduce the line shape of the high energy GT resonance. [1] Y. F. Niu, G. Colo, M. Brenna, P. F. Bortignon, and J. Meng, Phys. Rev. C 85, 034314 (2012). [2] Y. F. Niu, G. Colo, and E. Vigezzi, Phys. Rev. C 90, 054328 (2014). [3] Y. F. Niu, Z. M. Niu, G. Colo, and E. Vigezzi, Phys. Rev. Lett. 114, 142501 (2015). See more QHP seminars