Theory Seminar

Ab Initio No Core Shell Model Study for Lighter NucleiONLINE ONLY

by Archana Saxena (Indian Institute of Technology Roorkee)

Europe/Berlin
Zoom (Meeting ID: 954 5378 3003, Passcode: theosem)

Zoom (Meeting ID: 954 5378 3003, Passcode: theosem)

Description

The ab initio no core shell model (NCSM) is one of the many body methods which gives precise results in nuclear theory. Recently, we have studied nuclear structure properties of N, O and F isotopes [1-2] with NCSM using inside nonlocal Outside Yukawa (INOY), CDB2K, N3LO and N2LOopt NN interactions. In INOY, the two body INOY interaction has the effect of three-body forces in terms of short range and nonlocality character present in it. We also compare the NCSM results with the phenomenological interactions using the shell model with core to test the predictive power of the ab initio nuclear theory. Overall, our NCSM results are consistent with the available experimental data for neutron rich nitrogen isotopes. In oxygen isotopes the drip line is also reproduced with the INOY NN interaction and over binding in g.s. energy is observed in our largest model space Nmax=6 (m-scheme dimension for 21O ∼3.36 × 109) for 18-21O isotopes. In general, the 3N interaction is required to get more accurate results. The other many body methods in which valence-space Hamiltonians derived with two ab initio approaches: in-medium similarity renormalization group (IM-SRG) and coupled-cluster effective interaction (CCEI) are used to calculate the nuclear observables like electric quadrupole moments, magnetic dipole moments and Gamow-Teller strength distributions for sd shell nuclei to test the predictive power of these ab initio effective interactions [3-4]. The results obtained with the phenomenological USDB Hamiltonian show reasonable agreements with the experimental data in comparison with the ab initio interactions.

References:
[1] Ab Initio No Core Shell Model Study of Neutron Rich Nitrogen Isotopes, A. Saxena, P. C. Srivastava, Progress of Theoretical and Experimental Physics 2019, 073D02 (2019).
[2] Ab initio no-core shell model study of 18-23O and 18-24F isotopes, A. Saxena, and P.C. Srivastava, Journal of Physics G: Nuclear and Particle Physics 47, 055113 (2020).
[3] First-principles results for electromagnetic properties of sd shell nuclei, A. Saxena and P. C. Srivastava, Phys. Rev. C 96, 024316 (2017).
[4] Ab initio calculations of Gamow-Teller strengths in the sd shell, A. Saxena, P. C. Srivastava, and Toshio Suzuki, Phys. Rev. C 97, 024310 (2018).

 

Zoom link: https://gsi-fair.zoom.us/j/95453783003